Directed Inward Migration of S‐Vacancy in Bi₂S₃ QDs for Selective Photocatalytic CO₂ to CH₃OH

Abstract The directional migration of S‐vacancy is beneficial to the separation of photogenerated carriers and the transition of electrons in semiconductors. In this study, Bi_x/Bi_2−xS_y@carboxylic‐cellulose (CC) photocatalyst with bionic chloroplast structure is obtained by electron beam irradiation to induce S‐vacancy in Bi₂S₃@CC. The results of CO₂ photoreduction experiments demonstrate that the reduction rate of CO₂ to CH₃OH by Bi_x/Bi_2‒xS_2.89@CC‐450 samples is 10.74 µmol·g⁻¹·h⁻¹, and the selectivity is 92.82%. The results show that the inward migration behavior of the borderline S‐vacancy (b‐S_v) induces the redistribution of electrons in Bi_x/Bi_2−xS_y@CC. The Bi° clusters in Bi_x/Bi_2−xS_y@CC is conducive to adsorb CO₂, and the internal S‐vacancy (i‐S_v) is conducive to adsorb CH₃OH, which accelerate the transfer of gas‐phase products to realize the controllable conversion of CO₂ and photoreduction products at the gas–liquid–solid three‐phase interface. This study provides a new idea for the development and utilization of green photocatalysts in clean energy.