Linkage structure strategy of conjugated microporous polymers for the photocatalytic synthesis of H2O2 from water and air

Artificial photosynthesis of hydrogen peroxide (H 2 O 2 ) via conjugated microporous polymer (CMP) as photocatalysts offers a promising path for solar-to-chemical energy conversion. However, the rapid recombination of photogenerated carriers and the sluggish reaction kinetics during CMP photocatalysis still remains a challenge. As a crucial strategy for regulating the pore microenvironments and charge-transfer pathways, the linkage chemistry of CMP provides a critical handle to address these limitations. Herein, three different linkages structure of CMPs with acylhydrazine (TFBE-TD), sp 2 -carbon (TFBE-PDAN) and imine (TFBE-PA) were designed as photocatalysts to elucidate the structures-performance relationships for H 2 O 2 production from water and air, without sacrificial agents. Compared with TFBE-PA, TFBE-TD and TFBE-PDAN exhibit 5.7 times and 4 times higher H 2 O 2 generation rates in pure water, respectively. This enhancement is due to the effective reinforcement of the photogenerated electron delocalization by the acylhydrazine and the sp 2 -carbon linkage structure, facilitating the electron transfer process. Furthermore, DFT calculations reveal that by adjusting the linkage structure of CMPs, the adsorption capacity of O 2 can be effectively enhanced and the reaction activation energy can be reduced, thereby promoting the ORR pathway for efficient photosynthetic H 2 O 2 production. This work establishes linkage chemistry as a key design principle for high-performance CMP photocatalysts.