CeO2-Cobalt Ferrite Composite as a Dual-Function Catalyst for Hydrogen Peroxide Decomposition and Organic Pollutants Degradation

This study reports the hydrothermal synthesis, characterization, and Fenton-like catalytic performance of CeO2–CoFe2O4 nanocomposites for degrading Congo Red (CR) dye and the oxytetracycline (OTC) antibiotic. A series of Ce-doped cobalt ferrite samples was prepared using a hydrothermal reaction. Additionally, the 50Ce-CFO sample was further activated with H2O2 treatment. XRD, FTIR, and SEM analyses confirmed the formation of a spinel phase alongside segregated CeO2, which acts as a grain-growth inhibitor. The increased Ce content promotes particle amorphization. FTIR showed changes in the intensity of the M–O stretching band, indicating Ce-induced bond polarization in the spinel lattice. In H2O2 decomposition tests, the 50Ce-CFO catalyst fully decomposes H2O2 in 160 min, while the activated sample completes it in 125 min. Fenton-like degradation of CR and OTC by untreated and activated 50Ce-CFO sample followed pseudo-first-order kinetics. Catalyst stability was confirmed using post-reaction XRD, FTIR, and SEM analyses. Incorporation of CeO2 into CoFe2O4 refines the crystallite size, increases the BET surface area, and enhances adsorption capacity, while the Ce4+/Ce3+ redox couple promotes reactive oxygen species generation. Owing to this dual structural and catalytic role, the CeO2-CoFe2O4 composites exhibit significantly improved Fenton-like catalytic activity, enabling the efficient degradation of organic pollutants.