Facile Synthesis of Novel ZnO-CuO Hetero Nanostructures for Hydrogen Generation from Water Splitting

Description

As an n-type wide bandgap semiconductor, ZnO has been explored extensively as photoanodes in photoelectrochemical (PEC) cells for hydrogen generation from water splitting. However, ZnO can only utilize the light in ultraviolet region, which contributes less than 5% of the total energy of the solar spectrum and thus imposes a fundamental limitation on its capacity for hydrogen generation. CuO as a p-type semiconductor with a narrow bandgap can absorb light in the visible spectrum. Therefore, combining CuO with ZnO to form p-n heterostructures to enhance the light absorption by matching the solar spectrum has been widely employed to improve the PEC conversion efficiency. Different methods have been used to form ZnO-CuO hetero nanostructures that show high PEC efficiency. However, there is still a lack of facile, low-cost and scalable methods to obtain ZnO-CuO hetero nanostructures with improved PEC efficiency for hydrogen generation. In this project, we will integrate CuO nanocrystals with ZnO nanorods to form new ZnO-CuO hetero nanostructures by a novel method and then study their applications in PEC hydrogen generation. The new synthesis method is facile, low-cost and scalable. And the ZnO-CuO hetero nanostructures have increased photo-to-hydrogen conversion efficiency as compared to previously reported results for ZnO-CuO nanostructures.