The Fe3O4/wood nanocompositesresult in an open-circuit voltage of 63 mV and a power density of∼52 μW/m2  under ambient conditions. The output voltage and powerdensity are further increased to 1 V and ∼743 μW/m2 under 3 suns solar irradiation. The enhancement could beattributed to the increase of surface charge, nanoporosity, and photothermaleffect from Fe3O4. The device exhibits a stablevoltage of ∼1 V for 30 h (3 cycles of 10 h) showing good long-termstability. The methodology offers the potential for hierarchical organic–inorganicnanocomposite design for scalable and efficient ambient energy harvesting.Hydrovoltaic energy harvesting offers the potential toutilizeenormous water energy for sustainable energy systems. Here, we reportthe utilization and tailoring of an intrinsic anisotropic 3D continuousmicrochannel structure from native wood for efficient hydrovoltaicenergy harvesting by Fe 3O4 nanoparticleswere inserted into the wood cell wall without gradience through anin situ synthesis. Acetone-assisted precursor infiltration enableduniform Fe3O4 formation in the bulk wood structure.An open-circuit voltage up to 1 V and a power density of ∼743μW/m2 were obtained under 3 suns solar irradiationusing Fe3O4/wood. Enhanced hydrovoltaic energyharvesting is due to increased surface charge, nanoporosity, and photothermaleffect from Fe3O4.The current success inspires the potentialfor hierarchicalorganic−inorganic nanocomposite design for scalable and efficientambient energy harvesting. Fe Power generation is stronglyinfluenced by the materials’ surface chemistry, which governsthe interfacial charging/discharging,15 materials’ nanoporous structure, and waterevaporation rate.8 Strategies to improvepower generation include maximizing the contact area with water, improvingthe charge separation ability, boosting the water evaporation rate,and so on. Therefore, materials with high nanoporosity, good waterwettability, and desirable transportation properties are needed, wherethree-dimensional structures are highlighted due to increased arealcapacity. In addition, green renewable material resources and large-scaleprocessing are favorable for further technological development.Water is the largest energy carrier onearth, containing around35% of solar energy received by the Earth, corresponding to over 2000times the world energy demand.16 When water passes through the wood substrate,charge flows inside microchannels resulting in an electrical potentialdifference along the pressure difference direction. In 2020, nativewood was first reported for hydrovoltaic energy harvesting.14 Citric acid treatment was applied to improvethe energy output. An open circuit voltage (Voc) of 0.3 V and short circuit current density (Jsc) of 0.4 μA/cm2 were achieved. Solar-assistedwater evaporation was further reported by coating the wood surfacewith carbon nanotubes, resulting in a Voc of 0.25 V, an Isc of 0.48 μA,and a power density of 350 μW/m2.17 Conductive carbonized wood with abundant hydroxyl groupswas also investigated with a Voc of 96mV, an Isc of 10.5 μA, and a powerdensity of 294 μW/m2.18 The challenges lie in the high energy intensive carbonization processingas well as low power density. Recently, our group reported hydrovoltaicenergy harvesting from charged nanoporous wood aerogel in a waterreservoir at a pH of 13.4. A Voc of 0.55V and power density of 620 μW/m2 were obtained underambient conditions,19 indicating the potentialof wood nanostructure control for enhanced power generation. Furthertailoring nanoengineered wood pH resulted in a Voc of 1 V.Wood, in this regard, is attractive for hydrovoltaic energy harvestingowing to its renewable origin and hierarchical porous structures,known for efficient water transport through transpiration. Furthermore,wood consists of cellulose, hemicellulose, and lignin, which providerich functionalities of hydroxyl, carbonyl, and phenolic groups makingthe wood structure hydrophilic with a negative surface charge.3O4,are attractive in this context, which have been intensively studiedfor water splitting.20 Among the minerals,iron oxides  are advantageous withadditional photothermal abilities,21 beneficialfor efficient water evaporation, further contributing to enhancedpower generation. Formation of a hierarchical nanostructure of ironoxides is attractive yet challenging. We hypothesize that combiningiron oxides with a hierarchical structure of wood could provide thepossibility to solve the issues and achieve efficient hydrovoltaicpower generation.Current reports of wood for water evaporation-inducedpower generationwere based on lignocellulose or carbon (carbonized wood) interfacialinteractions with water, which shows limited water charge separationabilities. Minerals, such as ZnO and Fe25 The iron oxide nanoparticle distribution is oftenlimited to the surface regions (wood surface or lumen surface) andgradience issues exist in bulk iron oxide/wood composites,26 which may trigger counter voltage generationleading to decreased performance. This hinders the optimum utilizationof wood hierarchical structures. In this work, solvent-assisted precursorinfiltration in delignified wood is proposed to solve the problems. 3O4/wood nanocomposite formationand further for solar-driven hydrovoltaic energy harvesting. Homogenouscoverage of Fe3O4 nanoparticles both on thelumen surface and in the cell wall was achieved. The Fe3O4/wood nanocomposite showed improved power generationwith a Voc of 63 mV and a power densityof 51.47 μW/m2 under ambient conditions. Under 3sun irradiation (3 kW/m2), a steady Voc of 1 V and a power density of 742.66 μW/m2 were achieved. This study demonstrates the possibility of wood mineralcomposites for efficient solar-to-vapor-assisted electricity generation.Direct iron oxide nanoparticle infiltrationis one approach, whereparticle aggregation and diffusion are considerable challenges. Insitu nanoparticle synthesis is an alternative with focuses on magneticfunctions or photostability.Ochroma pyramidale, purchased from Wentzels Co. Ltd., Sweden) were cut into 1.5 ×1.5 × 1 cm3 cubes, which have a density of around 110 g/cm3. Followingour previous methods,27 OW cubes were delignifiedin 1 wt % sodium chlorite solution with acetate buffer, which controlled pH at 4.6 under 80°C until the samples became completely white, while the lignincontent decreased from 24.9 to 2.9%. After washing several times,all the samples were solvent exchanged and kept in acetone .Original wood (OW) substratesfrom balsa wood  for 1 h undervacuum. The vacuum infiltration could ensure a homogenous distributionthroughout the whole wood. Then, the system was heated to 90 °Cfor 3 h. After thermal precipitation, the samples were transferredinto 200 mL 1.32 M sodium hydroxide solution  with potassium nitrate ([Fe2+]/[NO3–] = 0.44), whichwas heated up to 90 °C. The color of the wood immediately changedfrom red/orange to dark green/black as nanoparticles formed. Afterreacting for 10 min, 20 min, 1 h, 2 h, and 4 h, the Fe3O4/wood (FW) was washed with deionized water (DIW) thoroughlyto remove free-moving nanoparticles and ions. Fe3O4/wood with growth times of 10 min, 20 min, 1 h, 2 h, and 4h are labeled FW-10 min, FW-20 min, FW-1 h, FW-2 h, and FW-4 h respectively.Never-dried delignified wood (DW) was transferred from acetoneto 100 mL iron(II) sulfate heptahydrate solution (FeSO2), where the electrodes were held togetherusing a cotton thread.28 The device wasplaced in a Petri dish and 25 mL of DI water was added, where thewater level was up to 2–3 mm the height of wood to ensure efficientwater infiltration in the microchannels. Prior to the device fabrication,the samples were washed using DIW (conductivity of 0.3–0.4μS/cm) to remove any free ions or Fe3O4 nanoparticles. Finally, the devices were placed in a Petri dish,and DI water was poured slowly. The open-circuit potential and shortcircuit current from the wood nanogenerators were recorded in real-timeusing an electrochemical workstation ,and Keithley's DMM 7510 multimeter at 25 °C and 30% relativehumidity. The measurements were carried out by controlling the softwareon a desktop, and the sampling rate of our instrument was 10 s–1. The light was produced by a simulated solar spectrumfrom a CEL-HXF300-T3 solar simulator (3 kW/m2). The surfacetemperature of the samples was recorded by an infrared camera . The total consumption of water was measured after thecompletion of the experiment and used to calculate the effective rateof water consumption by subtracting the rate of water consumptionin an open Petri dish from the rate of water consumption with thesample. The stability of the device is characterized by three cycletests, each with a duration of 10 h, for a total of 30 h. The outputpower of a device is dependent on the internal resistance of the deviceand when the internal resistance is not known, usually, power densityis calculated using the external resistors. With the variation ofthe resistor values (resistance) in the circuit, one can know themaximum power from the device. The maximum power is achieved whenthe internal resistance of the device matches external circuits. Thus,maximum power can be drawn from a device for practical applications,and to know the maximum power density we have used an external resistorin our work. In this way, power density is calculated using the formula= V*I = I2R = V2/R and divided by area.29The hydrovoltaic energyharvesters were fabricated by sandwiching the DW or FWs between twoPt mesh electrodes  after sputtering a 10 nm Pt/Pd conductivelayer with a sputter-coater . All the imageswere observed at an acceleration voltage of 3 kV.4 into DW with and without acetone-assisted diffusionwas tested by using DW strips . After solvent exchangeby using DIW and acetone, the samples were clamped and immersed into0.1 M FeSO4 solution for 1 cm length. The FeSO4 content was converted to iron oxide for comparing the loading usingthermogravimetric analysis (TGA) under an oxygen atmosphere.The time-dependent infiltrationof FeSO2 flow of 50 mL/min.All the diffusion lengths were measuredin real-time. TGA  was performed tomeasure the composition at a heating rate of 10 °C/min from