Controlled synthesis of a highly dispersed BiPO4 photocatalyst with surface oxygen vacancies

Abstract

Highly dispersed BiPO₄ with surface oxygen vacancies was synthesized via a solvothermal–calcination method. It can disperse uniformly in water for more than three days and the optimum photocatalytic activity of this highly dispersed BiPO₄ was more than twice as high as that of Degussa P25 due to the oxygen vacancies. The high dispersibility is attributed to a layer of organic matter formed on the surface of BiPO₄via the solvothermal approach. Most of the organic matter can be removed by calcination at 450 °C, but a small amount remains, thus the calcined BiPO₄ retained its high dispersibility. This high dispersibility maintains a good contact between BiPO₄ and the pollutants, resulting in the efficient removal of the pollutants by BiPO₄. Besides, calcination at 450 °C also induced the formation of oxygen defects in BiPO₄, which promotes the separation of photogenerated charge carriers and thus improves the photocatalytic activity of BiPO₄.