Facet-Selective Growth of Cadmium Sulfide Nanorods on Zinc Oxide Microrods: Intergrowth Effect for Improved Photocatalytic Performance

Well-designed architectures play an important role in accelerating charge transfer between the different components of hybrid photocatalysts. Herein, we report a simple one-step hydrothermal method to achieve a CdS/ZnO heterostructure with a novel spatial arrangement. The CdS nanorods were found to be attached to the surface of the ZnO microrods with an intimate face-to-face contact, and the heterointerfaces corresponded to {1 0 0} facets of CdS and {1 0 0} facets of ZnO. It was discovered that Zn(OH)₂ intermediates were formed at first and then grew into hexagonal ZnO microrods through a solid–solid-phase transformation. Simultaneously, CdS nuclei grew to nanorods on the {1 0 0} facets of ZnO by oriented attachment during the one-step hydrothermal process. Under visible-light irradiation, obtained CdS/ZnO exhibited enhanced photocatalytic hydrogen generation owing to improved charge separation from the two-phase intergrowth effect. This work provides a facile hydrothermal route to construct intergrown heterostructures with desired spatial arrangements for improved photocatalytic properties.