One-pot synthesis of CdS nanocrystals hybridized with single-layer transition-metal dichalcogenide nanosheets for efficient photocatalytic hydrogen evolution

Exploration of low-cost and earth-abundant photocatalysts for highly efficient solar photocatalytic water splitting is of great importance. Although transition-metal dichalcogenides (TMDs) showed outstanding performance as co-catalysts for the hydrogen evolution reaction (HER), designing TMD-hybridized photocatalysts with abundant active sites for the HER still remains challenge. Here, a facile one-pot wet-chemical method is developed to prepare MS₂-CdS (M = W or Mo) nanohybrids. Surprisedly, in the obtained nanohybrids, single-layer MS₂ nanosheets with lateral size of 4-10 nm selectively grow on the Cd-rich (0001) surface of wurtzite CdS nanocrystals. These MS₂-CdS nanohybrids possess a large number of edge sites in the MS₂ layers, which are active sites for the HER. The photocatalytic performances of WS₂-CdS and MoS₂-CdS nanohybrids towards the HER under visible light irradiation (> 420 nm) are about 16 and 12 times that of pure CdS, respectively. Importantly, the MS₂-CdS nanohybrids showed enhanced stability after a long-time test (16 h), and 70% of catalytic activity still remained.