roomtemperature to 800 °C under an O3O4 crystallite sizes, theaverage grain size of Fe3O4 was estimated byScherrer’s D is the average diameterof Fe3O4 crystallites, λ represents theX-ray wavelength (0.154 nm), K refers to the Scherrerconstant (0.89), β is the full width of the peak at half maximum, and θ represents the Bragg diffractionangle. The average diameters of Fe3O4 of differentFWs were calculated using the characteristic peaks (311).X-ray diffraction (XRD)analysis was carried out by an ARL X’TRA powder diffractometer using Cu Kα radiation generatedat 45 kV and 44 mA. Scans were obtained from 10 to 80° 2θin 0.02° steps for 1 s per step. To analyze the influence ofgrowth time on FeThe compressive test was performedon a universal testing machine  under ambient conditions(25 °C and 50% RH). All the measurements were performed using1.5 × 1.5 × 1 cm samples, with a 500 N load cell at a strain rate of 1%/min. The meanvalue and standard deviation of the modulus for the DW and FW wereobtained from the three samples.The Brunauer–Emmett–Teller(BET) specific surface area was evaluated by nitrogen physisorption.Prior to the nitrogen adsorption, 0.1 g of material was degassed at90 °C for 1 day, followed by the subsequent BET analysis. Theanalysis was carried out at −196 °C under a relative vaporpressure of 0.05–0.25 with a Micromeritics ASAP 2020. The BETspecific surface area was calculated from the attained isotherms.3  and attachedto a cylindrical cell with double-sided adhesive tape. Prior to themeasurements, all the samples were conditioned by immersion in DIWto avoid swelling of wood. Measurements were carried out at 200 mbarwith N2 in a 0.001 M NaCl electrolyte solution at pH 7.3± 0.2. The mean value and standard deviation of the zeta potential(ζ) for the DW and FWs were obtained from three independentramps measured for two samples each.Zeta potential analysiswas conducted using a SurPASS Electrokinetic Analyzer (Anton Paar).DW and FW samples were cut into dimensions of 10 × 10 ×2 mm3O4 synthesis, delignification was first performedto increase the wood structure accessibility.31 The removal of lignin from the OW led to a slightly higher porosity(from 92 to 95%) in DW, with an increased BET specific surface area(BET SSA) of 8.7 m2/g (1.3 m2/g of OW). Meanwhile,a negative surface charge was introduced to the structure due to theoxidation of the C-2, C-3, or C-6 of the monomeric sugar units inpolysaccharides, leading to an increased surface charge of 241.3 μeq/gin DW from 25.9 μeq/g of OW. The increased negative surfacecharge is beneficial for Fe2+ adsorption  images (S1).sorption 2a.31 Nev) images 2 and S1.3O4 nanoparticles inside FWs with synthesis time varied from 20 minto 2 h. Compared to DW .ed to DW 2b, Fe3O4ynthesis 2c. The nynthesis 2d,e. Theynthesis 2g–i reveo the DW 2f. Fe3O4 lamella 2j–m, and lamella 2j–m. Thi3O4 nanoparticledecorationinside the wood is important to the final device performance. Thecurrent reported FWs through in situ synthesis always shows an obviousFe3O4 nanoparticle gradience. The main issuelies in the chemical diffusion during the synthesis, in particularmetal-ion diffusion. To solve the problem, acetone-assisted FeSO4 infiltration was applied. 4 diffusion into the DW, exhibiting faster diffusion in DW that issolvent exchanged to acetone (DW-Fe-acetone). In addition, higherprecursor loading is also achieved for the DW-Fe-acetone  for FeSO4 infiltratedDW without acetone exchange (DW-Fe-water) is ∼15 wt %, whichincreased to 35 wt % for DW-Fe-acetone. This indicates a higher amountof FeSO4 in the sample. 4 infiltration.Although with thicker samples, no obvious Fe3O4 nanoparticle gradient issue is present for FW-acetone after 1 hof reaction. Without acetone-assisted FeSO4 infiltration,FW samples always show a gradient even after a reaction time of 4h. More importantly, acetone-assisted infiltration ensures a homogenousdeposition of nanoparticles, which otherwise are agglomerated in theabsence of acetone-assisted infiltration  support the best efficiency of usingacetone.Obtaining uniform Fe-acetone 3b. Underltration 3d,e. In 34 ensuring acetone’spenetration into the wood cell wall and wetting all the surfaces.Therefore, DW was solvent exchanged to acetone before FeSO4 infiltration. Osmotic pressure drives the diffusion of acetone fromthe cell wall into the FeSO4 solution, while facilitatingthe diffusion of FeSO4 solution into the wood cell wall.In addition, acetone is highly volatile. Fast evaporation of acetonecould enhance the pressure difference, which further contributes tofaster metal-ion diffusion in DW. More importantly, acetone infiltrationensures a homogenous deposition of nanoparticles which are agglomeratedin the absence of acetone infiltration . As a result, the negativezeta potential of the wood bulk substrate increased from −15.4to −21.2 mV  to 1.9 m2/g (FW-20 min) and was further followed byan additional decrease to 1.6 m2/g (FW-1 h). A slight SSAincrease was obtained for FW-2 h with a value of 4.5 m2/g. The decreased SSA compared with DW is mainly due to increasedFe3O4 content, which has higher density comparedwith wood. TGA showed increased Fe3O4 contentswith increasing reaction time. FW-20 min, FW-1 h, and FW-2 h showparticle contents of 14.4, 19.9, and 22.6 wt %, respectively . A small peak at ∼25° in FW-20 min and FW-1 hcould be attributed to Fe2O3 suggesting thepresence of mixed iron oxides (JCPDS: 33-0664). Further, this peakdisappeared for FW-2 h is relatively stable and we have explored it for hydrovoltaic energyharvesting for 30 h without compromising the performance. Also, theliterature suggests that the optimum performance of wood-based hydrovoltaicdevices is obtained at a thickness of 1 cm, and no further advantagesare seen for thicker samples.14 Handlinga larger sample is a relatively small issue, which can be mitigatedby assembling many devices for a practical application.r FW-2 h 4c, suggeVoc  were evaluated for hydrovoltaic energyharvesting in terms of Voc 5a, Isc .Resistance dependencies on power density are shown in Figure S4. The maximum power density of DW was1.03 μW/m2 under an external load of 2.2 × 105 Ω. Improved power density was observed for FW-20 minwith a value of 4.46 μW/m2 under the same externalload. Further, an improved power density of 5.28 μW/cm2 was obtained for FW-1 h. It should be noted that the maximum powerdensity was obtained with an external load of 104 Ω,suggesting a change in the internal resistance of the FW samples.FW-2 h resulted in the highest power density of 51.47 μW/m2 at an external load of 104 Ω (2).The power density was measured by placing the resistorswith variableresistance in the circuit S4.Resis3O4 to decorate wood for hydrovoltaic energy harvesting. Thewide solar adsorption and strong photoresponse of Fe3O436 could contribute to water evaporationthrough photothermal conversion, which has been intensively investigated.37 For all samples, a drastically enhanced performancewas observed under 3 sun irradiation compared to that under ambientconditions mainly due to the increased water evaporation rate underhigher solar irradiation intensity. As shown in Voc and Isc for DW are ∼105 mV and ∼0.29μA, respectively. FW-20 min and FW-1 h resulted in Voc of ∼285 and ∼457 mV, whereas the Isc were ∼0.87 and ∼1.11 μA, wherea maximum power density of 8.81 μW/m2 was achievedfor DW at an external load of 4.7 × 105 Ω. FW-20min and FW-1 h resulted in the maximum power density of 68.06 and515.85 μW/m2 under 105 Ω load. TheFW-2 h resulted in the highest power density of the study, which wasfound to be 742.66 μW/m2 and it was obtained at anexternal load of 2.2 × 105 Ω. The power densityis remarkably increased by 1300% compared to ambient conditions ascribedto the excellent solar photothermal conversion property of Fe3O4. The performance of FWs under normal and threesun irradiation are comparable, or higher than the previous reports(Table S3).Increasing the water evaporation rate further improvesthe poweroutput. This is one of the main reasons using Fe∼1.11 μA5e respecincrease 5f and S53O4 nanoparticles. An electrical double layer forms fromthe adsorption of counterions. A pressure difference at the two endsof the wood leads to directional motion of counterions, resultingin an electrical potential difference  in the structureand solvent evaporation potential.fference 6b. WaterL, pore diameterof d, and the inner surface zeta potential of ζ.If only streaming potential (Vs) is consideredfor potential generation, the potential could be described accordingto the following eq 0, εr, σ, and μ are the electrical permittivity of vacuum,the relative permittivity of the solution, the conductivity, and theviscosity of the solution, respectively. ΔP is the external pressure difference. When DIW is applied as thereservoir, ε0, εr, σ, andμ are constant. External pressure difference (ΔP) and wood surface zeta potential (ζ) are criticalvariables for potential generation.In the system, wood could be considered as bundlesof cylindricalcapillary tubes with a length of 3O4 particlescontributes to enhanced ζ   by surface hydroxylation for enhanced hydrovoltaic energyharvesting.21 There could also be contributionsfrom the thermoelectric effect, solvent evaporating potential38 and ionovoltaic voltage generation.39 Therefore, For FWs, the interactionbetween water molecules and Fehanced ζ 1. As shond Fe3+) 6c. This OHbonds 6d.4 Henc42J is the volume flux(or effective water evaporation rate), and γ is the porosity.The increased water evaporation rate was observed under solar irradiationespecially for FWs due to the high photothermal conversion abilityof Fe3O4. The photothermal conversion abilityof Fe3O4 is supported by the higher sample surfacetemperature under solar irradiation . The rate of total water consumption increased over 5 times under3 sun irradiation . The effectivewater consumption under ambient conditions were 0.47, 0.82, 0.76,and 1 mL/h for DW, FW-20 min, FW-1 h, and FW-2 h /effective water consumption rate (J), and woodsurface zeta potential (ζ). This indicates the presence of otherimportant factors that influence the power generation, such as thenanoporosity. Pores at the