Hemin derived iron and nitrogen-doped carbon as a novel heterogeneous electro-Fenton catalyst to efficiently degrade ciprofloxacin

Abstract

• Hemin derived iron and nitrogen-doped carbon catalyst exhibited high ciprofloxacin degradation and mineralization efficiency. • KHCO 3 -MgO dual-porogen improved the porous characteristics and exposed the iron sites. • Based on degradation intermediates analysis, a possible degradation pathway of CIP was proposed. • It exhibited good stability and potential for treatment of organic pollutants in wastewater. Heterogeneous electro-Fenton (HEF) technology has become a hot topic for degradation of organic pollutants in water. However, it remains a challenge to design effective catalysts for high H 2 O 2 utilization and pollutant degradation. In this work, we explored a novel iron and nitrogen-doped carbon catalyst derived from hemin (Fe-N-C) using KHCO 3 -MgO as dual-porogen. The results suggested that the KHCO 3 -MgO dual-porogen could not only improve the porous characteristics of catalyst, but also expose iron sites and change the proportion of nitrogen species. The pollutant degradation results demonstrated that the Fe-N-C-700/HEF system exhibited high ciprofloxacin degradation efficiency of 93.82% within 50 min and mineralization efficiency of 87.87% within 90 min by low energy consumption. Moreover, cycle experiments and metal ions leaching experiments revealed that the catalyst had good stability and recyclability. Electron spin resonance (ESR) test and radical capturing experiment showed that • OH was the dominant active species in this HEF system. In addition, the Fe-N-C-700/HEF system achieved satisfactory performance in the treatment of real water matrix, indicating the possibility for practical application in wastewater purification.