Composition dependence of surface photoelectric and photodegradation activities of silver antimonates with pyrochlore-like structure

Silver antimonite samples with different Ag/Sb ratios were prepared via ion exchange method through the mediator of silver proton-exchanged compounds. With the rise in the ratio of Ag to Sb in the samples, the optical band gap decreases due to the increasing contribution of Ag4d to the valence band; the surface photovoltage decreases and photocatalytic activity increases due to surface states related to the Sb3+ in the samples. The present results indicate that appropriate amount of Sb3+ is favorable for improving the photocatalytic activity under visible light irradiation.