Tunable Band Engineering Management on Perovskite MAPbBr₃/COFs Nano‐Heterostructures for Efficient S–S Coupling Reactions

Abstract Efficient artificial photosynthesis of disulfide bonds holds promises to facilitate reverse decoding of genetic codes and deciphering the secrets of protein multilevel folding, as well as the development of life science and advanced functional materials. However, the incumbent synthesis strategies encounter separation challenges arising from leaving groups in the ─S─S─ coupling reaction. In this study, according to the reaction mechanism of free‐radical‐triggered ─S─S─ coupling, light‐driven heterojunction functional photocatalysts are tailored and constructed, enabling them to efficiently generate free radicals and trigger the coupling reaction. Specifically, perovskites and covalent organic frameworks (COFs) are screened out as target materials due to their superior light‐harvesting and photoelectronic properties, as well as flexible and tunable band structure. The in situ assembled Z‐scheme heterojunction MAPB‐M‐COF (MAPbBr₃ = MAPB, MA⁺ = CH₃NH₂⁺) demonstrates a perfect trade‐off between quantum efficiency and redox chemical potential via band engineering management. The MAPB‐M‐COF achieves a 100% ─S─S─ coupling yield with a record photoquantum efficiency of 11.50% and outstanding cycling stability, rivaling all the incumbent similar reaction systems. It highlights the effectiveness and superiority of application‐oriented band engineering management in designing efficient multifunctional photocatalysts. This study demonstrates a concept‐to‐proof research methodology for the development of various integrated heterojunction semiconductors for light‐driven chemical reaction and energy conversion.