A hierarchical Bi-MOF-derived BiOBr/Mn0.2Cd0.8S S-scheme for visible-light-driven photocatalytic CO2 reduction

Abstract

S-scheme heterojunctions have promising applications in photocatalytic CO2 reduction due to their unique structure and interfacial interactions, but improving their carrier separation efficiency and CO2 adsorption capacity remains a challenge. In this work, highly dispersed MOF-BiOBr/Mn0.2Cd0.8S (MOF-BiOBr/MCS) S-scheme heterojunctions with high photocatalytic CO2 reduction performance were constructed. The intimate contact between the MCS nano-spheres and the nanosheet-assembled MOF-BiOBr rods, driven by the internal electric field, accelerates the charge transfer along the S-scheme pathway. Moreover, the high specific surface area of MOFs is preserved to provide abundant active sites for reaction/adsorption. The formation of MOF-BiOBr/MCS S-scheme heterojunction is confirmed by theoretical calculations. The optimum MOF-BiOBr/MCS shows excellent activity in CO2 reduction, affording a high CO evolution rate of 60.59 µmol h−1 g−1. The present work can inspire the exploration for the construction of effective heterostructure photocatalysts for photoreduction CO2.