Recent Progress on Graphitic Carbon Nitride-Based Photocatalysts for Hydrogen Peroxide Synthesis

Hydrogen peroxide (H₂O₂) is an indispensable chemical that is used in many industries. Artificial photosynthesis of H₂O₂ from oxygen and water has obtained worldwide attention due to the merits of low-cost and sustainability. Graphitic carbon nitride (g-C₃N₄)-based semiconductors are one of the most popular photocatalysts for H₂O₂ synthesis due to the advanced intrinsic properties of g-C₃N₄. To realize efficient H₂O₂ photosynthesis, multiple strategies have been proposed for boosting the photocatalytic activity of g-C₃N₄. Herein, we summarize the rapid progress of H₂O₂ synthesis over g-C₃N₄-based photocatalysts in the last several years. The review begins with a brief introduction of H₂O₂ synthesis and g-C₃N₄-based photocatalysts, followed by the principle for photocatalytic H₂O₂ synthesis. Then, a series of common modification methods for preparing advanced g-C₃N₄-based photocatalysts are systematically introduced and discussed, including heteroatom doping, defect engineering, junction construction, metal cocatalyst loading, single atom loading, functionalization, and other strategies. Finally, the prospects and challenges for future development are discussed.