Plasmonic Bi-enhanced ammoniated α-MnS/Bi2MoO6 S-scheme heterostructure for visible-light-driven CO2 reduction

Abstract Low redox ability and severe photocorrosion limit the photocatalytic activity of metal sulfides. Herein, step-scheme (S-scheme) heterojunction composited by diethylenetriamine (DETA) ammoniated MnS (α-MnS) and Bi2MoO6 with Bi surface plasmon resonance (SPR) was successfully fabricated (Bi-5 %M/BMO). This special electron transport structure effectively suppresses the photocorrosion of α-MnS and makes photocatalysts with high redox ability. DETA was protonated to form positively charged ammonium ions and they are easy to combine with acid gas CO2, reducing the activation energy of CO2, building an efficient catalytic reaction system, and improving CO2 reduction efficiency. The CO evolution rate of Bi-5 %M/BMO (61.11 μmol g-1h−1) is 2.42, 7.89 and 5.01 times greater than that of 5 %M/BMO, pure α-MnS hollow spheres and Bi2MoO6, respectively. This indicates that Bi SPR effect can promote the separation of photon-generated electron-hole pairs dramatically. The ammoniated S-scheme heterostructure decorated with the SPR effect may provide a new perspective to design heterojunction.