Efficient peroxymonosulfate activation by CuO-Fe₂O₃/MXene composite for atrazine degradation: Performance, coexisting matter influence and mechanism

CuO-Fe₂O₃/MXene was fabricated using a rapid microwave hydrothermal method and used for the enhanced peroxymonosulfate (PMS) activation and atrazine (ATZ) degradation. The ATZ degradation rate could reach up to nearly 100% within 60 min at pH = 6.4, with low dosage for CuO-Fe₂O₃/5% MXene (0.1 g‧L^-1) and PMS (0.37 mM). Experimental results and DFT calculations showed that coexisting matter had little influence on ATZ degradation at low concentrations, indicating the excellent anti-interference capability of the system. Circulation and interaction of ≡Fe(III)/≡Fe(II) and ≡Cu(II)/≡Cu(I) produced SO₄^•- and •OH, O* and SO₅^•- could participate in the formation of ¹O₂. Then, ATZ degradation pathways, including dealkylation, dichlorination-hydroxylation, alkyl hydroxylation, alkyl oxidation, olefination, and deamination-hydroxylation processes, were proposed based on DFT calculations and ESI-QTOF-MS/MS data. QSAR analysis illustrated that most intermediates were more environmentally friendly than ATZ. This study developed novel materials with superior catalytic performance for elimination of refractory organic pollutants in wastewater.