Synergistic Activation of H2O2 over Magnetic Fe3O4/HNT Catalyst for Rapid Remediation of NAP-Contaminated Water

Magnetic heterogeneous Fenton Fe3O4/HNT catalysts were successfully synthesized using the solvothermal method. Characterization of Fe3O4/HNT composites involved XRD, XPS, FT-IR, SEM, BET and TEM. Results showed uniform anchoring of magnetic Fe3O4 nanoparticles on HNTs’ external surface. Under pH conditions close to neutral, the catalyst achieved a naphthalene (NAP) removal efficiency exceeding 98% within 15 min while maintaining a relatively high H2O2 utilization rate. The catalyst exhibits significant resistance to common aqueous interferers containing anions (NO3−, Cl−, CO32−) and humic acids. Moreover, the catalyst could be easily isolated from the solution through the use of magnetic separation technology. It displayed remarkable stability and recyclability, maintaining NAP removal efficiency above 80% even after the fifth cycle, in comparison to the initial catalyst. The excellent catalytic performance of this catalyst is attributed to the synergistic effect between HNT and Fe3O4. Meanwhile, the diverse Fenton catalytic process of Fe3O4/HNT was explained, indicating that hydroxyl radicals (•OH) and superoxide anion radicals (•O2−) were key in eliminating NAP in the Fe3O4/HNT-H2O2 setup.