Boosting electron population in δ-Bi₂O₃ through iron doping for improved photocatalytic activity

We successfully stabilize the delta phase of bismuth oxide (δ-Bi₂O₃) down to room temperature through a simple hydrothermal method. The prepared δ-Bi₂O₃, which is composed of ultrathin nanosheets, possesses excellent crystallinity. When δ-Bi₂O₃ is doped with Fe³⁺, the photocatalytic activity for the mineralization of a number of refractory organic compounds is improved. The improved photocatalytic activity is caused by an increased electron population upon the Fe³⁺ doping. Additional thermal treatment through a post-calcination at 500°C under air atmosphere results in further increases of photocatalytic activity due to the improved crystallinity, extended light absorption, and better incorporation of Fe³⁺ into the host lattice.