Fe containing template derived atomic Fe–N–C to boost Fenton-like reaction and charge migration analysis on highly active Fe–N4 sites

Abstract

Persulfate-based advanced oxidation processes are promising technologies to solve water pollution. In this work, single iron atoms are anchored on three-dimensional N-doped carbon nanosheets by a chemical vapor deposition (CVD) method with ferrocene-loaded CaO as the hard template. The high surface density of Fe–N₄ sites and abundant interconnected meso–macro pores are highly favorable for activating peroxymonosulfate (PMS) to produce superoxide radicals (O₂˙⁻), giving rise to ultrahigh activity and excellent stability for pollutant degradation. Experiment and density functional theory (DFT) calculations reveal that Fe–N₄ is the main active site, on which electrons transfer from C to Fe via the C–N–Fe bond to secure the low-valence state of Fe species for the redox process. This work proposes a new strategy for developing highly active single-atom materials by CVD and reveals mechanisms of PMS activation on single-atom activators.