fig1

Figure 1. (A) Structure investigation of BCN@Cu/CNT by SEM characterization; (B) NO₃^- removal efficiency of BCN@Cu/CNT. This figure is quoted with permission from Zhao et al.^[46]; (C) TEM image of Cu-N-C-800; (D) The removal of NO₃^- and current efficiency using Cu-N-C-800. This figure is quoted with permission from Zhu et al.^[47]; (E) Product distribution of NITRR process using Cu SAAs as the electrocatalyst at varying potentials. This figure is quoted with permission from Li et al.^[52]; (F) FEs of NH₃ and NO₂^- using Cu-N-C-SAC at different applied potentials. This figure is quoted with permission from Yang et al.^[53].