Nanoporous anodic Nb2O5 with pore-in-pore structure formation and its application for the photoreduction of Cr(VI).
An anodic film with a nanoporous structure was formed by anodizing niobium at 60 V in fluorinated ethylene glycol (fluoride-EG). After 30 min of anodization, the anodic film exhibited a "pore-in-pore" structure; that is, there were smaller pores growing inside larger pores. The as-anodized film was weakly crystalline and became orthorhombic Nb2O5 after heat treatment. The energy band gap of the annealed nanoporous Nb2O5 film was 2.9 eV. A photocatalytic reduction experiment was performed on Cr(VI) under ultraviolet (UV) radiation by immersing the nanoporous Nb2O5 photocatalyst in a Cr(VI) solution at pH 2. The reduction process was observed to be very slow; hence, ethylenediaminetetraacetic acid (EDTA) was added as an organic hole scavenger, which resulted in 100% reduction after 45 min of irradiation. The photocatalytic reduction experiment was also performed under visible light, and findings showed that complete reduction achieved after 120 min of visible light exposure.
['Alias|Nurhaswani|N|', 'Hussain|Zuhailawati|Z|', 'Tan|Wai Kian|WK|', 'Kawamura|Go|G|', 'Muto|Hiroyuki|H|', 'Matsuda|Atsunori|A|', 'Lockman|Zainovia|Z|']
D002384:Catalysis D002857:Chromium D058608:Nanopores D009556:Niobium
Anodization And heavy metal removal Chromium(VI) Nanoporous Nb(2)O(5)