New Type of BiPO4 Oxy-Acid Salt Photocatalyst with High Photocatalytic Activity on Degradation of Dye

A high photocatalytic BiPO4 with a novel nonmetal oxy acid structure is synthesized by a hydrothermal method. BiPO4 photocatalyst has an optical indirect band gap of 3.85 eV. In a comparison of BiPO4 with that of TiO2 (P25, Degussa), it is found that the photocatalytic activity of BiPO4 is twice that of TiO2 (P25, Degussa) for the degradation of methylene blue (MB) dye, while the BET surface of BiPO4 is just one tenth of that of P25. Both the high position of the valence band and the high separation efficiency of electron−hole pairs result in the high photocatalytic activity. The inductive effect of PO4 3− helps the e−/h+ separation, which plays an important role in its excellent photocatalytic activity. It may extend to the synthesis of other inorganic nonmetal salts of oxy photocatalysts with suitable band gap and high activity for the environmental purification of organic pollutants in aqueous solution.