Nitrogen-doped TiO2/Graphene Composites Synthesized via the Vapour-thermal Method

TiO 2 /graphene composite was synthesized in the vapor environment of isopropanol. In order to improve the properties of composite, N-doped of TiO 2 /graphene with different N/Ti molar ratio was prepared in the vapor environment of deionized water and used urea as the source of nitrogen. The N-doped occupies in the interstitial sites of TiO 2 lattice, substitutes for O element in TiO 2 and for C element in graphene, and simultaneously changes the chemical states of Ti and O elements in TiO 2 . N-doped changes the morphology of TiO 2 from nano-sheets to nanoparticles, accompanying with the decrease in specific surface area of the composites, first increases the particle size of TiO 2 and then decreases, and alters the vibration modes of Ti-O-Ti. The composite with R N/Ti =2 exhibits the enhanced photocatalytic degradation performance to methylene blue, and the degradation rate increases from 7.7×10 −2 min −1 for the undoped composite to 9.6×10 −2 min −1 .