Characterization of nanocrystalline cobalt doped TiO_2 sol-gel material

摘要

Nanocrystalline 1%, 2% and 4% Cobalt-doped TiO_2 were prepared by sol-gel technique, followed by freeze-drying treatment at -30℃ temperature for 12 h. The obtained gels were thermally treated at 200,400,600 and 800 ℃. X-ray Powder Diffraction (XRD), Scanning Electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX) were used to study its structural properties. The XRD pattern shows the coexistence of anatase phase and minor brookite phase. UV-vis Spectroscopy and Photoluminescence (PL) were used to study its optical properties. Optical band gap was calculated with the incorporation of different concentrations of cobalt. UV-visible spectroscopy shows variation in band gap for the sample treated at different temperatures for same concentration. All Cobalt doped TiO_2 nanostructures show an appearance of Red shift relative to the bulk TiO_2. The determination of magnetic properties was also carried out by Gouy balance method.