Silver-Doping Induced Lattice Distortion in TiO₂ Nanoparticles

The Ag-doping effects on TiO₂ nanoparticles are investigated by means of x-ray diffraction (XRD) and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO₂. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the c/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1% Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interfacial interaction between the anatase and rutile phases induced by different Ag concentrations.