Superior environmentally adaptable carbon doped and Co3O4 nanoparticle modified carbon nitride materials activate PMS for rapid degradation of organic pollutants via non-radical pathways

Abstract

In this study, Co₃O₄-CN_x composites were prepared by combining solvent evaporation and calcination, using cobalt(II) acetylacetonate as the cobalt source. Carbon doping and in situ generation of Co₃O₄ nanoparticles were achieved simultaneously through calcination method. The introduction of cobalt and carbon components induced charge redistribution on the material surface, constructed novel conductive channels, and reduced interfacial charge transfer resistance, significantly enhanced electron transfer efficiency, enabling the Co₃O₄-CN₂ to exhibit excellent catalytic performance in the degradation of organic pollutants via activated peroxymonosulfate (PMS). The Co₃O₄-CN₂ + PMS system achieved 99.5 % degradation of oxytetracycline within 15 min, kinetic constants was 0.466 min⁻¹. Mechanistic analyses showed that the reaction process involves singlet oxygen, high-valent cobalt‑oxygen species, and electron transfer-mediated non-radical pathways. Co₃O₄-CN₂ + PMS system demonstrated remarkable degradation efficiency across a wide pH range (4.5–11.0) and in the presence of various inorganic anions. Additionally, the degradation rate constants for OTC in water samples from Keda lake and the Ba river water were 0.947 min⁻¹ and 1.074 min⁻¹, respectively, demonstrating the system's excellent environmental adaptability. Cycling experiments further confirmed that the system maintained stable degradation efficiency, underscoring its potential for practical application in the treatment of organic wastewater.