nanoscale could have a significant effecton the output performance by building an overlap of diffuse partsof electric double layers. The effect could be over the influenceof the surface zeta potential. In this work, FW-2 h shows higher outputperformance than the FW-1 h, even if the latter has a higher zetapotential. This could be assigned to the pore size distribution/porositydifference at the nanoscale, which plays a vital role in hydrovoltaicenergy harvesting. As shown in It should be noted that the measured 3O4 nanoparticles,FWs not only show higher power generation, which could be attributedto the increased surface charge, nanoporosity, and photothermal effectfrom Fe3O4, but also good stability. The deviceperformance stability was estimated by running the samples multipletimes. After 3 cycles , the FW-2 h retained the96.7% Voc generated . However, with the assembly of many similar devices,the power output can be enhanced, which can run small electronics,such as calculators, watches, and so on. The key advantage of thesedevices is continuous power generation for a longer time, which canalso be stored in a capacitor for later use.With the incorporationof Feenerated 6h. This 3O4 nanoparticles were successfullyincorporated into a hierarchical wood structure for hydrovoltaic energyharvesting through an in situ synthesis. Acetone-assisted precursorinfiltration ensures nanoparticles’ uniform distribution throughoutthe wood structure and into the cell wall. A Voc of 63 mV, Isc of 1.17 μA,and power density of ∼52 μW/m2 were obtainedfor FW-2 h, which is over 165 times higher compared with the OW. Theenhanced performance was ascribed to the higher surface charge, thenanoporosity, and the water dissociation ability of Fe3O4 under ambient conditions. By further enhancing theevaporation rate by using solar energy, a Voc of 1 V and the highest power density of 742.66 μW/m2 were obtained, which was mainly due to the enhanced rate of effectivewater consumption and the photothermal effect of Fe3O4. The current success inspires further investigation of othermineralized wood for energy harvesting under solar irradiation througha careful structure design. The assembled wood-based devices can beused for continuous power generation over long periods of time.In conclusion, Fe


H)-one and tetrazole are a class of nitrogen-containing heterocyclic compounds that play an important role in drug design and are an important part of many biological and industrial compounds. In this study, aluminium-based ionic liquid grafted onto a biochar surface (BC/[TESPMI]AlCl4) was synthesized and used as a catalyst for the synthesis of a series of biological derivatives including 2,3-dihydroquinazolin-4(1H)-ones in ethanol at reflux conditions and tetrazoles in PEG-400 at 110 °C. All products were obtained with good selectivity and yield of 90 to 97%. The catalyst was thoroughly characterized using various techniques such as thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), inductively coupled plasm (ICP), and transmission electron microscopy (TEM), which confirmed the successful chemical grafting. This methodology has several advantages, including shorter reaction time, high yield of product, and recyclability of the catalyst. The catalyst remained active for five reaction cycles.2,3-Dihydroquinazolin-4(1 H)-one and tetrazole are a class of nitrogen-containing heterocyclic compounds that play an important role in drug design and are an important part of many biological and industrial compounds.2,3-Dihydroquinazolin-4(1 In the chemical activation method, fresh biochar is mixed with activation agents such as ZnCl2, KOH, H2SO4, K2CO3, H3PO4, etc., and heated at high temperatures in an inert gas flow.4–6 In a physical activation method, biochar is pyrolyzed and exposed to carbon dioxide or a controlled stream-flow, or a combination of both at above 700 °C.7 In this way, most of the reactive points of the carbon can be removed, and the pores can open and interconnect.8 Therefore, its surface area can significantly be modified.9,10 Several factors can be affected on the chemical-activation of biochar such as the concentration and temperature of the activation agent, feedstock type, and other factors.11 In addition, biochar is a low-cost, big surface area, high water-holding capacity, and pyrogenic carbon-rich material.12–19 Therefore, these carbon-based materials have a good potential to be used as heterogeneous catalysts even in many industrial applications, and they can be used as catalysts directly.20–23Biomass is a valuable carbon-neutral resource with unique properties, such as tailored surface functional groups and a large surface area. It is readily available and can be used as an inexpensive starting material in various fields. One of the most important uses of biomass, is the preparation of biochar using the pyrolysis process. Biochar obtained from the pyrolysis of biomass has low porosity, high specific surface area, and limited surface functional groups.24–26 Typically, ionic liquid formation occurred when an organic cation was combined with an inorganic or organic anion.27 According to qualitative and semi-qualitative studies, ionic liquids can replace conventional catalysts with the advantage that they do not cause any toxicity in the reaction mixture.28 Immobilization of ionic liquid on the surface of biochar has emerged as a superb platform for the synthesis of unique heterogeneous catalysts.29Besides, ionic liquids have emerged as more environmentally friendly alternative solvents than conventional solvents and have attracted major attention from researchers.30–32 The low toxicity and high physiological activity of tetrazoles led to the fact that these materials continue to be highly regarded as widely used materials.33–35Tetrazole compounds have been investigated for over 100 years and applied in a variety field of science such as gas-generating compositions, organic synthesis, biochemical and pharmaceutical applications, and some others.H)-ones are a significant class of heterocyclic compounds that contain nitrogen. They have gained considerable interest due to their varied therapeutic and pharmacological properties, which include hepatoprotective, vasodilator, antidebrillatory, antipyretic antiatherosclerotic, and analgesic effects.362,3-Dihydroquinazolin-4 1,2-diaminobenzene Schiff base complex, SiO2-[Cu-BDACDABSBC] as a heterogeneous catalyst in the presence of ascorbic acid and a solution of water/i-PrOH  media at reflux condition is described. The yields of product have been achieved in the range of 75–95% for 3–8 hours.38 Dehghani and co-workers reported salen complex of Cu(ii) supported on superparamagnetic Fe3O4@SiO2 nanoparticles for the synthesis of tetrazole in DMF at 120 °C in 83–92% of product.39 Sharghi and co-workers reported 4′-phenyl-2,2′:6′,2′′-terpyridine–copper(ii) complex immobilized onto activated multi-walled carbon nanotubes [AMWCNTs-O-Cu(ii)-PhTPY] .40 And the other work has been published using ZnO, Zn hydroxyapatite, Zn/Al HT , FeCl3–SiO2, Sb2O3, γ-Fe2O3, BaWO4 Cu2O, CdCl2 and ZnS .41–45 Many of these works have disadvantages such as low product efficiency, high reaction temperature, use of toxic solvents to promote the reaction, use of high amounts of catalyst, use of catalysts that cannot be recycled, etc. Also, there are several reports on the use of nano catalysts for the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives such as solvent-free, mechanochemically scalable synthesis of 2,3-dihydroquinazolin-4(1H)-one using Brønsted acid catalyst reported by Gauravi Yashwantrao and co-workers .46 The other strategies for the preparation of these compounds have been reported by Sun et al. in 2018 47 and Pathare et al. in 2019 .48 Aqueous Facile Synthesis of 2,3-Dihydroquinazolin-4(1H)-One Derivatives by Reverse Zinc Oxide was reported by Jie Mou and the other work in 2020 .49 However, most of these protocols have limitations, such as excess oxidant, complicated reactions, harsh reaction conditions (up to 100 °C), tedious work-ups, non-renewable and toxic solvents, non-reusable catalyst, low yields and long reaction times. All of these approaches reveal that the catalytic formation of these compounds is still challenging and that the area demands to be developed further. Consequently, based on our research on heterogeneous supported catalysts50–53 to introduce a catalyst that does not have any of the drawbacks stated for the mentioned catalytic systems, herein, we reported aluminium-based 1-(triethoxysilyl) propyl-3-methylimidazolium chloride ionic liquid grafted on ([TESPMI]Cl)-biochar (BC/[TESPMI]AlCl4) as a high active, low-cost, reusable, environmentally friendly, and a heterogeneous nature catalyst. Furthermore, the catalytic performance of BC/[TESPMI]AlCl4 was investigated in the synthesis of 5-substituted 1H-tetrazole and 2,3-dihydroquinazolin-4(1H)-one derivatives.Several reports have been published on the use of nano catalysts in the synthesis of tetrazole derivatives. For example, a review summarized the most important nano-based catalyst approaches used in the synthesis of 5-substituted 12.2.1.3, and all other reagents, chemicals, and solvents were purchased from Merck, Aldrich, Fluka and were used without additional purification.1-methylimidazole, (3-chloropropyl) triethoxysilane, AlCl2.2.