Photoelectrochemical Properties of Vertically Aligned CuInS₂ Nanorod Arrays Prepared via Template-Assisted Growth and Transfer

Although copper-based chalcopyrite materials such as CuInS₂ have been considered promising photocathodes for solar water splitting, the fabrication route for a nanostructure with vertical orientation has not yet been developed. Here, a fabrication route for vertically aligned CuInS₂ nanorod arrays from an aqueous solution using anodic aluminum oxide template-assisted growth and transfer is presented. The nanorods exhibit a phase-pure CuInS₂ chalcopyrite structure and cathodic photocurrent response without co-catalyst loading. Small particles of CdS and ZnS were conformally decorated onto CuInS₂ nanorods using a successive ion layer adsorption and reaction method. With surface modification of CdS/ZnS, the photoelectrochemical properties of CuInS₂ nanorod arrays are enhanced via flat-band potential shift, as determined by analyses of onset potential and Mott-Schottky plots.