Magnetic Catalyzed Fenton Oxidation by CuO/ns-Fe3O4 for Modification of Humic Acids

Humic acids (HAs) are widely used as adsorbents or carriers, yet they still lack oxygenic functional groups under certain conditions. Modification via catalytic oxidation under mild conditions is an ideal method to increase the oxygenic functional groups in HAs—if simple catalyst separation could be realized. Here, we report the use of CuO nanoparticles supported by Fe3O4 magnetic nanospheres as magnetic catalytic systems (MCSs) that could catalyze HA modification via Fenton oxidation. These MCSs can be easily magnetically separated from the products. The content of carboxyl groups increased from 2.45% to 10.47% after reaction, while the yield of modified HAs remained approximately 100%. These results indicate that oxidation with MCSs could be a potential method for HA modification.