Frequency-regulated pulsed electrodeposition of CuInS2 on ZnO nanorod arrays as visible light photoanodes

Vertically aligned ZnO nanorod arrays on a fluorine doped tin oxide (FTO) substrate were uniformly coated with visible light active CuInS2 nanoparticles using electrodeposition regulated by using an optimized frequency. As the diffusion of the fresh metallic precursor to the bottom of the one-dimensional nanostructure is the major challenge during electrodeposition, frequency tuning has demonstrated its effectiveness in balancing the diffusion and deposition of the secondary component (CuInS2) on the one-dimensional substrate (ZnO). The high quality of the heterojunction between CuInS2 and ZnO together with their intimate interaction facilitated efficient charge shuttling from CuInS2 to ZnO to yield a four-fold visible light response compared with traditionally synthesized CuInS2-ZnO nanostructures.