Amino functionalized covalent organic frameworks for high-efficiency photocatalytic production of hydrogen peroxide in pure alcohols

Photocatalytic H 2 O 2 production from O 2 using covalent organic frameworks (COFs) is a promising solar-to-chemical energy conversion route. However, existing design strategies for COF-based photocatalysts are constrained by various issues, making it difficult to achieve synergistic optimization of both photogenerated charge separation efficiency and catalytic activity. In addition, compared with pure water medium, achieving efficient H 2 O 2 production in alcohols is of great significance for alcohol-mediated organic synthesis and direct alcohol fuel cells. Herein, two amide-linked COFs were fabricated via site-specific benzene ring functionalization, focusing on precise amino group incorporation. Aligned with recent advances in photocatalytic structure property relationships, amino group introduction induces significant charge density differentials in COFs, modulating donor acceptor interactions and efficiently promoting photogenerated charge separation/transport. Consequently, the 2-aminoterephthalic acid-based COF (PPTD-COF) exhibits superior photocatalytic H 2 O 2 production performance. PPTD-COF achieves a H 2 O 2 productivity of 16.23 mmol h −1 g −1 in ethanol within 0.5 h, 16-fold higher than the unmodified terephthalic acid-based COF (PTA-COF). Ethanol acts as an efficient electron-proton donor, supplying abundant H + for the oxygen reduction reaction (ORR) and facilitating proton-coupled electron transfer (PCET) for efficient H 2 O 2 generation. This work develops a site-specific functionalization strategy to tune COF electronic structures, optimize donor-acceptor interactions, and enhanced charge dynamics, highlighting potential applications in sustainable energy and environmental remediation.