Recent Progress on Carbon Nitride and Its Hybrid Photocatalysts for CO₂ Reduction

Graphitic carbon nitride as a novel photocatalyst for CO₂ reduction reaction (CO₂RR) has attracted many recent efforts on the synthesis and modification for improving efficiency and selectivity. Herein, an overview of fundamental factors and the latest research progress of g-C₃N₄-based photocatalysts for CO₂RR is provided. The main strategies of fabrication and modification to obtain g-C₃N₄ and g-C₃N₄-based composites with high CO₂RR efficiency are summarized. Working mechanisms of each enhancement approach in terms of their effects on electronic band structures, light-harvesting capability, CO₂ adsorption capacity, separation of photogenerated electron–hole pairs etc. are explained and discussed. Finally, a brief overview on the challenges and new directions in this field is proposed.