Catalytic activity of magnetic iron oxide nanoparticles for hydrogen peroxide decomposition: optimization and characterization

Abstract

Abstract BACKGROUND The present study is focused on the decomposition of hydrogen peroxide (H 2 O 2 ) using magnetic iron oxide nanoparticles (Fe 3 O 4 NPs). Intrinsic peroxidase mimicking activity of Fe 3 O 4 NPs helps in decomposition of H 2 O 2 for the generation of • OH radicals during the Fenton process. A response surface methodology based central composite design (CCD) method was adopted to optimize five different process parameters: reaction time, temperature, pH, Fe 3 O 4 NP concentration and H 2 O 2 concentration. RESULTS CCD‐predicted H 2 O 2 decomposition (%) showed close agreement with the experimental results, confirming the good fit of the experimental data to the model. A maximum H 2 O 2 decomposition of 92.31% was achieved with an initial H 2 O 2 concentration of 31.07 mg L −1 , Fe 3 O 4 NPs of 1.34 wt%, pH of 5.29, temperature of 23.1 °C and reaction time of 5.6 min as optimal values. The morphology and structure of Fe 3 O 4 NPs before and after the reaction process were characterized using scanning electron microscopy, energy‐dispersive X–ray spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy and thermogravimetric analysis. CONCLUSION The characterization data showed no significant changes in the structure of Fe 3 O 4 NPs after the reaction compared to the pristine Fe 3 O 4 NPs. The catalytic efficiency of these NPs was found to be in close agreement with other similar materials reported in previous literature. These optimization variables for H 2 O 2 decomposition using Fe 3 O 4 NPs may be useful in designing protocols for practical application at a large scale. © 2020 Society of Chemical Industry