Evolution of microstructure and optical properties of TiO2/Au nanocomposite

Abstract

TiO₂/Au nanocomposite has been synthesized by mixing Au with milled TiO₂ nanopowder through wet chemical route. The effect of Au on the microstructural and optical properties of TiO₂ nanopowder has been studied by XRD, FESEM, UV Visible, PL and FTIR techniques. Our study indicates that Au causes the decrease of crystallite size of TiO₂ by accumulating on the circumference of these nanoparticles. TiO₂/Au nanocomposite exhibits strong spectral response in the visible range due to the surface plasmon effect. Band gap of TiO₂ nanopowder reduces from 3.4 eV to 3.1 eV while making composite with Au. The PL spectra showed that emission peak intensity of TiO₂ nanopowder decreases in the presence of Au. The reductions in band gap and electron-hole recombination in TiO₂/Au nanocomposite suggest that TiO₂/Au could be a good candidate for photocatalysis.