−1. FT-IR spectra were recorded with KBr pellets using a Bruker FT-IR spectrometer (model VRTEX 70). And the transmission electron microscopy (TEM) images were obtained by a Zeiss – EM10C microscope with operating voltage at 100 kV. The elemental Al content catalyst was determined by PerkinElmer Optima 7300D inductively coupled plasma (ICP). The BET test was performed by using a BELSORP MINI II instrument.Powder X-ray diffraction (PXRD) of catalyst were recorded on a Holland Philips diffractometer . SEM, EDS and EDS-mapping analysis were performed by using a FESEM-TESCAN MIRA3 scanning electron microscope. The thermogravimetric analysis (TGA) curves are recorded between 30 and 800 °C in air with heating rate of 10 °C min2.3.2 gas that scanned at 0.3 L min−1. In continuous, it introduced the porcelain crucibles into the heating zone with a 0.03 L min−1 rate of nitrogen flow. This process continues for 1 and then 2 hours. After that, the heating zone of porcelain crucibles was cut down, and cooled with N2 sweep with 0.3 L min−1 for 30 minutes. Resulting, a black solid is obtained which is biochar.54Biochar was obtained by placing dried chicken manure (500 g) in a porcelain crucible and pyrolyzed at the common temperature range of pyrolysis means 400 °C to 800 °C. We reached the required temperature after approximately 30 minutes of heating with the carrier N26 After that, the reaction mixture was washed with n-hexane several times to get a pure yellowish viscous ionic liquid ([TESPMI]Cl).In a round-bottomed flask equipped with a condenser, a mixture of 1-methylimidazole (1 mmol) and (3-chloropropyl) triethoxysilane (1 mmol) was reflexed at 100 °C for 12 h, according to recent research.BC/[TESPMI]Cl was prepared by dissolving 1.5 mmol of [TESPMI]Cl and 1 g of biochar in toluene and stirred at 90 °C for 24 h. The resulting product was purified by washing with EtOH for several times and drying at 60 °C and labeled as BC/[TESPMI]Cl.−1.The ionic liquid content (weight stability) was determined by gravimetric method after complete drying. The amount of [TESPMI]Cl per gram of support was measured to be 1.13 mmol g3 and 0.5 g of BC/[TESPMI]Cl in EtOH (20 mL), and the reaction mixture was stirred at 60 °C for 20 h. The desirable product was obtained after filtering, washing with the mixture of ethanol/water, and dried at room temperature. This product labeled as BC/[TESPMI]AlCl4.Finally, the nanocatalyst was prepared by dissolving of 1 mmol of AlCl2.4.H-tetrazoles were synthesized from a mixture of 1 mmol of benzonitrile and 1.2 mmol of sodium azide in PEG-400 solvent in the presence of 50 mg BC/[TESPMI]AlCl4 for enough time at 110 °C. The end of reactions has been determined by TLC method and the obtained data for several derivatives were summarized in 4 catalyst has been separated from the reaction mixture by a simple filtration. After that, the reaction mixture was transferred to a decanter funnel containing water, HCl and ethyl acetate. The combined organic layers were dried over anhydrous Na2SO4, then filtered, and the solvent was removed under reduced pressure and finally the crude product was purified using a silica gel plate.5-Substituted-12.5.4 was added and stirred under reflux condition for appropriate reaction time (To a mixture of 2-aminobenzamide (1 mmol) and aldehyde (1 mmol) in ethanol (5 mL), 30 mg of BC/[TESPMI]AlClion time . The end3.4 nanocatalyst was afforded according to a three-step operationally simple process, as shown in 4).72,73 The synthesized BC/[TESPMI]AlCl4 catalyst has been characterized by various techniques such as BET, SEM, FT-IR, EDAX, TGA, WDX, XRD, ICP and TEM.The BC/[TESPMI]AlCl3.1.4 was examined by XRD analyses, as shown in θ = 17–30°, which reflects amorphous carbon.54,55 Furthermore, peaks observed at 2θ = 19.87°, 21.90°, 26.66° and 31.74° in the XRD pattern of BC/[TESPMI]AlCl4 confirm the synthesis of the catalyst.The internal structures of BC/[TESPMI]AlCl4 catalyst, which results are shown in 54 The second weight loss is related to the elimination of organic groups that are immobilized on the surface of biochar.54 The third mass loss are corresponding to the continued biochar pyrolysis.The thermal stability of inorganic and organic components can be obtained by thermogravimetric analysis (TGA) at different temperatures. Therefore, this technique was used to identify the thermal stability of the BC/[TESPMI]AlCl4 catalyst was explored using scanning electron microscopy (SEM) technique and depicted in The morphology of BC/[TESPMI]AlClEnergy-dispersive X-ray spectroscopy (EDS) is widely used in the characterizations of the content of different elements in the nanostructure's frameworks. Based on this analysis, C, Cl, Si, O, N and Al species are present on the structure of the catalyst .4 catalyst, as illustrated in 4.To further characterize the catalyst, wavelength dispersive X-ray spectroscopy (WDX) was employed to determine the elemental distributed of BC/[TESPMI]AlCl4 was measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Based on the ICP results, 0.73 mmol of Al was loaded onto 1.0 g of the catalyst which shows a high loading capacity for this nanocatalyst.The exact amount of aluminium in BC/[TESPMI]AlCl4 was investigated by TEM  and 0.01 cm3 g−1 . Meanwhile, the pore diameter value of BC/[TESPMI]AlCl4 catalyst is 8.0 nm, which is higher than of the BC substrate.54 Considering that the pore diameter of BC/[TESPMI]AlCl4 catalyst is between 2 and 50 nm.The porosity properties of BC/[TESPMI]AlClanalysis . Accordi4 catalyst, the FTIR spectra were taken, as shown in −1 wave number, reveling oxygen-containing functional groups stretching vibrations such as phenol, alcohol, and carboxylic acid groups. The peaks around 3000 cm−1 are assigned to CH2 stretching vibrations.54 The IR spectrum of [TESPMI]Cl  scale" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg>N and CC groups in imidazolium rings, respectively. In addition, the bands at the interval 1085, 783 and 485 cm−1 are attributed to the stretching vibrations of Si–O–Si. As can be observed in −1 and 3405 cm−1 are related to the presence of –CN– and O–H groups on the surface of BC/[TESPMI]Cl. In −1 and 904 cm−1 which confirms the formation of BC/[TESPMI]AlCl4 catalyst.To identify the functional groups in biochar (BC), [TESPMI]Cl, ionic liquid functionalized biochar (BC/[TESPMI]Cl) and BC/[TESPMI]AlClESPMI]Cl  shows ab3.2.4 catalyst was investigated in the synthesis of 1H-tetrazole derivatives. First, optimization of the reaction condition is considered in the reaction between benzonitrile and sodium azide. In this stage, the effect of solvent, amount of catalyst, and temperature were examined to the synthesis of corresponding tetrazole.The catalytic performance of BC/[TESPMI]AlCl4 catalyst. After optimizing the amount of catalyst, we attempted to optimize the best solvent to perform this reaction in the presence of 50 mg of BC/[TESPMI]AlCl4 -one derivatives. To get the optimized reaction conditions, several parameters have been explored in the reaction condensation of 4-chlorobenzaldehyde and 2-aminobenzamide.Also, the catalytic efficiency of BC/[TESPMI]AlCl4 catalyst and in the presence of biochar as catalyst. The results show that there was no reaction in either of these two reactions even after long reaction time  were explored  and polar aprotic solvents -one because it is green, safe, environmentally friendly, and easier work-up.Preliminary results illustrated the maximum yields in EtOH , entry 4H)-one derivatives were synthesized in 90–97% yields under optimized conditions.The optimized reaction conditions were extended to a series of aldehydes with electron donor and electron acceptor functional groups. As shown in 4 is illustrated in 56 At first, the catalyst is coordinated with C PBM data was replaced with SVG by xgml2pxml:<glyph-data id="z.tbd" format="PBM" resolution="300" x-size="17" y-size="11" xml:space="preserve">0000000000000000000000000000000000000000000000000000111111111111111000000000000000000011111111111111100000000000000000001111111111111110000000000000000000000000000000000000000000000000000</glyph-data><svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="23.636364pt" height="16.000000pt" viewBox="0 0 23.636364 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>Created by potrace 1.16, written by Peter Selinger 2001-2019</metadata><g transform="translate scale" fill="currentColor" stroke="none"><path d="M80 600 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z M80 440 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z M80 280 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z"/></g></svg>N functional groups, intermediate (1) formed. N3 ion attacked on intermediate (1) by [3 + 2] cycloaddition reaction and formed intermediate (2), which finally formed the corresponding tetrazole (3).A purposed mechanism for the tetrazole formation catalyzed by BC/[TESPMI]AlClH)-ones in the presence of BC/[TESPMI]AlCl4 catalyst. Based on this mechanism, initially, the imidazolium cations and Al-based nanocatalyst interacted with carbonyl group in aldehyde. Next, the activated carbonyl is attacked by 2-aminobenzamide's NH2, which imine intermediate (2) is formed. Afterwards, imine intermediate (2) and catalyst produces the intermediate (3). Finally, the target 2,3-dihydroquinazolin-4(1H)-ones (4) was formed by the nucleophilic cycloaddition of amide nitrogen to the imine active group.Also, 4 catalyst has been done to prove the heterogeneous behavior and no metal leaching of the BC/[TESPMI]AlCl4 catalyst in the preparation of 2,3-dihydroquinazolin 4(1H)-one derivatives. In this stage, the reaction between 4-chlorobenzaldehyde with 2-aminobenzamide has been tested under the optimal conditions. At the end of the reaction, the catalyst was recovered from the reaction by filtration. The recovered catalyst washed with ethanol and drying it at 50 °C. The recovered catalyst was reused in the next similar reaction. We continued this experiment up to 5 times. Finally, it was observed that the catalytic activity of BC/[TESPMI]AlCl4 was not reduced significantly -one derivatives as a reusable, highly effective, and eco-friendly nanocatalyst. The nanocatalyst was prepared through a three-step procedure and characterized using various techniques including EDX, BET, FT-IR, SEM, PXRD, TEM, ICP and TGA. The nanocatalyst could be easily separated from the reaction mixtures and reused up to five times while maintaining its effectiveness. This approach has several benefits, including the use of a reusable and eco-friendly catalyst, a green solvent, mild reaction conditions, low catalyst loading, and the ability to achieve high yields without requiring a chromatographic column to isolate products.In summary, aluminium-based ionic liquid immobilized biochar surface was used for the sustainable and green synthesis of 5-substituted 1There is no conflict of interest for authors.RA-013-D3RA06440A-s001


