Mixed-valent titanium tellurium oxides, Ti1-xTexTe3O8+x (x=0, 0.1, and 0.12): Hydrothermal synthesis, structure, and characterization

Novel mixed-valent titanium tellurium oxides, Ti1-xTexTe3O8+x (compound A, B, and C for x = 0, 0.1, and 0.12) were synthesized from TiOSO4 center dot xH(2)SO(4)center dot xH(2)O, TeO2, and H3BO3 using hydrothermal reaction conditions. The crystal structures of the materials were confirmed and refined using single-crystal X-ray diffraction. The compounds have three-dimensional framework structures consisting of TiO6 or Ti/TeO6 octahedra and asymmetric TeO4 polyhedral groups. The cell parameter of compound A, B, and C increased with the increase in the Ti - O bond distance in the TiO6 octahedron and is attributed to the increase in the Te6+ cation doping level. Detailed characterizations of the prepared materials, including Infrared, UV-visible diffuse reflectance, Raman spectra, thermogravimetric analyses, out-of-center distortion, and dipole moment calculations were performed.