Abstract
? 2022 Elsevier B.V.Zinc oxide (ZnO) nanostructure has attracted great attention as an outstanding material for photoelectrochemical (PEC) water splitting devices. The surface area of ZnO plays a vital role in the distribution of narrow band gap semiconductors to maximize light absorption capability. Herein, ZnO nanorods with smooth surface (ZnO-P) were fabricated on the surface of fluorine doped tin oxide (FTO) by a hydrothermal process. Optimum deposition of cadmium sulfide (CdS) nanoparticles was obtained on the surface of ZnO-P to obtain the best PEC water splitting performance in ZnO-P/CdSx heterojunction. Employing sulfidation treatment, calcination, and hydrothermal process on ZnO-P resulted in the synthesis of branched ZnO nanorods (ZnO-B) with higher crystallinity, larger surface roughness, and lower concentration of oxygen vacancy sites compared to ZnO-P nanorods. Higher surface area of ZnO-B nanorods provided larger nucleation sites for loading of CdS nanoparticles, leading to a unique distribution of CdS nanoparticles with a uniform size. Optimum deposition of CdS on the ZnO-B sample provided a novel photoanode (ZnO-B/CdS30) with larger light absorption than the ZnO-P/CdS30 sample. Furthermore, the ZnO-B/CdS30 photoanode benefited from extensive semiconductor/solution interfaces for efficient transfer of collected photogenerated holes from the surface of CdS nanoparticles to the solution.
NSTL
Elsevier