Remarkable enhancement in solar hydrogen generation from MoS2-RGO/ZnO composite photocatalyst by constructing a robust electron transport pathway

Exploiting an efficient and noble-metal-free cocatalyst is highly desired for photocatalytic H-2 evolution from water. Here, we synthesized the MoS2-RGO/ZnO composite photocatalysts via a facile two-step solvothermal process. Through optimizing of the MoS2 and reduced graphene oxide (RGO) cocatalyst component proportion, the 0.75 wt%5G95 M/ZnO composite photocatalyst shows the highest H2 production rate of 288.4 mu mol g (1) h (1) when the amount of MoS2-RGO is 0.75 wt% and the weight ratio of RGO to MoS2 is 5: 95, which is about 14.1 times higher than the pure ZnO. More importantly, the ternary MoS2 - RGO/ZnO composite photocatalyst exhibits much higher H2 evolution activity than the Pt loaded ZnO under the same condition. The significant improvement in the H2 evolution activity is ascribed to the positive synergetic effect between MoS2 and RGO, which acts as a hydrogen evolution cocatalyst and a robust electron transport pathway, respectively. This study suggests that MoS2-RGO can serves as an efficient and noble-metal-free cocatalyst to improve the H2 production performance of ZnO by suppressing the electron-hole pairs recombination. (C) 2017 Elsevier B.V. All rights reserved.