fig3

Figure 3. (A) Schematic diagram of fabrication of Co-MNSs for photocatalytic CO₂RR, quoted with permission from Zuo et al.^[103]; (B) Schematic diagram of preparation of M-N-C based SACs for electrocatalytic CO₂RR, quoted with permission from Xie et al.^[104]; (C) Schematic diagram of fabrication of Cu/PCN-222, quoted with permission from Bao et al.^[105]. ZIF: Zeolitic imidazolate framework; SACs: single-atom catalysts; TCPP: tetrakis(carboxyphenyl)phthalocyanine cobalt; MNSs: metal-nitrogen supramolecular structure.