Electrical properties of TiO2/CO3O4 core/shell nanoparticles synthesized by sol-gel method

Abstract

TiO2/Co3O4 core-shell nanoparticles were successfully synthesized by the sol-gel method in two steps: the first step is the sol-gel synthesis of Co3O4 nanoparticles, and the second step is the synthesis of TiO2/Co3O4 nanoparticles by sol-gel method. The obtained Co3O4 and TiO2/Co3O4 core-shell nanoparticles were investigated utilizing X-ray diffraction, scanning electron microscopy, Fourier transforms infrared spectroscopy, diffuse reflectance spectroscopy, and conductivity measurement. X-ray diffraction analysis showed the presence of both Co3O4 and TiO2 phases in TiO2/Co3O4 core-shell nanoparticles; co3o4 nanoparticles have a cubic shape, and TiO2 nanoparticles have a tetragonal shape. SEM images of Co3O4 nanoparticles show most of the particles are smoothly distributed, having separate boundaries, and images of TiO2/Co3O4 nanoparticles showed that with an increase in calcination temperature, the size of the core-shell nanoparticles also increases. FTIR spectrum of both confirms the synthesis of Co3O4 and TiO2/Co3O4 nanomaterials. Diffuse reflectance spectroscopy exhibited the band gaps of TiO2/Co3O4 core-shell nanoparticles decrease with the increase of the temperature. The conductivity of the TiO2/Co3O4 core-shell nanomaterials increases with an increase in temperature and also with an increase in frequency.