Highly Efficient Hydrogen Peroxide Production Over S-Scheme G-C₃N₄/COF Heterojunction Through Dual-Channel...

Photocatalytic hydrogen peroxide (H₂O₂) production has traditionally been dominated by a single reaction pathway, namely the oxygen reduction reaction (ORR). However, this approach is limited by low efficiency and a dependence on sacrificial agents. In this study, we introduce a pioneering radiofrequency plasma-assisted strategy for constructing an S-scheme heterojunction composed of g-C₃N₄ and a triazine-based covalent organic framework (COF). This novel heterostructure enables simultaneous dual-channel H₂O₂ generation via both the ORR and water oxidation reaction (WOR) under visible light without sacrificial reagents. The optimized composite, gTD-30, achieves a remarkable H₂O₂ production rate of 2017 µmol g^-1 h^-1 in pure water, thus surpassing the performance of the individual components g-C₃N₄ and TaPPY-DHTA (TD)-COF by 10.9 and 3.6 times, respectively. This composite also exhibited outstanding stability over multiple cycles in diverse aqueous environments. Using advanced characterization techniques and theoretical modelling, we demonstrated that plasma treatment not only enhanced the interfacial contact but also induced a strong internal electric field and band alignment, thereby unlocking exceptional charge separation and redox capability. This study establishes a new paradigm for photocatalytic H₂O₂ synthesis by merging dual-reaction engineering with interface-specific plasma modification and opens a scalable route toward efficient solar-driven oxidant production.