A Novel MoS2/TiO2/Graphene Nanohybrid for Enhanced Photocatalytic Hydrogen Evolution under Visible Light Irradiation

Graphene is regarded as a potential co-photocatalyst for photocatalytic hydrogen (H-2) evolution, but its great photocatalytic ability requires tuning the band gap structure or design morphology of composites. In this study, MoS2/TiO2/graphene (MTG) nanohybrids were fabricated at varied ratios of graphene and served as co-photocatalysts for H-2 evolution. The results exhibited that the H-2 evolution of MTG-10 obtained is much better than others. The amount of hydrogen evolution was high, which was found to be 4122 mu mol g(-1) of H-2 in 5 h with photocatalytic systems, which is almost 7.5 similar to 13.4 times greater than that of previous pristine MoS2 (548 mu mol g(-1)) and TiO2 (307 mu mol g(-1)) samples, respectively. This is significantly attributed to the graphene as a bridge of MoS2/TiO2 and the incorporation of graphene, suggesting the synergistic effect of the rapid electron-transferring of photoinduced electrons and holes and the powerful electron-collecting of graphene, suppressing the charge recombination rate.

Automated summary

The MoS2/TiO2/graphene (MTG) nanohybrids were found to be highly efficient co-photocatalysts for hydrogen evolution. Among them, MTG-10 achieved the best hydrogen evolution performance, with a rate almost 7.5 to 13.4 times higher than that of pristine MoS2 and TiO2 samples. This improvement is attributed to the graphene acting as a bridge between MoS2/TiO2 and its synergistic effect in enhancing rapid electron-transferring and electron-collecting efficiency, thus suppressing charge recombination.