Formation of Palladium (II) Oxide within Titanium Dioxide Electrospun Nanofibers: Combined Raman and X-ray Diffraction Study

TiO$_{\mathrm{2}}$-PdO composite submicron fibers were produced using electrospinning method. The morphology of the fibers was probed using Scanning Electron Microscopy, whereas Raman Spectroscopy and powder X-Ray Diffraction experiments were used for probing the crystalline phases of pure TiO$_{\mathrm{2}}$ and TiO$_{\mathrm{2}}$ -- PdO fibers. In particular, the effects of annealing time (at 600 $^{\mathrm{o}}$C) on the crystal structure and the role of embedded PdO were investigated. The results of Raman scattering measurements have shown dominant anatase TiO$_{\mathrm{2}}$ phase in all samples. The crystallinity of anatase phase, as well as the appearence of rutile and brookite$_{\mathrm{\thinspace }}$phases, depend on annealing and doping conditions. The existence of PdO within TiO$_{\mathrm{2}}$ stabilizes its anatase phase, and the Raman modes ascribed to PdO become more pronounced with annealing. The combination of Raman and X-Ray diffraction techniques proves to be a powerful tool in characterizing these materials.