Sol-gel auto-combustion synthesis of Cu1-xMgxFe2O4 nanoparticles and their heterogenous Fenton-like activity towards tartrazine

Abstract

In this study, magnesium/copper ferrite nanoparticles Cu1-xMgxFe2O4 with composition (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by sol–gel auto-combustion method. Samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). Subsequently, the nanoparticles were investigated as heterogeneous Fenton-like catalysts for tartrazine degradation in aqueous solution. Effects of experimental conditions of pH, tartrazine concentration, catalyst loading, H2O2 concentration and temperature were studied in detail. The catalytic activity of all Cu1-xMgxFe2O4 nanoparticles was compared at identical operational conditions. Among all the samples, Cu0.2Mg0.8Fe2O4 exhibited high catalytic activity, great stability and easily recyclable compared of pure CuFe2O4, MgFe2O4 and other Cu1-xMgxFe2O4 samples. Results indicated that 94.6 % of tartrazine was efficiently degraded by 0.2 g/L Cu0.2Mg0.8Fe2O4 with 239.9 mg/L H2O2 at pH = 3 and 30 °C during 120 min. Magnesium substitution enhanced the catalytic activity of copper ferrite (CuFe2O4) as the removal rate increased with an increase in magnesium content. Based on the experimental results, possible mechanism for the degradation of tartrazine was proposed. Hence, magnesium-copper ferrite can be used as effective catalysts for the destructive removal of organic pollutants in wastewater.