Heterogeneous Fe-Ni dual-atom catalysts coupled N-vacancy engineering for enhanced activation of peroxymonosulfate

The integration of nitrogen vacancies (Nv) exhibits significant role in promoting the efficiency of single-atom catalysts (SACs). Herein, a novel dual SAC, FeNi-Nv/CN, was developed via immobilizing Fe-Ni dual atoms onto graphitic carbon nitride with Nv sites. The FeNi-Nv/CN could effectively activate peroxymonosulfate (PMS) and generate plentiful reactive oxygen owing to the excellent Fenton-like catalytic property of FeNi, which could facilitate the degradation of Orange II. Moreover, the Nv in FeNi-Nv/CN could augment electron density around Fe-Ni atomic pairs obviously, which was beneficial to strengthen the electron transfer process (ETP) and further improve the degradation efficiency of Orange II. The density functional theory (DFT) calculations and experimental results of FeNi-Nv/CN testified the robust synergistic capacity between dual single-atomic reaction sites and Nv. This work provided a valuable strategy for the construction of dual SAC and could be a promising candidate in the effective degradation of environmental contaminant.