Double-network hydrogel templated FeS/graphene with enhanced PMS activation performance: considering the effect of the template and iron species

Abstract

An FeS/graphene-based catalyst (DMG) was established here through a novel double-network template way for peroxymonosulfate (PMS) activation considering the effect of the template and iron species on catalysis performance. For comparison, single-network hydrogels were also used to prepare catalysts named AMG and PMG, respectively. Results proved that DMG had obvious structural improvement compared to AMG and PMG, including its lower agglomeration, higher specific surface area, higher S²⁻/SO₄²⁻ ratio, higher CC (sp²) content, more unsaturated C–O bonds and better conductivity. The double network template has been shown to provide more contact sites for the pollutant tetracycline, enable easier regeneration of Fe(II) and promote electron transport. Density functional theory (DFT) calculations revealed the effect of sulfur conversion on PMS activation. The results indicate promising applications of double-network templated catalysts for environmental remediation and provide new insights into the oxidant activation mechanism.