One-pot hydrothermal synthesis of 2D–2D MoS2/CdS heterojunctions photocatalysts for photocatalytic H2 production under visible-light irradiation

Promoting the charge separation to improve photocatalytic performance of semiconductor photocatalysts is very important in the field of artificial photosynthesis. Here, a novel MoS2/CdS 2D–2D ultrathin nanosheet heterostructure was fabricated via a one-pot solvothermal route. The obtained 2D–2D MoS2/CdS nanojunction has not only provided large contact areas, but also shortened the charge-transport distance, resulting in significantly enhanced photocatalytic H2 evolution property. By optimizing the 2D MoS2 amounts in the heterojunction, the 5 wt% 2D/2D MoS2/CdS heterojunction displayed the maximal photocatalytic H2 evolution rate of 5566 μmolh−1 g−1 under visible-light irradiation in the presence of lactic acid as the sacrificial reagent, which was 10.1 times higher than that of pristine 2D CdS (516 μmolh−1 g−1). Based on the photoelectrochemical and photoluminescence spectra tests, it could be deduced that the charge separation and transfer of 2D/2D MoS2/CdS heterojunction were tremendously improved, and the recombination of photoinduced electron–hole pairs was effectively impeded. Moreover, the 2D MoS2 was used as a co-catalyst to provide the abundant active sites and lower the overpotential for H2 generation reaction. The current work would offer an insight to fabricate the 2D/2D heterojunction photocatalysts for splitting H2O into H2.