(342m) DFT Study on Ag Loaded 2H-MoS2 for Mechanism of Improved Photocatalytic Reduction of CO2

Transition metals modified molybdenum disulfide to improve the performance of photocatalytic reduction of carbon dioxide has been receiving much attention. Herein, a novel high-efficiency photocatalytic composite Ag/2H-MoS₂ has been constructed and simulated using density functional theory (DFT) for unveiling the mechanism of improved photocatalytic reduction of CO₂ in our experimental research. Our calcualtions about band structure, electronic and optical properties indicate that the loading of Ag atoms enhances the photocatalytic performance of 2H-MoS₂ nanosheets by transforming the photogenerated electrons from the valence band of 2H-MoS₂ to the loaded Ag atoms. Furthermore, 20wt% Ag loaded on 2H-MoS₂ containing is the most suitable for the thermodynamic requirement of reducing CO₂ to CH₃OH/CH₄ among the catalysts with different Ag loadings, and the formation of *CHO in 20wt% Ag/2H-MoS₂ is the potential-determining step, whose Gibbs free energy reduces from 2.830 eV of 2H-MoS₂ to 0.925 eV. Meanwhile the thermochemical results prodict the best path for reducing CO₂ on such a photocatalyst being CO₂→*COOH→*CO→*CHO→*CH₂O→*OCH₃→*CH₃OH→CH₄. The photocatalytic performance in reducing CO₂ of pristine 2H-MoS₂ is therefore significantly improved by loading silver. This research provides a theoretical reference for transition metal modification 2H-MoS₂ nanosheets.