Au nanodots@thiol-UiO66@ZnIn2S4 nanosheets with significantly enhanced visible-light photocatalytic H-2 evolution: The effect of different Au positions on the transfer of electron-hole pairs

Herein, a new type of photocatalysts, Au nanodots@thiol-UiO-66@ZnIn2S4 nanosheets (Au@UiOS@ZIS), is elaborately designed for the photocatalytic H-2 evolution from water splitting, where Au nanodots (NDs) are anchored in the pore space of thiol-functionalized UiO66 metal-organic framework (MOF) and ZnIn2S4 nanosheets are wrapped around the UiO66 MOF containing Au NDs. It is found that the different Au positions have a grateful effect on the transfer of photogenerated charge carriers. In Au@UiOS@ZIS, the photoexcited electrons transfers from ZnIn2S4 to UiOS and then to Au NDs, establishing a smooth transmission channel of electrons. As expected, the optimal sample (Au-4@UiOS@ZIS(40)) presents a high photocatalytic H-2 production rate of 391.6 mu mol/h (10 mg of catalyst) under visible light irradiation, which is 435.1, 61.2 and 10.2 times higher than that of the pure UiOS, ZnIn2S4 and UiOS@ZIS, respectively.