Efficient peroxymonosulfate activation by Zn/Fe metal-organic framework-derived ZnO/Fe3 O4 @carbon spheres for the degradation of Acid Orange 7.

ZnO/Fe3 O4 @carbon spheres, which synthesized via a calcination process used Zn/Fe metal-organic frameworks (Zn/Fe-MOFs) as a precursor, were studied for the activation of peroxymonosulfate (PMS) for the degradation of Acid Orange 7 (AO7). The ZnO/Fe3 O4 @carbon spheres exhibited relatively high catalytic degradation properties for AO7 in an aqueous solution. The AO7 degradation reached 93.6% in 15 min under the conditions: 0.20 g/L ZnO/Fe3 O4 @carbon spheres, 1.25 mmol/L PMS, 0.03 mmol/L AO7, and initial pH of 4. Findings revealed that higher ZnO/Fe3 O4 @carbon spheres dose and PMS concentration, lower initial AO7 concentration, and acidic pH favored the AO7 degradation to a certain extent. The mechanisms for the activation of PMS by ZnO/Fe3 O4 @carbon spheres were proposed based on the results of radical identification tests and structure characterization. Both radical and nonradical pathways contribute to the AO7 degradation in this system. PRACTITIONER POINTS: PMS + ZnO/Fe3 O4 @carbon spheres system can effectively catalyze PMS to decompose AO7. Both radical and nonradical pathways contribute to the degradation of AO7 in this system. The acidic condition was favorable for the activation of PMS.