One-step electro-synthesis of Ni2+ doped magnetite nanoparticles and study of their supercapacitive and superparamagnetic behaviors

Abstract

Application of a novel electrochemical based procedure for the preparation of the Fe3O4 nanoparticles doped with Ni2+ cations led to improvement of the magnetic and capacitive performances of the doped iron oxides in comparison with its undoped form. Electro-synthesis was employed for the preparation of both undoped and Ni2+ doped Fe3O4 nanoparticles on a stainless steel cathode under simple electrochemical conditions (i = 10 mA cm−2 and T = 25 °C and t = 30 min). Analysis of electrosynthesized samples by XRD and TEM revealed the formation of pure crystalline magnetite phase and uniform particles with size of 10 nm, and doped/undoped states were distinguished by FE-SEM and EDS analyses. The measurement of superparamagnetic characteristics of undoped Fe3O4 (Ms = 72.96 emu g−1, Mr = 0.95 emu g−1 and H Ci = 2.39 Oe) and Ni2+ doped Fe3O4 (Ms = 47.25 emu g−1, Mr = 0.22 emu g−1 and H ci = 0.78 Oe) were done using vibrating sample magnetometer. Accordingly, the doped oxide form demonstrates improved magnetic ability in comparison with the undoped state. The evaluation of charge storage capability of both doped and undoped oxide forms by cyclic voltammetry and galvanostatic charge–discharge confirmed a significant improvement in the supercapacitive performance of the iron oxide electrode doped with Ni2+ cation compared to corresponding undoped electrode.