Improvement Catalytic Efficiency of the Fenton-Like Reaction via the Interaction among Fe Species Encapsulated in N-Doped Carbon Materials

The Fenton-like reaction has been widely used for environmental modification. However, improvement of the catalytic efficiency is still a challenge. In this study, a series of core-shell-shaped catalysts (FeNC-<i>x</i>, <i>x</i> presents the calcination temperature) for the Fenton-like reaction was fabricated through the pyrolysis of the Fe-based metal-organic frameworks (Fe-MOF). The Fe species were encapsulated by the N-doped carbon materials and changed from Fe₃O₄ to Fe₃C, α-Fe, and Fe-N₄ with the temperature increasing from 500 to 800 °C. Simultaneously, the electron density of the Fe atom obviously increased. FeNC-650 exhibited high efficiency, as more than 85.6% TC (40 mg/L) instantaneous removal through the H₂O₂-based Fenton-like reaction. The turnover number is about 70 and 64 times higher than that of Fe-MOF and FeNC-500. The synergistic interaction among Fe₃C, α-Fe, and Fe-N₄ induced electron distribution around the Fe atom and excellent catalytic performances. Moreover, FeNC-650 exhibited excellent interference resistance toward different anions and humic acid. The toxicity of intermediate products decreased during the TC degradation. This research may give a strategy for the synthesis of catalysts used in wastewater purification.