离子极化工程调控聚合物氮化碳框架结构实现双氧水高效人工光合成OA

Molten salt polarization,leveraging ionic interactions in high-temperature molten salts,emerges as a powerful yet underexplored strategy for structural engineering.It enables precise structural engineering of polymeric carbon nitride(PCN),offering a promising strategy to boost photocatalytic H2O2 synthesis.Herein,we report a controlled modulation strategy by varying LiCl/KCl ratios in molten salts to tailor the framework structures of PCN,achieving two distinct crystalline phases:heptazine-dominated(LKCN-0.95)and heptazine-triazine donor-acceptor(D-A)junction(LKCN-0.2).By integrating experimental and theoretical analyses,we revealed that Li+-rich molten salts promote highly ordered heptazine frameworks,while K+-dominated systems enable triazine incorporation.The optimized heptazine-dominated and heptazine-triazine junction exhibited 27-fold and 42-fold enhancements in H2O2 photosynthesis(3.3 and 5.2 mmol L-1 h-1)compared to pristine PCN(0.12 mmol L-1 h-1),alongside exceptional stability over five cycles.Mechanistic studies demonstrated that structural modulation enhances charge separation and optimizes oxygen adsorption/activation for selective 2e-oxygen reduction.This work not only advances the understanding of molten salt-driven structural evolution but also provides a scalable approach for designing efficient photocatalysts toward solar-driven H2O2 photosynthesis.