Au nanoparticles@MoS 2 core-shell structures with moderate MoS 2 coverage for efficient photocatalytic water splitting

Abstract

Metal nanoparticles (NPs)@MoS2 core-shell nanostructures as plasmon-enhanced photocatalysts have been studied recently for efficiently photocatalytic water splitting. However, there is few reports about the effect of coverage of MoS2 on the photocatalytic water splitting. Here, we systematically study the effect of the MoS2 coverage on the photocatalytic water splitting in the Au [email protected]2 core-shell hybrid structures. The different MoS2 coverage on the Au NPs can be obtained through tuning the hydrothermal reaction time from 3 h to 18 h. We find that the moderate MoS2 coverage (i.e. 12 h) can ensure the H2O molecules penetrating the MoS2 shell and reaching to the Au-MoS2 junctions. In addition, the moderate MoS2 coverage is beneficial for the incident light to excite the strong plasmonic effect around the Au NPs core. The most efficient separation efficiency of electron–hole pairs in the Au [email protected]2 core-shell structure with the moderate MoS2 coverage is also possible reason for the high performance photocatalytic water splitting. As a result, the moderate MoS2 coverage shows the largest yield of hydrogen gas production (2110.7 μmol) among the Au [email protected]2 core-shell structures. In addition, the yield of hydrogen gas production is also obvious higher than that of the pure MoS2 spheres (880.0 μmol/g) and simple mixture of Au NPs and MoS2 sphere (1380.3 μmol/g). Our study strengthens the significance of the moderate MoS2 coverage in the Au [email protected]2 core-shell structures for high-performance photocatalytic water splitting.