Influence of nickel dopant concentration on structural, optical, magnetic and electrochemical properties of TiO2 nanoparticle

In this work, we report enhanced photocatalytic and magnetisation effects of nickel (Ni) ion doped titanium dioxide (TiO2) nano particles. The nano crystalline TiO2 doped with different concentrations of Ni (0.05-0.2%) were prepared by sol-gel method and characterised by various analytical techniques such as X-ray diffraction (XRD), UV-Vis spectroscopy, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The Ni metal ions incorporation modified the microstructure of TiO2 nano particles considerably which are evident from XRD and SEM analyses. The band gap reduction made by the Ni impurity level extends the TiO2 optical absorption edge to visible region. The photocatalytic activity of TiO2 and Ni-TiO2 was studied by photo degradation of methyl orange dye as a function of irradiation time under visible light. The results signify that TiO2 nanoparticles doped with the higher of concentration of 0.2% Ni improves the reaction rate of hydroxyl radical production. The electrochemical behaviour of the prepared samples was analysed by cyclic voltammetry study. The existence of hard ferromagnetic behaviour with the enhanced magnetisation in Ni doped TiO2 samples make this as an appropriate material for possible applications in spintronic and magneto-electronic devices.