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

Abstract Promoting the proton‐coupled electron transfer process in order to solve the sluggish carrier migration dynamics is an efficient way to accelerate the photocatalytic CO 2 reduction (PCR) process. Herein, through the reduction of Sn 4+ by amino and sulfhydryl groups, Sn 0 particles are lodged in S‐vacancies SnS 2 nanosheets. The high conductance of Sn 0 particles expedites the collection and transport of photogenerated electrons, activating the surrounding surface of unsaturated sulfur (S x 2− ) and thus lowering the energy barrier for generation of *COOH. Meanwhile, S‐vacancies boost H 2 O adsorption while S x 2− increases CO 2 adsorption, as demonstrated by density functional theory (DFT), obtaining a selectivity of 97.88% CO and yield of 295.06 µmol 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 S x 2− to boost the efficiency of photocatalytic CO 2 reduction to CO in pure water vapor environment.