Novel magnetic biochar as an activator for peroxymonosulfate to degrade bisphenol A: Emphasizing the synergistic effect between graphitized structure and CoFe2O4

Abstract The biochar loaded with CoFe2O4 nanoparticles (CoFe2O4/HPC) fabricated by pyrolysis exhibited strong magnetic property, hierarchical porous and graphitized structure. CoFe2O4/HPC showed much better bisphenol A degradation than CoFe2O4 in presence of peroxymonosulfate. The graphitized structure and the synergistic effect between graphitized structure and CoFe2O4 were found to be responsible for the superiority of CoFe2O4/HPC among all the other catalysts. The prominent role including radical way mainly contributed by SO4•– and non-radical way achieved by 1O2, and the secondary role of electron transfer way proceeded by graphitized structure were uncovered. The processes such as redox between Co(III)/Co(II) and Fe(III)/Fe(II), the reduction of Fe(III) by O2•–, and the participation of C=O in 1O2 production were significant to the excellent catalytic performance of CoFe2O4/HPC. Considering its excellent separation, stability, adaptability and reusability, CoFe2O4/HPC opened up a novel way to develop green catalyst to activate PMS for organic pollutants degradation.