Synthesis of Mfe_2O_4 (M: Cu, Mn, Co, Ni) magnetic nanoparticles and their efficient catalytic role in nitrophenol reduction

摘要

In this work, transition metal mixed ferrites (MFe_2O_4 (M: Cu, Mn, Co, Ni)) magnetic nanoparticles(MNPs) have been synthesised via co-precipitation method and annealed at 800°C. These synthesisedmetal ferrite MNPs were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM)and vibrating sample magnetometer (VSM) for their structural, surface morphological and magneticproperties, respectively. The catalytic efficiency of the synthesised ferrite MNPs was explored for thereduction of nitrophenols. Cu doped ferrite MNPs demonstrated excellent catalytic activity (morethan 90% reduction) as compared to other metal mixed ferrite MNPs which may be due to the softbehaviour of Cu and better separation efficiency of the electron-hole pairs. The kinetics of thecatalytic reaction followed pseudo first-order and the average values of the first-order rate constantfor CuFe_2O_4, MnFe_2O_4, CoFe_2O_4 and NiFe_2O_4 were observed to be 0.0031 s~(−1), 0.0013 s~(−1), 0.0011 s~(−1)and 0.0007 s~(−1), respectively. These results confirm the catalytic activities of metal ferrite MNPs in theorder of CuFe_2O_4 > MnFe_2O_4> CoFe_2O_4 > NiFe_2O_4.