Mesoporous Carbon@ZnCuFeS nanoparticles for photocatalytic degradation of organic pollutants via peroxymonosulfate activation

Various activation mechanisms have been developed for peroxymonosulfate (PMS), an oxidant that is extensively employed in sulfate radical-based advanced oxidation processes for the elimination of organic contaminants from water. Visible-light-assisted PMS activation presents significant potential for pollution remediation. This study generated Carbon@ZnCuFeS nanoparticles (NPs) via hydrothermal processing and employed them to activate PMS under visible light, resulting in effective pollutant degradation. NPs enabled a synergistic interaction between photocatalysis and PMS activation, with the NPs/Light/PMS combination exhibiting efficacy across a broad pH spectrum, especially in neutral and slightly acidic environments. The reaction rate follows a pseudo-first-order (PFO) kinetic model, with rate constants (0.1056 min⁻¹) varying across systems, highlighting the superior efficiency of the light/NPs/PMS system in accelerating RhB degradation (95.8 %). The radical quenching tests identified SO₄^•‒ and ^•OH as reactive species, with h^⁺, ¹O₂, and ^•O₂⁻ as the primary contributors to pollutant degradation. The ^•O₂⁻ produced further activated PMS, generating more ^•OH via interactions involving SO₄^•‒ and H₂O/OH⁻. RhB degradation is most efficient at neutral pH, with modest decreases in acidic settings due to H^⁺ interference and considerable drops in alkaline surroundings due to charge repulsion and PMS deactivation. The system demonstrated remarkable reusability; nevertheless, degradation efficiency and reaction speeds diminished at elevated RhB concentrations. The efficacy of the NPs/Light/PMS system was assessed across several water types and contaminants, yielding significant insights into the mechanics of visible-light-assisted PMS activation and endorsing an environmentally sustainable approach for the degradation of organic pollutants.