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

The biochar loaded with CoFe 2 O 4 nanoparticles (CoFe 2 O 4 /HPC) fabricated by pyrolysis exhibited strong magnetic property, hierarchical porous and graphitized structure. CoFe 2 O 4 /HPC showed much better bisphenol A degradation than CoFe 2 O 4 in presence of peroxymonosulfate. The graphitized structure and the synergistic effect between graphitized structure and CoFe 2 O 4 were found to be responsible for the superiority of CoFe 2 O 4 /HPC among all the other catalysts. The prominent role including radical way mainly contributed by SO 4 − and non-radical way achieved by 1 O 2 , 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 O 2 − , and the participation of C O in 1 O 2 production were significant to the excellent catalytic performance of CoFe 2 O 4 /HPC. Considering its excellent separation, stability, adaptability and reusability, CoFe 2 O 4 /HPC opened up a novel way to develop green catalyst to activate PMS for organic pollutants degradation.