Enhancing photocatalytic CO2 reduction with Z-scheme heterojunction Ag/Bi2MoO6/BiOBr composite films: Synthesis and mechanistic insights
This study reports the synthesis of a novel Z-scheme heterojunction composite film comprising Ag/Bi2MoO6/BiOBr via electrochemical processes, ion-exchange techniques, and subsequent photodeposition of silver nanoparticles. The incorporation of Ag nanoparticles exploits localized surface plasmon resonance (LSPR) effects and serves as an electron mediator, establishing a Schottky barrier that suppresses charge recombination. The optimized 1.5% Ag/Bi2MoO6/BiOBr film achieves a CO production rate of 13.65 μmol/(g·h) from photocatalytic CO2 reduction, significantly outperforming the unmodified Bi2MoO6/BiOBr film. Photocurrent and impedance analyses confirm enhanced charge separation in the Ag-modified composite. A non-linear relationship between Ag loading and photocatalytic efficiency was observed, with optimal performance at 1.5% Ag. The proposed Z-scheme mechanism elucidates the synergistic interactions among components, providing a scientific basis for rational design of advanced photocatalysts and immobilized systems for CO2 reduction. This work offers insights into the development of efficient, sustainable photocatalytic technologies for carbon capture and utilization.