Three-dimensional ordered CdS/ZnO porous nanostructures for high-performance photoelectrochemical water splitting

Abstract

Three-dimensional ordered porous nanostructures have been considered as a key factor in developing highperformance photoelectrodes for photoelectrochemical (PEC) water splitting applications due to their high light absorption capacity and large surface area. In this study, the authors design and fabricate the three-dimensional ordered CdS/ZnO porous structures by the hard mould method. Firstly, polystyrene (PS) spheres were deposited on the indium tin oxide (ITO) conductive substrate; secondly, the gaps among the spheres were filled with ZnO material using electrochemical deposition; then the PS spheres were burned and formed the ordered porous structure of ZnO; finally, CdS nanoparticles were deposited on the surface of ZnO by wet chemical method to form a three-dimensional ordered CdS/ZnO porous structure. The photoelectrochemical water-splitting properties of the fabricated structures were studied and compared systematically. The results show that, under the irradiation of solar simulation, the efficiency of the optimised three-dimensional ordered CdS/ZnO porous structure is 3.4%, nearly 1.9 times higher than that of with 1.8% efficiency of thin-film CdS/ZnO structure at the same fabrication conditions.