Prussian blue analogue-derived CoNi@NC core-shell microspheres for peroxymonosulfate activation toward tetracycline degradation

Prussian blue analogue (PBA)-derived carbon catalysts are promising peroxymonosulfate (PMS) activators for antibiotic wastewater purification, yet their time-dependent degradation behavior still requires further evaluation. Herein, a core-shell CoNi@NC catalyst was prepared by pyrolyzing Co Ni PBA, in which Co Ni alloy nanoparticles were confined within an N-doped carbon (NC) matrix. To evaluate the tetracycline hydrochloride (TCH) degradation behavior, a temporal knowledge graph (TKG)-assisted framework was employed as a complementary prediction tool, predicting a shift of the CoNi@NC/PMS system toward high degradation efficiency intervals. In degradation experiments, the CoNi@NC/PMS system exhibited a rapid degradation trend consistent with the prediction, achieving 73.7% TCH removal within 3 min and 91.89% within 60 min. The catalyst retained 86.74% removal efficiency after four degradation cycles, and exhibited good matrix tolerance under different pH conditions and coexisting ions. Mechanistic analysis revealed that TCH degradation proceeded through a radical/non-radical synergistic pathway, in which Co/Ni redox cycles and interfacial electron transfer promoted PMS activation. The reaction products of TCH were identified, and the toxicity assessment indicated reduced phytotoxicity of the treated solution. This work provides a useful reference for developing efficient PBA-derived catalysts for PMS-based antibiotic wastewater purification.