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Photocatalytic synthesis based on the oxygen reduction reaction (ORR) has shown great promise for H 2 O 2 production. However, the low activity and selectivity of 2e - ORR result in a fairly low efficiency of H 2 O 2 production. Herein, we propose a strategy to enhance the proton-coupled electron transfer (PCET) process in covalent organic frameworks (COFs), thereby significantly boosting H 2 O 2 photosynthesis. We demonstrated that the construction of a hydrogen-bonding network, achieved by anchoring the H 3 PO 4 molecular network on COF nanochannels, can greatly improve both proton conductivity and photogenerated charge separation efficiency of COFs. Thus, COF@H 3 PO 4 exhibited superior photocatalytic performance in generating H 2 O 2 without sacrificial agents, with a solar-to-chemical conversion efficiency as high as 0.69%. Results indicated that a much more localized spatial distribution of energy band charge density on COF@H 3 PO 4 led to efficient charge separation, and the small energy barrier of the rate-limiting step from *OOH to H 2 O 2 endowed COF@H 3 PO 4 with higher 2e - ORR selectivity.

The photo-Fenton-like catalytic process has shown great application potential in environmental remediation. Herein, a novel photo-Fenton-like catalyst of Bi 2 WO 6 nanosheets decorated hortensia-like CoAl-layered double hydroxides (Bi 2 WO 6 /CoAl-LDHs) was synthesized via hydrothermal process. The optimized Bi 2 WO 6 /CoAl-LDHs composite performed the high-efficiency photo-Fenton-like catalytic performance for oxytetracycline (OTC) removal (98.47%) in the mediation of visible-light and H 2 O 2 . The comparative experiment, technical characterization and density functional theory calculation results indicated that the efficient photo-Fenton-like catalytic performance of Bi 2 WO 6 /CoAl-LDHs was attributed to the synergistic action of the Fenton-like process of cobalt ions in CoAl-LDHs, an internal electric field and the S-scheme heterojunction form between Bi 2 WO 6 and CoAl-LDHs, which could significantly promote the active substance formation and the photocatalytic process in the catalytic system. This study will stimulate the new inspiration of designing the efficient catalytic system for environmental remediation and other fields., (Copyright © 2021. Published by Elsevier Ltd.)