Photocatalytic CO2 reduction to CH4 mediated by MoS2@NH2-MIL-68 heterojunction with water vapor

Construction of heterojunction-based photocatalyst is a fascinating approach to improve the conversion efficiency of CO2 photoreduction. Herein, we report a series of low-cost heterojunction catalysts (x% MSNM) assembled by 1T MoS2 nanosheets and NH2-MIL-68 for photocatalytic CO2 reduction conjugated with H2O oxidation under visible-light irradiation. Notably, 8% MSNM exhibits enhanced photocatalytic activity for the photoreduction of CO2 to CH4 in the absence of organic solvent, sacrificial agent and photosensitizer. The evolution rate of CH4 can reach to 12.56 mu mol g(-1), higher than that of isolated MoS2 and NH2-MIL-68. Systematic investigations demon-strate that the 1T MoS2 fragments are uniformly dispersed on the NH2-MIL-68 surface during the assembly and crystallization process of NH2-MIL-68. Under light conditions, the NH2-MIL-68 crystals serve as light collectors to absorb visible light and generate electron-hole pairs, and the photo-excited electrons rapidly transferred to the surface of 1T MoS2, prolonging the lifetime of the photo-induced excitons. This work provides a new direction for the rational design of composite catalysts in artificial photosynthesis.