Cu₂O-modified magnetic iron-nitrogen co-doped biochar effective peroxymonosulfate activation for degradation of...

In water treatment, peroxymonosulfate (PMS) systems which involve both radical and non-radical degradation mechanisms, offer a promising approach due to their green and cost-effective nature. In this study, a magnetic Cu₂O-modified iron-nitrogen co-doped biochar catalyst (Cu₂O/Fe-N-BC) was successfully synthesized from coffee grounds via a combined calcination-chemical co-precipitation approach, and its catalytic performance for peroxymonosulfate (PMS) activation to remove Diethyl Phthalate (DEP) was systematically evaluated. The system exhibited an impressive DEP removal rate of 98% within 60 min under neutral pH conditions (pH 7.0), with singlet oxygen (¹O₂) playing a significant role in the degradation process. The presence of Fe facilitated PMS activation, generating reactive oxygen species, while also improving the catalyst's recyclability and reusability, owing to its magnetic characteristics. Nitrogen doping within the biochar enhanced electron transfer, modified the morphology and defect structure of the carbon matrix, and substantially boosted the catalyst's catalytic activity. The interaction between copper and iron ions facilitated the redox cycling of Fe (II)/Fe (III) and Cu (I)/Cu (II), thereby improving electron transfer across the catalyst surface and promoting the generation of free radicals. The Cu₂O/Fe-N-BC/PMS system demonstrated excellent stability and reusability, offering a promising approach for the treatment of wastewater contaminated with organic pollutants. This system operates efficiently under neutral conditions, is energy-effective, and addresses limitations commonly encountered with traditional Fenton reactions.