Structural and optical studies of TiO₂:Ag₂O nanocomposite by sol-gel method

As TiO₂ is suitable for electronic and electrical applications, in the present work the authors have successfully modified TiO₂ by adding silver (Ag) to form titanium oxide-silver oxide (TiO₂:Ag₂O) nanocomposite samples by using sol-gel technique. Characterizations of these composites have been performed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-Vis spectroscopy. XRD study revealed that the crystal structure of the samples consisted of tetragonal and cubic phases. This study further showed an increment in the average crystallite size from 8 nm to 38 nm with an increase in Ag concentration. The increase in crystallite size has been confirmed additionally by SEM and AFM. The increment in the average particle size of the samples may be attributed to an increase in silver molarity in the TiO₂ matrix. Significant red shift in the absorption edge has been observed, causing reduction in the energy bandgap of the composites from 3.89 eV to 3.46 eV with an increase in particle size which is evident from UV-Vis spectroscopic studies. This wide-band gap properties of the TiO₂:Ag₂O nanocomposite make it suitable for memory-storage devices and dielectric applications.