Facile synthesis of porous Fe-doped g-C3N4 with highly dispersed Fe sites as robust catalysts for dinitro butyl phenol degradation by peroxymonosulfate activation

Abstract

In this work, a series of porous Fe-doped g-C 3 N 4 (Fe-CN) were facilely synthesized by a solid state grinding method followed by heat treatment process with the aid of thiourea as a pore-forming agent and auxiliary dispersant of Fe, aiming to construct efficient catalysts for 2- sec -butyl-4,6-dinitrophenol (DNBP) degradation via peroxymonosulfate (PMS) activation. The feature of this synthesis method is the easy creation of heterogeneous catalysts with highly dispersed metal sites anchored in porous architecture of g-C 3 N 4 under solvent-free conditions. The as-prepared catalysts were characterized by various techniques, such as XRD, FT-IR, XPS, HRTEM, and BET measurements. Fe was found to be coordinated with the N atoms in the skeleton of g-C 3 N 4 . Fe-CN exhibited promoted catalytic activities in PMS activation for oxidative degradation of DNBP compared to pristine g-C 3 N 4 with the highest DNBP degradation efficiency at 12.5%Fe-CN under the optimal conditions with long-term structural stability characteristics. It was demonstrated that the reactive oxygen species including SO 4 •− , •OH and Fe IV =O exerted contribution on DNBP degradation via both radical and non-radical mechanisms, but a more contribution of Fe IV =O was observed. A reasonable catalytic mechanism and degradation pathways of DNBP in the 12.5%Fe-CN/PMS system were proposed. This study puts forward an innovative strategy for the design and development of promising heterogeneous Fe-CN catalysts for PMS-based wastewater treatment. • The porous Fe-doped g-C 3 N 4 (Fe-CN) was prepared via a solid phase grinding method. • Thiourea helps to form the porous structure with highly dispersed active sites. • The highest DNBP degradation efficiency was achieved in the 12.5%Fe-CN/PMS system. • Fe-CN showed long-term structural stability for PMS activation. • PMS activation mechanism and DNBP degradation pathway were proposed.