The effect of conversion temperature was investigated. The TEM examination of the prepared magnetic Fe3O4 (np)@CSs showed the formation of Fe3O4 (np) in a matrix of carbon sheets as a coated layer with surface functional groups including carbonyl and hydroxyl groups. Removal of dyes such as methyl orange, methylene blue, and neutral red was achieved using fabricated Fe3O4 (np)@CSs which were prepared at 250 °C, 400 °C, and 700 °C in a weak acidic medium. By studying the contact time effect for the adsorption of methylene blue, neutral red, and methyl orange, using the fabricated Fe3O4 (np)@CSs which were prepared at 250 °C and 400 °C, equilibrium occurred between 120 min and 180 min. In addition, the first-order and second-order kinetic models were applied to the adsorption data. The results revealed that the adsorption data fit better with the second-order kinetic model. Furthermore, the Freundlich model was found to be more suitable for describing the process of the separation of the dyes onto Fe3O4 (np)@CSs which were prepared at 250 °C and 400 °C, suggesting heterogenous surfaces and multi-layer adsorption.Thermal treatment is applied for the direct conversion of palm stalk waste to Fe Pollution is a global problem that is increasing day by day; therefore, it is necessary to assess this problem and develop solutions to prevent its associated negative impacts. As a result of water pollution, deaths and diseases occur all over the world ,2,3. TheCurrently, the adopted techniques to control dye pollution include coagulation, co-sedimentation, ion exchange, membrane techniques, and adsorption processes. The purification methods must exhibit high efficiency, simplicity, low cost, and easy utilization of local resources. Adsorption is the most interesting technique, and many materials can be used as sorbents. Typical adsorbents are mainly activated carbon, metal oxides, and zeolites . Low-cos3O4 nanoparticles coated with a single or double organic layer [3O4), hematite (α-Fe2O3), and maghemite (γ-Fe2O3) are the most common forms [3O4 composite using a co-precipitation process for the removal of chromium (VI), with an adsorption capacity of 75.76 mg g−1. In addition, the coprecipitation process was applied to produce magnetic biochar from cotton which produced an adsorbent that promised separation efficiency for aniline removal [3O4-C-Pt) that were synthesized and applied for 5-hydroxymethylfurfural oxidation [3O4–activated carbon from wastepaper, in which the Fe3O4 was fabricated first and then combined with the activated carbon of the wastepaper [3O4 magnetic nanoparticles (Fe3O4 (np)@CSs). In addition, this study aimed to investigate the potential of the fabricated Fe3O4 (np)@CSs for the adsorption of some dyes including methylene blue, methyl orange, and neutral red. Furthermore, we assessed the kinetic and isotherm models for the adsorption of the tested dyes onto the fabricated Fe3O4 (np)@CSs.Magnetic materials have great advantages as they can be easily rotated using an external magnetic field, and they can be controlled and directed towards the pollutant or separated from it . One of ic layer ,21. Theron forms ,23. As aon forms . Magnetion forms . In prevon forms . The reaon forms . The magon forms  preparedon forms ,30,31,32 removal . Zhang exidation . Anton exidation . Ferronestepaper . These m3O4 (np)@CSs, a 10 g sample of the palm stalk fine powder was mixed with 6.75 g of iron (III) chloride hexahydrate in a sulfuric acid medium to form a paste-like mixture. The mixture was then heated in a muffle furnace at various temperatures of 250 °C, 400 °C, and 700 °C in the near absence of oxygen. Then, the formed Fe3O4 (np)@CSs were ground and washed with deionized water and ethanol several times. The obtained Fe3O4 (np)@CSs were examined by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Zeta potential analysis was applied to assess the surfaces charge variation of the prepared adsorbents including Fe3O4 (np)@CSs prepared at 250 °C, 400 °C, and 700 °C, with the pH variation from 2 to 12, using a Zeta nanosizer, Malvernpanalytical, Worcestershire, UK. A 0.05 g of Fe3O4 (np)@CSs prepared at 250 °C, 400 °C, and 700 °C was dispersed in 10 mL of NaOH (0.01 M), and the pH was adjusted to the desired pH values of 2, 4, 6, 8, 10, and 12 by adding drops of HCl or NaOH. The mixtures were exposed to ultrasonic waves for one minute, and then analyzed by zeta potential.The applied chemicals including iron (III) chloride hexahydrate, sulfuric acid, sodium hydroxide, hydrochloric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, methylene blue, methyl orange and neutral red were purchased from Sigma Aldrich, St. Louis, MO, USA. Palm stalk waste was collected from Riyadh city, divided into pieces between 5 cm and 10 cm, then washed with distilled water and dried in an oven at 105 °C. The palm stalk waste pieces were then ground to a fine powder. For the preparation of Fe3O4 (np)@CSs was mixed with 20 mL of methylene blue (100 mg/L), methyl orange (100 mg/L), and neutral red (100 mg/L) solution separately. The pH was controlled by adding 2 mL phosphate buffer solution and adjusted by adding drops of HCl or NaOH to the desired pH . The mixtures were then shaken for 240 min at 150 rpm. Then, the Fe3O4 (np)@CSs adsorbents were separated from the aqueous medium by an external magnetic field, and the remaining dye solution was analyzed using UV–visible spectroscopy. The batch treatment processes were conducted in three replicates. In addition, the blank experiments were carried out at the same time during the dye adsorption processes. Then, the adsorption capacity for dye uptake was calculated by evaluating the dye concentration before and after the treatment process, using the following equation:0 represents the dye initial concentration, Ce is the dye equilibrium concentration, V is the solution volume in liters, and M is the Fe3O4 (np)@CSs adsorbent mass in grams.The batch method was used to investigate the adsorption of methylene blue, methyl orange, and neutral red, as described in the previous literature ,38. FiveAfter investigation of the pH effect, pH 6 was selected for further study of methylene blue and methyl orange, while pH 2 was selected for further evaluation of neutral red. The previously described batch adsorption process was repeated to study the effect of contact time in the range of 10 min to 900 min at a dye concentration of 120 mg/L, an adsorbent dose of 0.02 g, a shaking rate of 150 rpm, and a temperature of 25 °C.3O4 (np)@CSs were subjected to kinetic and equilibrium modeling and compared with other adsorbents from the literature.The effect of methylene blue, methyl orange, and neutral red dye concentration was investigated in the range 50 mg/L to 500 mg/L, at a contact time of 360 min, an adsorbent dose of 0.02 g, a shaking rate of 150 rpm, and a temperature of 25 °C. The adsorption data of methylene blue, methyl orange, and neutral red onto Fe3O4 nanoparticles embedded into carbon sheets (Fe3O4 (np)@CSs). The produced nanocomposite exhibited magnetic properties which facilitate the separation of adsorbent using an external magnet after the adsorption of dyes. The nanocomposites of Fe3O4 as the core and carbon sheets as the shell improve the stability of Fe3O4 (np) during adsorption application and prevent leaching in an acidic medium. In addition, the whole particles of Fe3O4 (np)@CSs exhibit magnetic properties which enable easy filtration using the magnetic properties and avoid the difficulties associated with the adsorbent separation [3O4 nanoparticles. The temperature effect was investigated at 250 °C, 400 °C, and 700 °C. 3O4 (np)@CSs adsorbent. The preparation process at 250 °C produced an adsorbent material that poses high carbon content which is formed simultaneously with Fe3O4 (np) @CSs led to the formation of well-coated Fe3O4 (np) with particle sizes between 100 nm to 300 nm which is embedded in carbon sheets as the shell, as presented in 3O4 (np)@CSs, led to the formation of Fe3O4 (np) with particles sizes between 50 nm and 100 nm, which are surrounded by a thin carbon shell due to the formation of ash and loosening parts of sample organic content, resulting in a poorly coated carbon shell (3O4 (np)@CSs, most notably at higher temperatures of 400 °C and 700 °C. These results agreed with those of Hu et al., who reported the formation of pure Fe3O4 (np) at higher heating temperatures of 450 °C and 650 °C [Activated carbon is a highly stable adsorbent material with a stable performance as an adsorbent in an acidic or basic medium. Herein, the combination of carbon materials with iron oxide was applied to produce Feparation ,40,41. H3O4 (np) A,B. The on shell G,H. By con shell C,F,I. Thon shell C, while on shell F and 700on shell I. This id 650 °C .3O4 (np)@CSs at 250 °C, 400 °C, and 700 °C ) [3O4 and α Fe2O3 (np). However, the fabricated samples at 250 °C (3O4 (np)@CSs at 400 °C exhibited the clearest peaks.XRD was applied to identify the crystallinity in the formed structure of the fabricated Fed 700 °C . It can t 400 °C b which w5-1436)) . In contt 250 °C a exhibit3O4 (np)@CSs at 250 °C, 400 °C, and 700 °C, the peak related to the Fe–O bond in the structure of the Fe3O4 nanoparticles was detected in the three tested samples at approximately 570 cm−1. In addition, the carbonyl and hydroxyl groups appeared between 1600 cm−1 and 1700 cm−1 and 3300 cm−1 and 3450 cm−1, respectively, in the case of fabricated Fe3O4 (np)@CSs at 250 °C @CSs prepared at 250 °C, 400 °C, and 700 °C was calculated and is presented in 3O4 (np)@CSs prepared at 250 °C and 400 °C showed higher adsorption capacities compared with those prepared at 700 °C, which may be attributed to the loss of carbon content. In addition, the weak acidic medium was the most suitable for adsorption compared with the strong acidic or basic mediums, except for neutral red which possesses a higher adsorption capacity at pH 2 in the case of Fe3O4 (np)@CSs prepared at 400 °C (3O4 (np)@CSs prepared at 250 °C, 400 °C, and 700 °C, a possible explanation for the adsorption mechanism is provided in 3O4 (np)@CSs, resulting in an effective adsorption process. The point of zero charge is important to illustrate the response of the