ZnO/TiO2 heterojunction nanorod array for efficient photoelectrochemical water splitting.

[Display omitted] • ZnO/TiO 2 heterojunction was constructed, effectively separating photo-generated carriers. • ZnO should be electrodeposited by CV on high crystallinity TiO 2 nanorods that have been calcined. • Depositing ZnO facilitates rapid electron transfer. • Introducing oxygen-rich vacancy ZnO effectively enhances the photocatalytic performance of TiO 2 photoanode. This study presents a novel approach utilizing a simple, stable, reproducible CV (Cyclic Voltammetry) electrodeposition method to deposit varying amounts of ZnO onto ordered TiO 2 (Rutile) nanorod arrays. Comprehensive investigations were conducted on the morphology, semiconductor band-gap structure of different ZnO/Rutile composites, and their performance in photocatalytic (PC) and photoelectrochemical (PEC) hydrogen production. Results demonstrate that the ZnO/TiO 2 photoanodes fabricated in this manner exhibit outstanding PC/PEC hydrogen production capabilities. Particularly noteworthy is the Z/R-15 photoanode, showcasing superior PEC performance with a photocurrent density 3.5 times higher than that of the pristine TiO 2 photoanode under equivalent conditions. Furthermore, it was observed that depositing ZnO onto highly crystalline, annealed TiO 2 nanorods yields optimal photoelectrical properties. Incorporating oxygen-rich vacancies in ZnO significantly enhances the photoelectrocatalytic performance of TiO 2 photoanodes. The CV electrodeposition method offers valuable insights for developing efficient photocatalytic hydrogen production catalysts. [ABSTRACT FROM AUTHOR]