Hollow Co₉S₈/CdS Nanocages as Efficient Photocatalysts for Hydrogen Evolution

The development of highly efficient photocatalysts is the key for the application of hydrogen production. Due to the narrow band gap and high catalytic activity, Co9S8 is considered as a prospective photocatalyst for hydrogen evolution from water splitting. Nevertheless, the serious recombination of carriers on Co9S8 always results in an ultrapoor performance on hydrogen evolution. Herein, we combine CdS quantum dots on hollow dodecahedron Co9S8 to form heterostructured Co9S8/CdS nanocages by a low-energy atmospheric one-pot strategy. Owing to the Z-type heterojunction, the hollow structure, size effect of quantum dots, and abundant active sites, the separation and migration of carriers are accelerated, and the electron–hole recombination is successfully suppressed. The catalyst hollow Co9S8/CdS nanocages show a remarkable activity with the hydrogen production efficiency of 14963 μmol·h–1·g–1, which is 5.7 and 28.5 times as high as those of pure CdS and Co9S8, respectively. Besides, the long-term (up to 30 h) stability also indicates that the photocatalyst hollow Co9S8/CdS nanocages have a great potential in the photocatalytic splitting of water for hydrogen evolution.