Structural, optical, and magnetic study of Ni-doped TiO2 nanoparticles synthesized by sol-gel method

In this research, the effects of transition metal (Ni) doping to metal-oxide nanoparticles (TiO2) were studied. Various weight ratios (5, 10, 15, and 20%) of Ni-to-TiO2 nanoparticles were synthesized using the sol-gel technique. These doped nanoparticles were prepared using titanium butoxide and nickel nitrate as precursors and methanol as a solvent. The effects of Ni doping to TiO2 were examined using a variety of characterization techniques, X-ray diffraction (XRD), Fourier-transform-infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, field-emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM). The XRD reveals that the Ni-doped TiO2 crystallizes in a tetragonal structure with anatase phase. The particle size and lattice strain were calculated by Williamson-Hall equation. The presence of strong chemical bonding and functional groups at the interface of TiO2 nanoparticles was confirmed by FTIR. The optical properties of undoped and doped samples were recorded by UV-Vis spectroscopy. The saturation magnetization (M (s)) was found higher for undoped as compared to doped samples. The surface morphology and the element structure of the Ni-doped TiO2 nanoparticles were examined by FESEM.