Tunable Ag Nanoparticle Decorated ZnO Nanowire Arrays and Photocatalytic Degradation of Rhodamine B

A diameter of 120 nm ZnO nanowire arrays was initially prepared on ITO glass along the (002) plane by hydrothermal method, and then its surface was uniformly anchored with a diameter of 50 nm Ag nanoparticles by dipping-photoreduction. As a solvent, ethylene glycol can effectively suppressed the self-nucleation and agglomeration of Ag nanoparticles. By changing the concentration of AgNO₃, the content of Ag on the ZnO nanowire arrays can be controllably tuned but no diameter change. The results show that, under the visible UV light irradiation, the degradation efficiency of Ag/ZnO more than twice times than ZnO nanowire arrays in RhB degradation when concentration of AgNO₃ was 5 mol/mL. Furthermore, the mechanism of Ag/ZnO degradation RhB was also investigated, and we found that the main active species is hydroxyl radicals.