Asymmetric linear conjugated polymers for stable H2O2 photosynthesis via internal polarization

Designing organic conjugated catalysts that can achieve both efficient photogenerated electron-hole pair separation and high stability during the reaction process remains a significant challenge. Engineering the electronic structure of catalysts to generate dipole fields is an effective approach to addressing the issue of electron-hole pair recombination. In this study, we engineered the electronic structure of the catalyst by incorporating inert methyl groups, resulting in asymmetric linear conjugated polymer. Under the combined influence of the donor-acceptor system and aromatic it-it stacking interactions, our designed asymmetric linear polymers exhibit dipole effects and successfully achieve enhanced charge separation kinetics. Moreover, the introduction of methyl groups as inert sites prevents the destruction of stability during the reaction process. The generation rate of H2O2 for asymmetric linear polymers is over six times greater than that of symmetric linear polymers without methyl substitution, with stability demonstrated over 100 h in cyclic experiments, indicating its potential as an efficient and stable photocatalyst. Meanwhile, experimental and theoretical calculations evidence demonstrates that the asymmetric linear conjugated polymer promotes efficient H2O2 production by the dual pathway of ORR and WOR. This study provides new insights into designing stable asymmetric organic conjugated photocatalysts to enhance charge separation dynamics and achieve efficient H2O2 production.