Strongly coupled cobalt/oxygen co-doped porous g-C₃N₄ heterostructure with abundant oxygen vacancies modulated the peroxymonosulfate activation pathway

How to resist the influence of inorganic ions and limit metal release for enhanced peroxymonosulfate (PMS) activation have been always plagued by researchers. Herein, highly dispersed cobalt and oxygen co-doped porous g-C₃N₄ heterostructure (Co-O@CN) from g-C₃N₄@ZIF-67 composites was successfully fabricated, which could completely degrade ofloxacin within 20 min. Detailed characterizations reflected that the porous Co-O@CN-150 heterostructure not only endowed more active sites to be exposed but also facilitated the formation of a stable conductive structure. Besides, the synergy of abundant oxygen vacancies and Co-O-C bond accelerated the interfacial electron transfer for promoting the redox of Co²⁺/Co³⁺. Notably, Co-O@CN-150 heterostructure tuned the PMS activation pathway from radicals to non-radicals in weak acid conditions. Besides, the fabricated catalytic membrane system exhibited excellent efficiency for instantaneous degradation of ofloxacin and achieved self-cleaning performance during continuous flow-through filtration. This work could deepen the understand of the role of the covalent bond and oxygen vacancy and provided a novel tactic for practical wastewater treatment.