In situ formation of Ag/ZnO heterostructure arrays during synergistic photocatalytic process for SERS and photocatalysis

Abstract

Abstract ZnO nanorod arrays were used to oxidize rhodamine B (RhB) and reduce Ag+ ions simultaneously under UV or visible light. The photocatalytic kinetics of RhB degradation followed a pseudo-first order with two steps, and during the synergistic photocatalysis process, Ag/ZnO heterostructural nanocomposites were generated in situ based on ZnO nanorod arrays. The Ag/ZnO heterostructure arrays were composed of Ag nanosheets with (111) plane on the basis of ZnO nanorods. The growth process of Ag nanosheets experienced a similar two-stage manner as the degradation kinetics of RhB, indicating that the change in apparent rate constants for RhB degradation was ascribed to the variation of photoinduced electrons and holes. The microstructure, composition, chemical states, and UV–visible light adsorption of reclaimed Ag/ZnO heterostructure arrays were investigated; their multifunctional applications on surface enhanced Raman scattering and photocatalytic activity under UV or simulated solar light were also discussed.