Synergistic Electron–Proton Modulation in Donor–Acceptor Polymers for NADH Regeneration and CO₂-to-Glycerol Conversion

Photochemical regeneration of NADH is essential for bioinspired redox catalysis but remains limited by inefficient electron-proton coordination. We report a donor-acceptor conjugated polymer system with rhodium centers, where electron-donating substituents (-OH, -OMe, -Me) can modulate both photo-induced charge behavior and surface reaction properties. The optimal -OH subsitutents can, on one hand, enhances dielectric screening and planarity of the polymers to, reduce the exciton binding energy and facilitate charge injection to the rhodium active centers. On the other hand, its hydrophilicity further promotes proton migration, enabling synchronized and co-localized two-electron/one-proton donation to NAD⁺ at the rhodium centers. Therefore, the optimized -OH-containing polymer achieved selective photoreduction of NAD⁺ to 1,4-NADH at a rate of 12.81 mmol g^-1 h^-1, which is one of the highest levels reported to date to our knowledge. Integrated into a photo-electro-enzyme cascade, the system synergistically couples NADH regeneration with enzymatic catalysis to achieve the first conversion of CO₂-derived aldehydes into glycerol, highlighting its potential for sustainable carbon valorization. This work establishes a facile strategy to regulate both electron and proton donation in organic photocatalysts and expands their application in solar-driven biotransformations.