Ginkgo leaf-derived Co3O4/N-doped biochar for enhanced rapid degradation of tetracycline in water via peroxymonosulfate activation

The contamination of aqueous environments by antibiotics necessitates efficient remediation strategies, among which cobalt-based advanced oxidation processes (AOPs) have garnered significant attention for their high degradation efficiency. Herein, we utilized N self-doped biochar (SDBC) with a high specific surface area derived from Ginkgo biloba leaves as a support for the in-situ growth of Co 3 O 4 nanoparticles via one-pot pyrolysis. The optimized Co 3 O 4 /N-SDBC-800 catalyst exhibited outstanding activity for tetracycline (TC) degradation through peroxymonosulfate (PMS) activation, achieving a remarkable 98.47% removal efficiency within 5 min. The corresponding rate constant was 0.241 min −1 , surpassing most previously reported values. Moreover, the Co 3 O 4 /N-SDBC-800/PMS system displayed robust performance over a wide pH range (maintaining >90% TC removal efficiency from pH 3–11) and exceptional operational versatility in diverse aqueous matrices. Mechanistically, the degradation pathway was revealed to be predominantly governed by non-radical processes, as evidenced by radical quenching experiments and electron paramagnetic resonance (EPR) analysis. Singlet oxygen ( 1 O 2 ) was identified as the principal reactive species responsible for the catalytic oxidation of the organic pollutants. The synergistic coupling of heteroatom N-doping and graphitization was found to create active sites and reconfigure the electronic structure, thereby facilitating charge transfer and ultimately accelerating the decomposition of TC.