Efficient Solar Light Harvesting CdS/Co₉S₈ Hollow Cubes for Z‐Scheme Photocatalytic Water Splitting

Abstract

Hollow structures with an efficient light harvesting and tunable interior component offer great advantages for constructing a Z-scheme system. Controlled design of hollow cobalt sulfide (Co₉ S₈ ) cubes embedded with cadmium sulfide quantum dots (QDs) is described, using hollow Co(OH)₂ as the template and a one-pot hydrothermal strategy. The hollow CdS/Co₉ S₈ cubes utilize multiple reflections of light in the cubic structure to achieve enhanced photocatalytic activity. Importantly, the photoexcited charge carriers can be effectively separated by the construction of a redox-mediator-free Z-scheme system. The hydrogen evolution rate over hollow CdS/Co₉ S₈ is 134 and 9.1 times higher than that of pure hollow Co₉ S₈ and CdS QDs under simulated solar light irradiation, respectively. Moreover, this is the first report describing construction of a hollow Co₉ S₈ based Z-scheme system for photocatalytic water splitting, which gives full play to the advantages of light-harvesting and charges separation.