Preparation of hollow silica microspheres@CoFe2O4 composite for efficient peroxymonosulfate activation

Developing small-size and high-distribution CoFe 2 O 4 nanoparticles with abundant accessible active sites is exceedingly vital for optimizing the activation efficiency of peroxymonosulfate (PMS). Herein, silica hollow (H-SiO 2 ) microspheres were employed as the carrier of CoFe 2 O 4 for decreasing its particle size and then boosting PMS activation. The introduction of H-SiO 2 microspheres alleviated the agglomeration effect of CoFe 2 O 4 , with CoFe 2 O 4 uniformly anchored on the surface of H-SiO 2 . The optimized 50-CHF exhibited excellent bisphenol A (BPA) degradation performance under the PMS system, wherein 98.9 % BPA was removed within 20 min. Given the increase of active sites and the robust active species production, BPA was more easily assembled and degraded on the surface of 50-CHF. Furthermore, quenching experiments indicated that SO 4 ∙ - ${\text{SO}}_{\text{4}}^{\bullet \text{-}}$ and 1 O 2 were the main active species for BPA degradation. This work provides new avenues for the application of H-SiO 2 microspheres and the development and application of cobalt ferrate composite catalysts.