Carbon fiber-assisted iron carbide nanoparticles as an efficient catalyst via peroxymonosulfate activation for organic contaminant removal

Abstract

The development of efficient and environment-benign catalytic materials to activate peroxymonosulfate (PMS) for refractory pollutant removal has been considered as an attractive yet challenging topic in the field of wastewater treatment. Herein, carbon fiber-assisted iron carbide (Fe₃C@CFs) was innovatively prepared by a hydrothermal and calcination method. Fe₃C@CFs could activate PMS and remove the pollutant Acid Red 1 (AR1) up to 97.3%, and even the rate constant was 12.4 times higher than that of Fe₃C. The leaching of iron ions was only 0.002 ppm, which was extremely lower than the European standard. Furthermore, Fe₃C@CFs still exhibited a favorable catalytic performance after 4 cycles. The catalytic mechanism was investigated by a hybrid method of various radical scavengers combined with electron spin resonance, suggesting that ¹O₂ served as the main reaction oxidation species rather than ˙OH or SO₄˙⁻ during the catalytic process, different from most of the reported radical paths for activating PMS. In addition, Fe₃C@CFs possessed wide pH adaptability (3–10) and relatively low activation energy (24.47 kJ mol⁻¹) for AR1 removal. These findings pave a promising avenue to develop highly efficient and eco-friendly catalytic materials for environmental remediation.