Significant enhancement in photocatalytic hydrogen evolution from water using a MoS2 nanosheet-coated ZnO heterostructure photocatalyst.

A novel MoS2 nanosheet-coated ZnO heterostructure photocatalyst was successfully synthesized via a simple hydrothermal method. Two-dimensional MoS2 nanosheets were intimately deposited onto ZnO surface to form an intimate function, which favors the charge-transfer and suppresses the recombination of the photogenerated electron-hole pairs between MoS2 and ZnO, resulting in a significantly enhanced photocatalytic activity for hydrogen evolution. The photocatalytic activities of the MoS2-ZnO composite photocatalysts with different MoS2 contents for hydrogen production were systematically evaluated. The 1.00 wt% MoS2-ZnO photocatalyst shows the highest H2 production rate of 768 μmol h(-1) g(-1) in the presence of Na2S and Na2SO3 as the sacrificial reagents, which is 14.8 times higher than that of pure ZnO. The photocatalytic activity of MoS2 as a cocatalyst for H2 evolution reaction is considerably higher than many noble metals such as Pt, Rh, Ru and Au, suggesting that MoS2 could act as a potential substitute for noble metals in photocatalytic H2 production systems. This work presents a noble-metal-free, highly-efficient, and stable MoS2 cocatalyst to suppress the recombination of electron-hole pairs of ZnO, resulting in an enhanced photocatalytic hydrogen production activity.