Efficient dual-pathway H₂O₂ production promoted by covalent triazine frameworks with integrated dual active sites

The dual-pathway direct 2e(-) redox reaction is considered an efficient route for the photocatalytic generation of hydrogen peroxide (H2O2). However, the targeted design of catalysts to achieve dual-pathway reaction remains a scientific bottleneck. Herein, dual active site covalent triazine frameworks incorporating single-atom Ni and pyridine N was constructed (d-CTF-Ni), with the dual-pathway synergistically promoting H2O2 generation through oxygen reduction and water oxidation reaction. Furthermore, the pivotal role of electron transfer in enhancing catalytic activity was elucidated. Due to the presence of electron-capture centers Ni atoms and hole acceptors pyridine N, d-CTF-Ni exhibited a pronounced augmentation in the rate of H2O2 generation in pure water (869.1 mu mol center dot g(-1)center dot h(-1)), accompanied by excellent stability in multi-cycle. Experimental results and theoretical calculations indicate that the electron deficiency of N atom in pyridine promotes hole accumulation, while the single-atom Ni provides a directional pathway (Ni -> O-2) for electron transfer, thereby collectively accelerating the reaction. This study provides new insights into the electron behavior in H2O2 production at material interfaces and offers a new perspective on the dual-pathway 2e(-) redox mechanism in understanding photocatalytic H2O2 generation.