Asymmetric p-π Conjugation Driven Charge Separation and Structural Regulation In Triazine-Cored COF for Hydrogen Peroxide Photosynthesis

Currently, as energy and environmental issues become increasingly prominent, efficient and green chemical synthesis technologies have emerged as a key research priority. The photocatalytic synthesis of hydrogen peroxide (H 2 O 2 ) has attracted widespread attention due to its ability to utilize clean energy and operate under mild reaction conditions. Covalent organic frameworks (COFs) exhibit significant application potential in this field; however, optimizing the efficiency and selectivity of H 2 O 2 synthesis through skeleton design remains a critical issue that urgently needs to be addressed. In this study, three imine-linked COFs with asymmetric p-π conjugated structures were constructed, namely TAPA-TFPT (triazine core), TAPA-TFPA (triarylamine core), and TAPA-TFPB (benzene core), and their photocatalytic performances were comparatively analyzed. Under sacrificial agent-free conditions, the three COFs generated H 2 O 2 via either the 2e – ORR pathway or the two-step 1e – ORR pathway. Among them, TAPA-TFPT exhibited the best performance, with a photocatalytic yield of 0.96 mmol g –1 h –1 . The study indicated that the triazine-core skeleton can promote the separation and transfer of charge carriers, which is the key to enhancing catalytic performance. This strategy provides important references for the photocatalytic preparation of H 2 O 2 under sacrificial agent-free conditions.