Influence of Cu concentration on the structural, morphological, optical and catalytic properties of TiO2 thin films

Pristine titanium oxide (TiO2) and Cu doped TiO2 thin films of similar to 2.0 mu m thicknesses have been deposited on glass substrates by sol-gel dip coating technique. The deposited films are even and more adherent to the substrate. The consequences of incorporation of Cu ions of different concentration in TiO2 lattice towards the structural, morphological and optical characteristics of prepared thin films have been investigated. Cu doping alters crystallite size and morphology of doped TiO2 films marginally. Gradual increase in concentration of Cu atoms into TiO2 matrix expands the absorption window of prepared films to visible region. The decrease in excitonic energy upon Cu doping promotes the charge separation in TiO2 semiconductor. Depending upon Cu concentration, exciton life time is extended fairly which leads to improved electron-hole separation and enhanced oxidation-reduction reactions at the surface of TiO2 semiconductors. The advantage of thin film catalyst over the other catalyst structures has been exhibited by the reusability nature of Cu-TiO2 films. This study reveals that an ideal amount of Cu doping can increase the photocatalytic performance of TiO2 thin films efficiently.