Oxygen vacancy-mediated dispersion of MnOx on Co3O4 for enhanced Fenton-type degradation of tetracycline.

Developing efficient and stable heterogeneous Fenton-like catalysts is essential for advancing the practical application of wastewater remediation. In this study, a ZIF-67-derived Co3O4 catalyst decorated with highly dispersed MnOx ​was synthesized for the degradation of tetracycline (TC). Compared to commercial Co3O4, the ZIF-67-derived Co3O4 nanoflakes provide abundant surface oxygen vacancies that serve as anchoring sites to facilitate the high dispersion of MnOx ​and promote the enrichment of Mn2+species. These Mn2+ sites effectively activate hydrogen peroxide to generate hydroxyl radicals (⋅OH) for TC degradation. Under optimized conditions, the 5%MnOx/Co3O4​ system achieved ∼90.0% TC removal within 80 min with a reaction rate constant of 0.029 min-1, significantly outperforming ZIF-67-derived Co3O4 ​(0.004 min-1) and MnOx/Commercial Co3O4 (0.013 min-1). Radical quenching experiments identified ⋅OH as the primary reactive species. The catalyst also exhibited excellent reusability and stability, offering a strategic approach for designing high-performance transition metal catalysts through support-mediated active site optimization.