A review of g-C3N4-based photocatalytic materials for photocatalytic CO2 reduction

Currently, the concentration of carbon dioxide (CO₂) has exceeded 400 ppm in the atmosphere. Thus, there is an urgent need to explore CO₂ reduction and utilization technologies. Photocatalytic technology can convert CO₂ to valuable hydrocarbons (CH₄, CH₃OH, and C₂H₅OH, etc.), realizing the conversion of solar energy to chemical energy as well as solving the problems of fossil fuel shortage and global warming. Graphitic carbon nitride (g-C₃N₄), as a two-dimensional nonmetallic semiconductor material, shows great potential in the field of CO₂ photoreduction due to its moderate bandgap, easy synthesis method, low cost, and visible light response properties. This review elaborates the research progress of g-C₃N₄-based photocatalysts for photocatalytic CO₂ reduction. The modification strategies (e.g., morphology engineering, elemental doping, crystallinity modulation, cocatalyst modification, and constructing heterojunction) of g-C₃N₄-based photocatalysts for CO₂ reduction application have been discussed in detail. Finally, the challenges and development prospects of g-C₃N₄-based photocatalytic materials for CO₂ reduction are presented.