Correlation between crystal structure and thermal reaction of TiO2 - Graphene Oxide

Abstract

TiO2 - Graphene oxide (GO) (GO = 0-1.0wt %) powders were synthesised using sol-gel method and annealed at 500°C. The samples were then characterised using X-ray diffraction (XRD). The additional of GO gave significant influence on the crystal structure of TiO2. The lattice parameter of TiO2 were increased with decreasing GO concentration. The unit cell volume of TiO2-GO annealed in N2 decreased with the oxygen occupancy. In contrary, the TiO2-GO annealed in O2 has an increase in O2 occupancies in the lattice that was nearly proportional to its unit cell volume. A continuous weight loss was recorded by TGA at a temperature range of T= 30 - 1000°C that were associated with H2O, C-H and C-O species. It is concluded that the Ti-O-C and Ti-C bonds were formed for samples annealed in O2 and N2 respectively. The weight loss of TiO2-GO annealed in O2 is lesser than that annealed in N2 for same concentration additional GO into TiO2.