Atomic-level coordination structures meet graphitic carbon nitride (g-C3N4) for photocatalysis: Energy conversion and environmental remediation

Up to date, the single-atom catalysts (SACs) have provided a sustainable solution for mitigating the energy crisis and improving environmental quality. The enhanced efficiency and selectivity in various chemical reactions relies on the rational design of metal atom coordination environments and a deep understanding of the underlying mechanisms. The atomic-level coordination between metal species and graphitic carbon nitride (g-C3N4) support offers potential unique characteristics and advantages. This review summarizes and provides insights into the recent progress of g-C3N4-based SACs. We discuss the principles and benefits of introducing atomic-level metal sites on g-C3N4, as well as essential preparation methods and characterization techniques. We also explore the applications of g-C3N4-based SACs in photocatalytic energy conversion and environmental remediation to gain a comprehensive understanding of how single-metal sites impact activity, selectivity, and stability. Finally, we highlight both the opportunities and challenges for development of g-C3N4-based SACs in the future.