Synthesis, characterization and optical band gap of the Co2TiO4 nanoparticles

Pure Co2TiO4 nanoparticles were prepared via a sol–gel process using cobalt acetate and tetra-n-butyl titanate as Co and Ti sources and stearic acid as complexing reagent. The prepared Co2TiO4 nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and surface area analyses (Brauner–Emmett–Teller). The results indicated that the nanoparticles with particle size between 46 and 77 nm and 3.28 m2 g−1 surface area could be obtained after calcinations of the dried gel at 850 °C for 4 h. Co2TiO4 nanoparticles showed an optical band gap value of 1.3 eV and the color efficiency of the nanoparticles evaluated by colorimetric analysis resulted characteristic values of L⁎=18.60, a⁎=−0.50 and b⁎=−0.22. The samples indicated a paramagnetic behavior, as evidenced by using vibrating sample magnetometer (VSM) at room temperature.