Engineering of oxygen vacancy and bismuth cluster assisted ultrathin Bi₁₂O₁₇Cl₂ nanosheets with efficient and selective photoreduction of CO₂ to CO

Abstract The photocatalytic conversion of CO₂ into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming. This work demonstrated the selective photoreduction of CO₂ to CO using ultrathin Bi₁₂O₁₇Cl₂ nanosheets decorated with hydrothermally synthesized bismuth clusters and oxygen vacancies (OVs). The characterizations revealed that the coexistences of OVs and Bi clusters generated in situ contributed to the high efficiency of CO₂–CO conversion (64.3 μmol g⁻¹ h⁻¹) and perfect selectivity. The OVs on the facet (001) of the ultrathin Bi₁₂O₁₇Cl₂ nanosheets serve as sites for CO₂ adsorption and activation sites, capturing photoexcited electrons and prolonging light absorption due to defect states. In addition, the Bi‐cluster generated in situ offers the ability to trap holes and the surface plasmonic resonance effect. This study offers great potential for the construction of semiconductor hybrids as multiphotocatalysts, capable of being used for the elimination and conversion of CO₂ in terms of energy and environment.