Enhanced photocatalytic activity of Bi2WO6 with oxygen vacancies by zirconium doping

To overcome the drawback of low photocatalytic efficiency brought by electron-hole recombination, Bi2WO6 photocatalysts with oxygen vacancies were synthesized by zirconium doping. The oxygen vacancies as the positive charge centers can trap the electron easily, thus inhibiting the recombination of charge carriers and prolonging the lifetime of electron. Moreover, the formation of oxygen vacancies favors the adsorption of O-2 on the semiconductor surface, thus facilitating the reduction of O-2 by the trapped electrons to generate superoxide radicals, which play a key role in the oxidation of organics. Visible-light-induced photodegradation of rhodamine B (RhB) and phenol were carried out to evaluate the photoactivity of the products. The results showed that oxygen-deficient Bi2WO6 exhibited much enhanced photoactivity than the Bi2WO6 photocatalyst free of oxygen deficiency. This work provided a new concept for rational design and development of high-performance photocatalysts. (C) 2011 Elsevier B.V. All rights reserved.