Atomic regulations of single atom from metal-organic framework derived carbon for advanced water treatment

Single atom (SA)-embedded nitrogen-doped carbon has shown great potential in environmental remediation. Nowadays, engineered nanomaterials (ENMs) have attracted great research interests in recent years. Metal-organic framework (MOF) derived SAs show the advantages of tunable topology and averaged separated active sites. SAs bridge the gap between homogeneous and heterogeneous catalysts. The reaction efficiency can be significantly improved by designing the MOFs derived from carbon and SAs. In this review, the research advanced in MOFs-derived carbon and SAs in advanced oxidation process (AOP) in water were summarized. Major strategies to fabricate the SAs derived from MOFs were discussed, including the mixed/single metal strategy, metal-containing linker strategy, pore confinement strategy, thermal diffusion strategy, and pyrolysis MOFs with bulk metals. Advanced characterization technologies have been introduced, including electron microscopy and spectroscopic methods. To explain the catalytic mechanism for various applications, the relationship between the performance and the atomic configuration was systematically discussed. Recent applications of the MOFs derived from carbon and SAs have been summarized. A series of the latest work on effectively removing pollutants by SAs are also listed. Based on the fundamental knowledge and recent practical application of MOFs-derived carbon and SAs, some perspectives on the further directions were presented. This review offers guidance for applying novel engineered nanomaterials in the water treatment field.