AgBr nanoparticles decorated BiPO4 microrod: a novel p–n heterojunction with enhanced photocatalytic activities

Abstract

AgBr nanoparticles loaded BiPO₄ microrods have been successfully synthesized via a facile deposition–precipitation method. XRD, FE-SEM, TEM, EIS, UV-Vis-DRS techniques were employed to characterize the phase composition, morphology and light absorption properties of the as-synthesized samples. Methylene blue (MB) and phenol (Ph) were selected as model pollutant to investigate the photocatalytic activity of the as-synthesized samples under visible-light irradiation. The experimental results show that different amount of AgBr on BiPO₄ exhibit an obvious effect on the degradation of MB and the optimum molar ratio of AgBr and BiPO₄ is 1 : 10. In particular, the photocatalytic activity of AgBr/BiPO₄ is superior to the activities of two individual photocatalyst, indicating the presence of a synergic effect between two component in AgBr/BiPO₄. On the basis of photocatalytic results and energy band diagram, the activity enhancement mechanism of AgBr/BiPO₄ composite has also been investigated. The p-type semiconductor AgBr and n-type semiconductor BiPO₄ can match each other and form a novel p–n heterojunction, thus increasing the photogenerated electron–hole pair separation efficiency. Therefore, this work provides some help for the design of novel and efficient BiPO₄-based photocatalyst with multi-components for enhancing visible-light-driven photocatalytic activity.