adsorbent surfaces due to the pH change. The zeta potential has been applied to evaluate the effect of pH on the surface charge of the prepared Fe3O4 (np)@CSs prepared at 250 °C, 400 °C, and 700 °C. As presented in 3O4 (np)@CSs prepared at 400 °C and 700 °C, and for Fe3O4 (np)@CSs prepared at 250 °C, the surface charge became around 0.4 at pH 12. However, the adsorbent prepared at 700 °C showed higher surface electrostatic charge, and it exhibited the lowest adsorption capacity. This may be attributed to ash formation at a higher temperature which leads to lower carbon content, as confirmed by EDS examination (3O4 (np)@CSs enabled the required matrix to carry and protect magnetic iron oxide nanoparticles, as well as the carbonyl active sites attracting dye molecules during adsorption [3O4 (np)@CSs may involve Van der Waals forces, electrostatic interaction and dipole–dipole interaction between lone pairs of electrons in the dyes molecules and iron oxide structures which cause the positively charged Fe3O4 (np)@CSs surfaces, as well as between the carbonyl groups and S centers in methylene blue dye [The removal of dyes was applied to investigate the efficiency of the prepared magnetic carbon sheets as an adsorbent for water purification. The applied dyes included methylene blue, neutral red, and methyl orange. The pH of the adsorbent/adsorbate solution was studied from 2 to 12 and the adsorption capacity for the fabricated Fet 400 °C B. The stmination I. The prsorption ,47,48. Tblue dye .3O4 (np)@CSs prepared at 250 °C and 400 °C, the equilibrium occurred at a time between 120 min and 180 min, as shown in 3O4 (np)@CSs reaching a steady state due to the saturation of the Fe3O4 (np)CS adsorbent surfaces. The adsorption capacities of Fe3O4 (np)@ CSs-250 °C were 95 mg/g, 77 mg/g, and 93 mg/g for methylene blue, neutral red, and methyl orange, respectively, while for Fe3O4 (np)@ CSs-400 °C were 92 mg/g, 99 mg/g, and 90 mg/g for methylene blue, neutral red, and methyl orange, respectively. As is shown in 3O4 (np)@CSs showed rapid adsorption of dyes; however, the adsorption capacity in the case of magnetic Fe3O4 (np)@CSs prepared at 400 °C was the best. The dye adsorption onto porous adsorbents may include three steps: adsorption on the outer material surfaces, dye diffusion into the internal pores, and adsorption onto the internal surfaces [By studying the contact time effect for the adsorption of methylene blue, neutral red, and methyl orange using the fabricated Fesurfaces .3O4 (np)@CSs prepared at 250 °C and 400 °C.In addition, the kinetic models of the pseudo-first-order and the pseudo-second-order kinetics were applied to the adsorption data, which fit better with the second-order kinetic model A–D. The 1 and qe were calculated (lculated .3O4 (np)@CSs prepared at 250 °C and 400 °C.The pseudo-second-order kinetic model in its integrated form of Equation (3) , was app3O4 (np)@CSs, according to the Langmuir and Freundlich models, was investigated.The equilibrium status correlating to the concentrations of dyes with the adsorption capacities during the removal of methylene blue, neutral red, and methyl orange onto magnetic Fe0max (mg/g) is the maximum saturated monolayer adsorption capacity of the magnetic Fe3O4 (np)@CSs, Ce (mg/L) is the adsorbate concentration at equilibrium, qe (mg/g) is the amount of adsorbate uptake at equilibrium, and KL (L/mg) is a constant associated with the affinity between the dyes and magnetic Fe3O4 (np)@CSs.The Langmuir Equation (4) was applied:2, for the adsorption of methylene blue, neutral red, and methyl orange onto magnetic Fe3O4 (np)@CSs @CSs  had loweF (mg/g)/(mg/L) n is the Freundlich constant, and n (dimensionless) is the Freundlich intensity parameter.The Freundlich Equation (5) was applied:2, for the adsorption of methylene blue, neutral red, and methyl orange onto magnetic Fe3O4 (np)@CSs (3O4 (np)@CSs prepared at 250 °C and 400 °C, especially in the case of methylene blue, suggesting the presence of heterogeneous surfaces and multi-layer adsorption.The correlation coefficient, R(np)@CSs A,B (Tabl(np)@CSs  revealed3O4 (np)@CSs was compared with others in the literature @carbon sheets (Fe3O4 (np)@CSs). The fabricated adsorbents of Fe3O4 (np)@CSs prepared at 250 °C, 400 °C, and 700 °C, exhibit positively charged surfaces under a pH range up to 10 as indicated from zeta potential measurements. However, the Fe3O4 (np)CS adsorbent prepared at 250 °C and 400 °C showed higher efficiency for the removal of methylene blue, neutral red, and methyl orange dyes. The thermal conditions at 400 °C were considered optimal for the formation of Fe3O4 in the entire structure of Fe3O4 (np)@CSs, as indicated by XRD. The fabricated Fe3O4 (np)@CSs at 250 °C and 400 °C showed high efficiency and fast performance for the removal of methylene blue, neutral red, and methyl orange. The adsorption capacities of Fe3O4 (np)@ CSs-250 °C were 95 mg/g, 77 mg/g, and 93 mg/g for methylene blue, neutral red, and methyl orange, respectively, while for Fe3O4 (np)@ CSs-400 °C, the adsorption capacities were 92 mg/g, 99 mg/g, and 90 mg/g for methylene blue, neutral red, and methyl orange, respectively. In addition, the reported adsorption process in this work is considered as a fast and effective method for the removal of dyes from wastewater. The practical and future applications of the prepared Fe3O4 (np)@CSs may include the adsorption of various pollutants such as pesticides, polychlorinated biphenyls, and/or heavy metals from wastewater. In addition, thermal treatment can be applied in future investigations to incorporate various metal oxide nanoparticles into waste-derived carbon for environmental and sustainable purposes.The thermal treatments at 250 °C, 400 °C, and 700 °C for palm stalk waste together with the iron (III) chloride hexahydrate in an acidic medium led to the formation of Fe


Removalof the solvent under reduced pressure affords the activated compoundV(TCNE)2, which exhibits a T* value of590 K and permanent microporosity (Langmuir surface area of 850 m2/g). The porous structure of V(TCNE)2 is accessibleto the small gas molecules H2, N2, O2, CO2, ethane, and ethylene. While V(TCNE)2 exhibits thermally activated electron transfer with O2, all the other studied gases engage in physisorption. The T* value of V(TCNE)2 is slightly modulated uponadsorption of H2 (T* = 583 K) or CO2 (T* = 596 K), while it decreases more significantlyupon ethylene insertion (T* = 459 K). These resultsprovide an initial demonstration of microporosity in a room-temperaturemagnet and highlight the possibility of further incorporation of small-moleculeguests, potentially even molecular qubits, toward future applications.Materials that simultaneouslyexhibit permanent porosity and high-temperaturemagnetic order could lead to advances in fundamental physics and numerousemerging technologies. Herein, we show that the archetypal molecule-basedmagnet and magnonic material V(TCNE) 2 (TCNE = tetracyanoethylene) exhibitsmagnetic order aboveroom temperature and permanent microporosity and can accommodate incorporationof various gas molecules.The molecule-based magnet and magnonicmaterial V(TCNE) Herein, we show that V(TCNE)2 can indeed be obtained in a highly porous form through activationof the parent material V(TCNE)2·0.95CH2Cl2. Notably, V(TCNE)2 can reversibly adsorbvarious small molecular guests, including H2, N2, O2, and ethylene, suggesting its potential for applicationsin magnetic sensing and magnon-based quantum transduction.Although dozens of studies have been conducted onthe chemicaland physical properties of variants of V(TCNE) pillars 1, with d2·0.95CH2Cl2 was synthesized usinga modified version ofa previously reported procedure.30 In brief,a yellow dichloromethane solution of freshly prepared V(CO)632 2·0.95CH2Cl2 precipitated from thereaction solution as a dark green powder, and the presence of 0.95equiv of dichloromethane was ascertained by combustion elemental analysis(see the 2 was obtained by gently heating V(TCNE)2·0.95CH2Cl2 under reduced pressure (<10μbar) at 30 °C for 20 h. Note that the solvated and activatedmaterials are notoriously unstable and must be handled with care.Indeed, previous studies have reported that the chemical compositionand physical properties of solvated V(TCNE)∼2 canvary substantially depending on the reactants, synthetic conditions,and subsequent handling of the product.33 In addition, thesematerials have been reported to decompose even when stored under aninert atmosphere at ambient temperature.34 Accordingly, the materials reported here were stored at −25°C when not in use, and the preparation of samples for analysiswas carried out immediately following removal from cold storage, underconditions described in the Supporting Information. All measurementswere performed within three weeks of the chemical synthesis.The material V(TCNE) see the  was addesee the . Activat2·0.95CH2Cl2 over the temperature range 2–300 K toconfirm the high magnetic ordering temperature of this solid. A plotof magnetization versus temperature  = M(0)(1 – (T/T*)α), to estimate a characteristic temperature of T* = 646 K (see Section 1.2 ofthe Supporting Information). Note that T* convergesto Tc in systems where T* is lower than the decomposition temperature. Since the converseis true for V(TCNE)2 and a precise determination of Tc was therefore not possible, T* serves as an indirect probe for characterizing the strength ofthe exchange interaction. Notably, this is a considerably higher transitiontemperature than previously reported for dichloromethane-solvatedbulk V(TCNE)x .19 The high T* value here may reflect a higher-puritymaterial with fewer defects to arrest magnetic correlation, resultingfrom the synthetic conditions used and careful handling of the product.Indeed, this value is similar to the value of T*≈ 600 K estimated for high-quality thin films of V(TCNE)2 obtained through chemical vapor deposition,23 and it represents the highest characteristic temperature yet reportedfor a bulk coordination solid.18Variable-temperature dc magneticsusceptibility data were collected for V(TCNE)perature 2a reveal2 yielded T* = 590 K, only slightlylower