Regulating electron region of iron phthalocyanine by defective graphene enhances peroxymonosulfate activation for bisphenol A degradation

Abstract

Fe-based carbonaceous materials are a promising catalyst for the degradation of organic pollutants in wastewater through the advanced oxidation. The electron density of Fe centers plays significant role on their degradation performance. However, how to tune the electronic structure of Fe centers to boost catalytic activity is a huge challenge. Herein, FePc/DG hybrid (FePc: iron phthalocyanine; DG: defective graphene) was designed to degrade bisphenol A (BPA). In FePc/DG hybrid, defects with localized regions can transfer electrons to Fe sites, forming electron-rich Fe sites, which is beneficial to boost BPA degradation. As expected, FePc/DG hybrid can efficiently activate the peroxymonosulfate (PMS) and completely remove BPA within 10 min. Meanwhile, FePc/DG hybrid can effectively degrade BPA with an excellent resistance to background interference (pH, ions, and water matrixes) as well as prominent cycle stability (completely remove BPA after five cycles). Density functional theory results demonstrate that FePc/DG hybrid has high adsorption energy for PMS and maximum electron transfer to PMS, which promotes O-O bond cleavage of PMS and boosts BPA degradation. This study further explores the potential of Fe-based materials in degrading pollutants and demonstrates the effect of the electrons around active site on PMS activation.