Promoting Electron Transfer in Graphitic Carbon Nitride Nanosheets via Electron-Rich π–π Stacking for Efficient Visible-Light Photocatalytic Performance

Designing the surface nanostructures of graphitic carbon nitride (GCN) nanosheets is an important strategy to improve the efficient photocatalytic conversion of water to hydrogen peroxide (H2O2), but it remains a significant challenge. Herein, we designed GCN nanosheets with electron-rich flexible organic network framework structures by regulating the electron-rich triazine π–π stacking and the covalent network crossing (CNM-GCN), which effectively promotes the generation and transfer of photogenerated electrons under visible light. The melamine-formaldehyde (MF) resin, which contains electron-rich triazine rings, was used to modify the GCN nanosheets through covalent network cross-linking and supramolecular π–π stacking. The cross-linked organic framework nanostructures between nanosheets enhance their electron-donating capacity and significantly improve the separation of electrons and holes. The CNM-GCN can efficiently generate superoxide free radicals from dissolved O2 molecules under visible light and further promote the solar-driven photocatalytic conversion of O2 into hydrogen peroxide. Notably, the CNM-GCN exhibits a remarkable 10.0-fold increase in H2O2 production compared to the pristine GCN under visible-light irradiation, from 45.1 to 451.6 μmol L–1. This work contributes to the development of efficient, cost-effective nanophotocatalysts for the sustainable H2O2 production, which is of great significance for improving energy use and carbon reduction.