than the temperature of 646 K determined for V(TCNE)2·0.95CH2Cl2. The relatively small decreaseof 56 K upon activation is attributed to structural changes resultingfrom solvent removal—which could originate from the partialcollapse of a porous structure—and modified magnetic exchangestrength stemming from slight distortions of the vanadium coordinationenvironment.40 Resolvation of the activatedV(TCNE)2 sample by soaking in dichloromethane for 1 h yieldeda material with magnetic properties distinct from that of V(TCNE)2·0.95CH2Cl2, indicating the presenceof subtle irreversible changes upon activation .A Bloch fit to the resulting magnetization versustemperature data2a for acII ions and TCNE•– linkers further,variable-field magnetization data were collected for V(TCNE)2·0.95CH2Cl2 and V(TCNE)2 atselected temperatures between 3 and 300 K 2 at 300 K. Ferromagnetic resonance spectroscopyis a technique analogous to nuclear magnetic resonance or electronparamagnetic resonance spectroscopy, but it operates on magnetic domainsin ferromagnetic or ferrimagnetic materials instead of nuclear orelectron spins.42 Notably, the FMR spectrumfor V(TCNE)2·0.95CH2Cl2 featuresa peak with a resonance field of ∼3550 G, close to that characterizedfor thin films of V(TCNE)2 prepared via chemical vapordeposition .22 Further, this spectrum exhibits a Lorentzian line shapesimilar to that observed for V(TCNE)2 thin films. In contrast,the FMR spectrum for activated V(TCNE)2 features a peakat a lower resonance field of ∼3320 G with a long tail to higherfields. The FMR line widths of the solvated and activated samplesare both significantly larger than line widths measured for V(TCNE)2 thin films .43 Relative to V(TCNE)2·0.95CH2Cl2, the greater line width forthe activated sample may be explained by the formation of defectsand regions of structural inhomogeneity upon desolvation, which wouldresult in a reduction of the magnetic correlation length and createinhomogeneous local resonances, leading to the greater overall peakbroadening. Crucially, the presence of a well-resolved peak in theFMR spectrum for activated V(TCNE)2 highlights the feasibilityof magnon-based transduction involved in the porous form of the material.We turned to ferromagnetic resonance (FMR) spectroscopyas an additionalprobe of the magnetic structure of V(TCNE)2 exhibits permanent porosity,we first collected N2 adsorption data at 77 K . To the best of our knowledge,V(TCNE)2 represents the first example of a porous room-temperaturemagnet, and it demonstrates the merit in using paramagnetic organiclinkers to simultaneously facilitate strong magnetic exchange andgive access to porous structures.44 Importantly,pore size distribution analysis performed based on Ar adsorption dataobtained at 87 K  revealedthat V(TCNE)2 contains pores with a diameter of ∼9.7Å, suggesting that insertion of various molecules with smallerkinetic diameters is possible. Indeed, this pore diameter obtainedfrom Ar uptake data is consistent with the calculated structure depictedin 2/g was calculatedfor the aforementioned proposed structure of V(TCNE)2,further supporting the presence of microporosity in V(TCNE)2 (see Section 1.6 in the Supporting Information).To investigatewhether activated V(TCNE) at 77 K 3. Steep ectivelyS3. To thectivelyS3. To th2 (see Section 1.5 of the Supporting Information), reproducing the aforementionedcalculated structure as a starting point 2·0.5C2H4 and V(TCNE)2·0.25C2H4, were modeled by relaxing superstructures of one ethylenemolecule within a supercell of two and four unit cells of V(TCNE)2, respectively . By comparing the ground-state energy of the ethylene-loaded systemswith that of separated V(TCNE)2 and ethylene, we determinedformation energies of 0.22 and 0.25 eV for V(TCNE)2·0.5C2H4 and V(TCNE)2·0.25C2H4, respectively. The relatively low formation energiessupport the feasibility of adsorbing ethylene within V(TCNE)2. Further, DFT calculations were performed to assess possible differentorientations of the adsorbed ethylene molecules. Relaxations withvarious starting orientations of ethylene converged to two differentfinal orientations .For V(TCNE)2·0.5C2H4, phononcalculations indicate modes associated with the rotation of ethylenemolecules at phonon frequencies as low as 6.4 meV , suggesting a possible low-energyrotational degree of freedom of the ethylene molecule. Together withthe N2 adsorption data and pore size analysis, these computationalfindings provide strong evidence that the porous structure of V(TCNE)2 can accommodate small-molecule guests.As an initial test case, we carriedout density functional theory(DFT) calculations to probe the feasibility of inserting ethyleneinto the pores of V(TCNE)ng point 1.28 Two 2 at 298 K. As shown in 46 To further explore the nature of the guest uptake, we collectedan ethane isotherm at 298 K for activated V(TCNE)2. Ethaneuptake in the material is very similar to ethylene uptake, and thedata overlay at the lowest pressure points (2 is 1.64 mmol/g (0.50 ethane molecule per formula unit), slightlyhigher than the ethylene capacity. Interestingly, slight hysteresisis visible in the adsorption/desorption data for both gases, whichcould indicate some degree of flexibility in the structure of V(TCNE)2. Overall, given the similar kinetic diameters and polarizabilitiesof ethylene and ethane,47 these resultssupport physisorption of ethylene in V(TCNE)2. However,preliminary results from DFT calculations  and magnetic characterization of ethylene-dosed V(TCNE)2 (see below) suggest that the interaction between ethyleneand V(TCNE)2 may be more complex. Nitrogen uptake in thematerial at 291 K is very low e points 4a. At 1.ulations S23 and m2 adsorption properties of V(TCNE)2 at cryogenictemperatures 2 is less steep, and the material adsorbs4.42 mmol/g (1.36 molecules per formula unit) at 1.2 bar. The isothermdata at 77 and 87 K were fit using a three-site Langmuir–Freundlichmodel (Table S1), and the correspondingfit parameters were used with the Clausius–Clapeyron relationto obtain an isosteric heat of adsorption for H2 of −7.7kJ/mol . This value is consistentwith moderately strong physisorption and is more exothermic than valuesassociated with H2 binding in two well-studied materialsfor physisorption-based H2 storage, Zn4O(bdc)3 50 and the ultraporous framework[Al3(μ3-O)(H2O)2(OH)(PET-2)] .51 The relatively stronger physisorptionmay be attributed to the smaller pore size of V(TCNE)2 (∼9.7Å) relative to MOF-5 (12 and 15 Å)52 and NU-1501-Al (17 and 22 Å)51 andfavorable van der Waals interactions between the framework and theH2 molecules.We also examined theHeratures 4b. At 772 adsorptiondata for V(TCNE)2 obtained at 291 K reveal gas uptake upto a capacity of 2.32 mmol/g(0.71 molecule per formula unit) at 1.0 bar (2 desorptionthan in the case of ethylene or ethane. To further probe interactionsbetween V(TCNE)2 and CO2, we used insitu diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS). Spectra were collected for samples of activated V(TCNE)2 dosed with 100 mbar of CO2 at 195, 250, and 298K, and in each case, the v3 mode of CO2 wasobserved at 2335 cm–1, within the typical rangefor CO2 physisorbed in porous frameworks 2.Low-pressure CO 1.0 bar 4c, indicameworks 5.53−55 I2 and considering the reducingnature of VII, weexplored the potential of this material to carry out redox-mediatedoxygen adsorption. At 195 K, the material adsorbs O2 andachieves a capacity of only 2.38 mmol/g (0.73 molecules per formulaunit) at 1.0 bar 2 is initially extremely steep,reaching a value of 2.5 mmol/g at only 3 mbar before plateauing ata value of 2.7 mmol/g (0.83 molecule per formula unit) at 1.0 bar.Desorption data obtained at 298 K revealed more pronounced hysteresisand more O2 retained than at 195 K. After being held underdynamic vacuum (<10 μbar) for ∼3 h, the sample adsorbedonly minimal O2 ,indicating irreversible dioxygen binding at this temperature and/oran insufficiently high regeneration temperature. The temperature-dependentO2 adsorption data obtained for V(TCNE)2 likelyoriginate from a kinetic barrier to thermodynamically favored electrontransfer. In such a scenario, insufficient thermal energy would beavailable at 195 K to overcome this barrier, such that no electrontransfer occurs and O2 is taken up via physisorption. However,more thermal energy is available at 298 K to induce electron transferfrom V(TCNE)2 to O2. Given the absence of exposedVII sites in the material, O2 uptake at 298K must occur through an outer-sphere electron transfer mechanism,as previously reported for example for the reduced frameworks AxFe2(bdp)3 .57 The latter materials also exhibit steep and irreversible O2 uptake at room temperature, although O2 uptake becomespartially reversible at higher temperatures.Having established a guest-accessibleporous structure for V(TCNE) 1.0 bar 4d, behav2 after dosing with 100 mbar of CO2, H2, ethylene, and O2 to investigate the impact of theseguest molecules on the magnetic properties of the material . Plots of magnetization versus temperature obtained for activatedV(TCNE)2 before and after dosing with CO2 andH2 exhibit similar profiles . This relativelynarrow range of T* values suggests that the physicaland electronic structures of the porous V(TCNE)2 frameworkdo not significantly change upon uptake of CO2 and H2, as such changes would very likely lead to larger variationsin magnetic exchange and thus the T* value. Thisscenario is further supported by the similar line widths and resonancefields of the FMR signals of activated V(TCNE)2 and samplesdosed with CO2 and H2 .Dc magneticsusceptibility data were collected for samples of activated V(TCNE)2 dosed with 100mbar of ethylene revealed a much lower characteristic temperatureof T* = 459 K, corresponding to a 22% decrease fromthat of the activated sample. Based on the structures derived fromDFT calculations, the insertion of 0.25 equiv of ethylene resultsin a unit cell expansion by approximately 1.5% in volume, associatedwith a lengthening of calculated V–Nequatorial andV–Naxial interatomic distances from 2.06 and 2.06Å to 2.12 and 2.13 Å, respectively. This structural expansionpresumably acts to decrease the