Enhanced peroxymonosulfate photoactivation by nitrogen-doped multiwalled carbon nanotube-loaded CoFe2O4 for orange G degradation: Performance, mineralization and reaction mechanism.

In this study, CF@N-MWCNT nanocomposites were successfully synthesized by anchoring cobalt ferrite (CoFe2O4, CF) on nitrogen-doped multiwalled carbon nanotube (N-MWCNT) and used to promote ultraviolet (UV) light-induced peroxymonosulfate (PMS) activation for the removal of the azo dye orange G (OG).The incorporation of N-MWCNT enhances the catalytic performance and photocatalytic activity of CF. A prominent synergistic effect on the removal of OG by UV irradiation, CF@N-MWCNT, and PMS was evident through comparisons of various reaction systems. Almost complete degradation (99.5%) of OG was achieved within 30 min at [OG]0 = 50 mg/L, [PMS]0 = 1 mM, CF@N-MWCNT = 0.1 g/L under pH = 7. Scavenging experiments indicated that non-radical pathways played a significant role in OG degradation apart from the contribution of hydroxyl radical (HO•) and sulfate radical (). The catalyst demonstrated superior catalytic performance across a broad pH range (3-11) while exhibiting strong resistance to interference from coexisting substances in aqueous environments. Furthermore, the UV/CF@N-MWCNT/PMS system can effectively remove numerous recalcitrant pollutants from dyeing wastewater. Overall, this study highlights the promising catalytic performance of the CF@N-MWCNT nanocomposite for UV-activated PMS, offering a potentially effective method for treating dyeing wastewater.