Cu₂O/CuO induced non-radical/radical pathway toward highly efficient peroxymonosulfate activation

The synergistic mechanism of free radical non-radical catalytic pathways, as a pivotal step for effective degradation of organic pollutants, has been widely concerned. A novel Cu₂O/CuO was prepared to efficiently catalyze peroxymonosulfate (PMS) to degrade organic pollutants in the free radical/non-radical pathway, showing excellent catalytic activity and high stability. The Cu₂O/CuO-PMS was endowed with great adaptability over a wide pH range (pH 3–11) and varies inorganic anions (SO₄²⁻, NO₃⁻, HCO₃⁻ and Cl⁻) for degradation of Bisphenol A (BPA). The experiments and characterization analyses demonstrated that free radicals (^·OH, SO₄^·-) and non-free radicals (Cu(III), ¹O₂, surface complexes) were the active species and the synergistic catalytic mechanism associated with Cu(III)/Cu(Ⅱ)/Cu(I) redox cycles. In addition, based on the UPLC/MS results and toxicity assessment data, a possible degradation pathway for BPA was proposed, and it also showed that the system could degrade the contaminants to less toxic or harmless small molecules. The results of this work show the notable potential of Cu₂O/CuO activating PMS to degrade organic pollutants in complex aqueous environments.