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

Abstract

TiO₂/graphene composite was synthesized in the vapor environment of isopropanol. In order to improve the properties of composite, N-doped of TiO₂/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 TiO₂ lattice, substitutes for O element in TiO₂ and for C element in graphene, and simultaneously changes the chemical states of Ti and O elements in TiO₂. N-doped changes the morphology of TiO₂ from nano-sheets to nanoparticles, accompanying with the decrease in specific surface area of the composites, first increases the particle size of TiO₂ 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.

Keywords

TiO₂/graphene / vapor-thermal / nitrogen-doped / photocatalytic performance