Synthesis of hexagonal-like ZnO/Ag composite with excellent photocatalytic activity

Hexagonal-like zinc oxide (ZnO)/silver (Ag) composite was successfully synthesised by a flux/solvothermal route, and Ag nanoparticles are loaded on ZnO. Compared with pure ZnO, the attachment of Ag on ZnO can significantly increase visible-light absorption and reduce photoluminescence emission intensity. The photocatalytic performance of ZnO/Ag composite was evaluated by the degradation of Rhodamine B solution under ultraviolet (UV) light and visible light irradiation. The degradation rate of ZnO/Ag composite is obviously improved compared with pure ZnO and the commercial TiO2 (P25) and is more than 2.5 and 2.9 times faster than that of pure ZnO under the UV and visible light irradiation, respectively. The enhanced photocatalytic activity of ZnO/Ag composite under UV irradiation was ascribed to the formation of Schottky barriers between Ag particles and ZnO. However, the superior photocatalytic activity under visible light irradiation could be attributed to the surface plasmon resonance of Ag particles.