One-Step Fabricated Sn0 Particle on S-Vacancies SnS2 to Accelerate Photoelectron Transfer for Sterling Photocatalytic CO2 Reduction in Pure Water Vapor Environment

Promoting the proton-coupled electron transfer process in order to solve the sluggish carrier migration dynamics is an efficient way to accelerate the photocatalytic CO2 reduction (PCR) process. Herein, through the reduction of Sn4+ by amino and sulfhydryl groups, Sn0 particles are lodged in S-vacancies SnS2 nanosheets. The high conductance of Sn0 particles expedites the collection and transport of photogenerated electrons, activating the surrounding surface of unsaturated sulfur (Sx2-) and thus lowering the energy barrier for generation of *COOH. Meanwhile, S-vacancies boost H2O adsorption while Sx2- increases CO2 adsorption, as demonstrated by density functional theory (DFT), obtaining a selectivity of 97.88% CO and yield of 295.06 & mu;mol g-1 h-1 without the addition of co-catalysts and sacrificial agents. This work provides a new approach to building a fast electron transfer interface between metal particles and semiconductors, which works in tandem with S-vacancies and Sx2- to boost the efficiency of photocatalytic CO2 reduction to CO in pure water vapor environment. In this work, reducing group (-NH2 and -SH) are hired to one-step reduce a fraction of Sn4+ of SnS2 to Sn0, inducing Sn0 particles grew on the S-vacancies SnS2 and constructed surface unsaturated sulfur (Sx2-). Thermodynamically, Sn0 particles interact with the SnS2 nanosheets to reduce the energy barrier for the formation of *COOH and speed up the photocatalytic CO2 reduction rate.image