Improved photoelectrochemical performance by forming a ZnO/ZnS core/shell nanorod array

Abstract:

ZnO nanorod arrays (NRAs) were prepared via a facile hydrothermal method for photoelectrochemical (PEC) applications. Then, ZnS thin shell layers were deposited onto them via a facile hydrothermal treatment process for constructing a ZnO/ZnS core/shell structure. It was demonstrated that the PEC activity of a ZnO NRA is enhanced significantly after the surface modification, although there weren’t any obvious changes in the visible-light harvesting efficiency. Both the Nyquist and Mott-Schottky (M-S) plots were employed to reveal the reason, which was attributed to higher electrocatalytic activity of ZnS than that of ZnO and the resulting higher charge transfer efficiency across the solid/liquid interfaces. Finally, a schematic band model was proposed for clarifying the charge carrier transfer mechanism occurred at the interfaces.