Preparation and characterization of nitrogen-doped mesoporous titania with high specific surface area

Nitrogen-doped mesoporous titania aerogel photocatalysts were prepared by supercritical drying technique with carbon dioxide (SCCO₂) and calcination the urea impregnated TiO₂ aerogel at 773 K under NH₃ or N₂ + NH₃aq gaseous atmosphere. The pore properties were investigated from nitrogen adsorption measurement at 77 K. The prepared N-doped TiO₂ aerogel had a high specific surface area (116 m²/g), a total pore volume (0.33 cm³/g) and a sharp pore radius distribution (r_peak = 4.2 nm). The doping of the nitrogen atom into the TiO₂ lattice is expected from X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), and UV–Vis spectroscopy. Nitrogen states in the lattice and crystalline structure were measured using X-ray photoelectron spectroscopy and X-ray diffractometry. The N-doped TiO₂ aerogel absorbed well into the visible region up to 600 nm.