CoFe2O4 nanoparticles supported on MCM-41 as highly efficient peroxymonosulfate catalyst for tetracycline degradation

In this study, CoFe 2 O 4 nanoparticles were anchored onto natural Opoka-derived MCM-41 (denoted as CFMCM) using a facile citrate combustion method, resulting in a composite with excellent performance and stability. Systematic characterization and peroxymonosulfate (PMS) activation experiments were conducted to evaluate tetracycline (TC) degradation performance. Compared to bare CoFe 2 O 4 , CFMCM exhibited greatly enhanced specific surface area and pore volume. The MCM-41 support facilitated multidirectional crystallization of CoFe 2 O 4 nanoparticles, resulting in reduced grain size and lower crystallinity, thereby providing abundant active sites for PMS activation. The CFMCM composite demonstrated superior PMS activation capability with a degradation rate constant that was 3.3 times higher than bare CoFe 2 O 4 . The uniform anchoring of highly dispersed CoFe 2 O 4 nanoparticles on MCM-41 effectively prevented metal leaching, ensuring excellent reusability. Radical quenching tests and electron paramagnetic resonance (EPR) analysis revealed that reactive oxygen species (•OH, SO 4 • - , and 1 O 2 ) participated in the degradation process, with SO 4 • - and 1 O 2 being the dominant species. These reactive species were generated through the redox cycling between Co 2+ /Co 3+ and Fe 2+ /Fe 3+ pairs. Furthermore, possible TC degradation pathways were proposed based on intermediates identification. This work provides new insights into developing high-efficiency PMS-activating catalysts derived from natural minerals for wastewater treatment.