Peroxymonosulfate activation by octahedral Cu2O for Orange Ⅰ degradation via radical and non-radical pathways

In this study, cubic Cu2O (c-Cu2O) and octahedral Cu2O (o-Cu2O) were prepared through a simple method and applied to activate peroxymonosulfate (PMS) for the degradation of Orange Ⅰ (OⅠ). o-Cu2O exhibited excellent activity for PMS activation with 85.68 % of OⅠ being removed within 30 min, and its catalytic activity remained high even if it was used repeated six times. The effects of PMS concentration, initial pH, anions (Cl–, HCO3– and NO3–) and natural organic matter (NOM) on OⅠ degradation in the o-Cu2O/PMS system were investigated. The mechanism study implied that OⅠ was oxidized via radical (SO4•–, •OH and O2•–) and non-radical (1O2 and electron transfer) pathways in the o-Cu2O/PMS system. This work provides an interesting insight into PMS activation by Cu-based catalysts for wastewater treatment.