Mesoporous sulfur-doped CoFe2O4 as a new Fenton catalyst for the highly efficient pollutants removal

Herein, mesoporous sulfurized CoFe2O4 (S-CoFe2O4) was developed and applied as a new Fenton catalyst. As a result, the sulfurization for CoFe2O4 could significantly improve the Fenton performance, compared with the non-sulfurized CoFe2O4. The enhanced removal efficiencies of pollutants in Fenton process catalyzed by S-CoFe2O4 was attributed to the elevated specific area and decreased electron transfer resistance of S-CoFe2O4. The DFT calculations further confirmed that the increased charge densities of FeS bond and CoS bond could contribute to the existences of species of Fe and Co in S-CoFe2O4 with the low valence, which were more favorable to the H2O2 activation. Furthermore, electron paramagnetic resonance (EPR) tests showed that the OH and O2− were the main generated radicals during the H2O2 activation process. This work provided a new strategy for the synthesis and application of an efficient non-precious metal Fenton catalyst.