Metal organic frame derived CaO C supported Co composite preparation and its catalytic ozonation of triclosan

• A novel MOF-derived Co-0.55/CaO-PC-800 composite was prepared via equivalent-volume impregnation. • The catalyst achieved 90.8% triclosan removal within 6 min in catalytic ozonation. • Excellent stability was maintained with 87.3% efficiency after five consecutive cycles. Heterogeneous catalytic ozonation demands catalysts with high activity and stability, yet CaO-based catalysts suffer from hydration deactivation and poor stability, limiting their application in triclosan (TCS) degradation. A cobalt-modified calcium oxide–porous carbon composite (Co/CaO-PC) was prepared through metal-organic framework (MOF) derivatization composite coupled with an equivalent-volume impregnation method. Co/CaO-PC exhibited outstanding TCS removal performance, achieving 90.8% degradation within 6 min, and significantly higher than those of ozonation alone and other benchmark catalysts. After five consecutive reaction cycles, the catalyst still retained 87.3% of its initial activity, demonstrating excellent operational stability. Furthermore, robust performance was demonstrated in two real wastewater. •O 2 − was identified as the dominant reactive oxygen species for the degradation of triclosan (TCS). The carbon skeleton encapsulating CaO mitigated the leaching of Ca ions, while cobalt species on the surface could adsorb ozone and promote its decomposition, thus achieving a simultaneous enhancement in both catalytic activity and stability. This work provides a practical preparation strategy for modulating the activity and stability of calcium-based oxides in catalytic ozonation processes.