Efficient activation of peroxymonosulfate for tylosin degradation by multiple charge carriers of Co/Co3O4/CN@g-C3N4

A Co 3 O 4 /g-C 3 N 4 p-n heterojunction photocatalyst was fabricated by coupling ZIF-67-derived 3D porous Co/Co 3 O 4 /CN (N-doped carbon) composites with crystalline g-C 3 N 4 nanosheets for activating peroxymonosulfate (PMS) towards tylosin (TYL) degradation. The catalyst was synthesized via a carbonization-oxidation strategy, which retained the dodecahedral framework of ZIF-67 and simultaneously formed intimate interfacial contact with g-C 3 N 4 , thereby facilitating efficient interfacial charge transfer. The constructed p-n heterojunction generated an internal electric field that promoted migration of photogenerated electrons and holes and suppressed charge recombination, thereby improving photocatalytic performance. Moreover, the localized surface plasmon resonance (LSPR) effect of metallic Co induced the generation of energetic hot electrons and hot holes under visible light, accelerating PMS activation and enhancing the Co(II)/Co(III) redox cycle. The synergistic interaction between photogenerated charge carriers and LSPR-induced hot carriers significantly promoted PMS activation, driving the generation of primary reactive oxygen species (·O 2 - and 1 O 2 ) and achieving 95.4% TYL degradation within 16 min. Toxicity and molecular docking analyses confirmed reduced antibacterial activity of degradation products. This study highlights the dual contributions of heterojunction-driven charge separation and LSPR-induced generation of hot carrier with subsequent interfacial transfer in achieving efficient, sustainable antibiotic degradation.