Effect of cobalt dopant on structural and optical properties of co-precipitated TiO2 nanopowders

Abstract

The effects of cobalt (Co) addition on structural and optical properties of TiO2 nanopowders have been investigated. A co-precipitation method was employed to synthesize TiO2 nanoparticles with various Co additives from 0-10 mol% using tetrabutyl titanate and Cobalt (II) nitrate hexahydrate as starting precursors for Ti and Co source, respectively. The crystallinity of Co-doped TiO2 nanopowders is heightened by calcination process. The crystal structure, phase formation and the corresponding functional groups of Co-doped TiO2 were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscope (SEM) was taken to observe their morphologies. The chemical compositions of Co additive into TiO2 matrix are confirmed by EDAX. Their optical properties were investigated by diffuse reflectance spectroscopy. Diffuse reflectance spectra of samples exhibit the increasing absorption in visible region with an increasing Co content. The overall characterization results indicated that the crystallinity and optical properties of TiO2 nanoparticles are significantly affected by Co dopant.