Effects of shock doping on the energy gap of TiO₂

In this paper, nitrogen-doped titania was achieved by detonation-driven flyer impacting on the mixtures of TiO₂ and different nitrogen precursors. XRD, UV-Vis and XPS spectra were employed to characterize the phase composition, N doping concentration and energy gap of recovered samples. N doping concentration can be effectively regulated by choosing different doping nitrogen resources, changing initial content of doping nitrogen resources and flyer velocity in order to regulate the energy gap of TiO₂. The maximum concentration of nitrogen of doped TiO₂ by shock loading at 3.37 km/s is 13.45 at%. The results show that anatase transforms to rutile and srilankite appears at a higher flyer velocity (1.9-2.52km/s), the concentration of doped nitrogen in the recovered samples increases with increasing flyer velocity, the maximum concentration of nitrogen is 13.45 at%. The edge adsorption wavelength of nitrogen-doped titania induced by shock wave is shifted from 435nm to 730 nm and the corresponding energy gap is reduced from 2.85 eV to 1.73 eV.