spatial overlap of V-based dπand TCNE•–-radical-based π orbitals,in accord with the decreased band dispersions of V-derived spin-upvalence states by ∼0.3 eV and the reduced hybridization betweenVII and TCNE•– . Consequently, this reduced orbital overlap shouldinduce a weakening of the magnetic coupling between spin-bearing VII and TCNE•– units and thus a decreasein T*. In addition to these structural factors, thedecrease in T* may also partly stem from a shiftof charge density from electron-rich dπ orbitals of VII to the unfilled π* orbitals of the TCNE•– linkers.In contrast, a Blochlaw fit to magnetization versus temperaturedata for a sample of activated V(TCNE)2·0.95CH2Cl2 withan estimated characteristic temperatureof T* = 646 K, the highest reported to date for anycoordination solid. Careful activation of V(TCNE)2·0.95CH2Cl2 yields the permanently porous material V(TCNE)2, which behaves as a bulk ferrimagnet above room temperaturewith an estimated T* = 590 K. Significantly, theactivated compound exhibits a rigid pore structure with an empiricallyderived average pore diameter of ∼9.7 Å and reversiblyadsorbs H2, CO2, and ethylene via physisorption.At 195 K, the material also reversibly physisorbs O2. Whilethe presence of H2 or CO2 guest molecules doesnot significantly impact the magnetic properties of V(TCNE)2, introduction of ethylene into the porous structure results in asignificant decrease in characteristic temperature to T* = 459 K, likely reflecting stronger interactions with the TCNE•– radical linkers of the material. Future workwill entail the incorporation of paramagnetic guest molecules, includingsmall molecules that can act as qubits, and subsequent studies ofmagnon–spin quantum transduction.We have synthesized high-qualitybulk V(TCNE)4N)[V(CO)6] and V(CO)6 were prepared according to the previouslyreported procedures.31 Carbon, hydrogen, and nitrogenelemental analyses were obtained from the Microanalytical Laboratoryat the University of California Berkeley.Unless otherwise noted, allmanipulations were carried out under an argon atmosphere in an MbraunMB200MOD glovebox. Glassware was dried in an oven at 150 °C forat least 12 h and allowed to cool in an evacuated glovebox antechamberprior to use. Dichloromethane was dried using a commercial solventpurification system made by JC Meyer Solvent Systems and stored over3 Å molecular sieves prior to use. Tetracyanoethylene (96% purity)was purchased from Sigma-Aldrich, purified through vacuum sublimationat 140 °C and 40 μbar, and subsequently stored under anargon atmosphere. The compounds 6  in 3 mL of dichloromethanewas added dropwise in a 20 mL glass scintillation vial containinga colorless solution of TCNE  in 12 mL of dichloromethane.The dark blue-green suspension was stirred for 10 min until the evolutionof CO gas ceased. The vial was sealed with a polytetrafluoroethylene-linedcap, and the reaction mixture was stirred at 25 °C for 1 h. Theresulting suspension was filtered with a Nylon membrane filter, washedwith CH2Cl2 (4 × 2 mL), and dried to yield127 mg (96%) of product as a dark green powder. Two batches of sampleswere prepared using an identical synthetic procedure. Note that thechemical and physical properties of solvated V(TCNE)x (x ≈ 2) are known to vary across differentbatches of samples depending on the purity of the reactants, the syntheticconditions, and subsequent handling of the material.33 Anal. Calcd for VC12.95H1.9N8Cl1.9 (%): C, 40.11; H, 0.49; N, 28.89. Found (%): C, 39.85;H, 0.41; N, 29.14.The synthesis of V(TCNE)2·0.95CH2Cl2 (70.0 mg) was transferred to a preweighed analysistube. The tube was capped with a Micromeritics TranSeal and evacuatedby heating at 30 °C under dynamic vacuum (<10 μbar)for 20 h when an outgas rate of less than 3 μbar/min was recorded.The sample was then transferred to a solvent-free N2 gloveboxto yield 51.2 g (92%) of product as a dark green powder, which wasimmediately transferred for storage at −25 °C. Anal. Calcdfor VC12.06H0.12N8Cl0.12 (%): C, 46.39; H, 0.04; N, 35.89. Found (%): C, 46.43; H, 0.12;N, 35.88.The compound V(TCNE)2-filled glovebox,a typical sample of 30–50 mg was transferred to a preweighedanalysis tube, which was capped with a Micromeritics TranSeal andevacuated by heating at 30 °C with a ramp rate of 0.2 °C/minunder dynamic vacuum for 20 h. The evacuated analysis tube containingthe degassed sample was then carefully transferred to an electronicbalance and weighed again to determine the mass of sample. The tubewas then transferred back to the analysis port of the gas adsorptioninstrument. The outgas rate was again confirmed to be less than 3μbar/min. For all isotherms, warm and cold free-space correctionmeasurements were performed using ultrahigh-purity He gas . Oil-free vacuum pumps and oil-free pressureregulators were used for all measurements to prevent contaminationof the samples during the evacuation process or of the feed gasesduring the isotherm measurements. Pore-size distributions were calculatedusing the DFT method with a quenched solid-state DFT (QSDFT) modelof Ar at 87 K adsorbed in carbon with cylindrical pores, as implementedin the Quantachrome VersaWin software.Gas adsorption isothermswere collected between 0 and 1 bar using a volumetric method witha Micromeritics ASAP 2020 instrument. In an N2 was dispersed in dry diamond powder by gently mixing the two powders in a N2-filled glovebox.After cooling to 195 K, 100 mbar of CO2 was dosed intothe cell, which was then sealed. Spectra were collected continuouslyuntil no changes were observed. Collection was repeated at 250 and298 K.Infrared spectra were collectedusing a Bruker Vertex 70 spectrometer equipped with a glowbar source,KBr beam splitter, and a liquid-nitrogen-cooled mercury–cadmium–telluridedetector. A custom-built diffuse reflectance system with an IR-accessiblegas-dosing cell was used for all measurements. The sample temperaturewas controlled by an Oxford Instruments OptistatDry TLEX cryostat,and the sample atmosphere was controlled by a Micromeritics ASAP 2020Plusgas adsorption analyzer. A sample of desolvated V(TCNE)2 were prepared by adding powder to a 5 mm i.d. × 7 mm o.d. quartztube containing a raised quartz platform. These samples included solvatedV(TCNE)2·0.95CH2Cl2 (11.8 mg),activated V(TCNE)2 (11.2 mg), activated V(TCNE)2 dosed with CO2 (11.0 mg), activated V(TCNE)2 dosed with H2 (14.9 mg), activated V(TCNE)2 dosed with C2H2 (12.0 mg), and activated V(TCNE)2 dosed with O2 (10.4 mg). Powder samples were restrainedwith a plug of compacted glass wool that prevented crystallite torqueingbut enabled gas dosing. The gas-dosed samples were prepared by attachingquartz tubes containing activated V(TCNE)2 to a MicromeriticsASAP 2020 HD gas adsorption analyzer and dosing with CO2, H2, or ethylene to 100 mbar and O2 to 150mbar at 25 °C . A sampleof activated V(TCNE)2 resolvated with CH2Cl2 (14.4 mg) was also prepared as follows: inside an argon glovebox,activated V(TCNE)2 was soaked in dichloromethane solutionfor 1 h, filtered on a polypropylene membrane filter (0.45 μm),and dried briefly at ambient temperature under reduced pressure beforebeing loaded into a quartz tube. After sample preparation, all quartztubes were flame-sealed while the sample was cooled with liquid nitrogen.All magnetic measurements were performed using a Quantum Design MPMS2SQUID magnetometer from 3 to 300 K at applied magnetic fields rangingfrom 0 to ±7 T. ac susceptibility measurements were performedwith an oscillating field of 4 Oe with a frequency from 10 to 100Hz . Diamagneticcorrections were applied to the data using Pascal’s constantsof χD = −0.00019390 emu mol–1 for the solvated samples and χD = −0.00015356emu mol–1 for the activated and gas-dosed samples.Samples of V(TCNE)2 to a Micromeritics ASAP 2020 gas adsorption analyzer and then dosingwith CO2 and H2 at 25 °C. All quartz tubescontaining samples were flame-sealed while the sample was cooled withliquid nitrogen under a static gas atmosphere. Ambient-temperatureFMR spectroscopy was carried out using a Bruker EPR spectrometer configuredwith an X-band bridge providing 200 μW of applied microwavepower and a modulation field and frequency of 0.03 G and 100 kHz,respectively. Under standard operation, the microwave frequency istuned between 9 and 10 GHz for optimal microwave cavity performancebefore the measurement, and then the frequency is fixed while thedc field is swept during the measurement.A typical sampleof ∼30 mg of material was transferred to a 25 cm long quartztube with an outer diameter of 4 mm. The gas-dosed samples were preparedby attaching the quartz tubes containing activated V(TCNE)2·0.95CH2Cl2, activated V(TCNE)2, or “aged” V(TCNE)2 (stored under Ar at 295 K for 1 month) was pressed into apellet with a custom-built copper screw cell . Electronic conductivity values (Table S2) were determined through both I–V measurements and electrochemical impedance spectroscopyusing a Bio-Logic VMP-3 multipotentiostat fitted into an argon atmosphereglovebox. Data were analyzed with the EC-Lab v10.41 software packagefrom Bio-Logic. I–V profileswere collected for a ±1 V voltage window and fitted with Ohm’slaw, V = I·R, where V is the voltage, I is the current, and R is the resistance. The resistance and volume of each pressedpellet sample were used to calculate the conductivity, σ, usingthe equation σ = L/(R·A), where L and A are the thicknessand contact area of a cylindrical pellet, respectively. For impedancemeasurements, unless otherwise noted, all data were collected at 250mV ac and 0 V dc bias, with a frequency sweep range of 1 MHz to 1Hz with sampling of 15 points per decade, averaging 10 measurementsper frequency. Data were fitted to a model circuit. Similar electronicconductivity values of ∼1 × 10–3 S cm–1 were measured for V(TCNE)2 and V(TCNE)2·0.95CH2Cl2 , indicating that the material is stable to activation, and thesevalues are consistent with previous electronic conductivity valuesreported for V(TCNE)x·yCH2Cl2 .59 In contrast, a decreasedelectronic conductivity of ∼9 × 10–5 S cm–1 was measured for V(TCNE)2 afterit had been stored under Ar atmosphere at 295 K for 1 month .A powder sampleof ∼10 mg of V(TCNE)