Synthesis and structural characteristics of nitrogen doped TiO 2 aerogels (original) (raw)

Nitrogen doped TiO 2 aerogels were obtained by sol-gel process followed by supercritical drying with liquid CO 2 . Urea and NH 3 (25% aqueous solution) were used as nitrogen sources. The as-prepared aerogels were submitted to thermal treatments performed under different experimental conditions (temperature and heating time). Increasing the temperature from 450°C to 550°C a decrease about 32% and 15.4% of the particle size and surface OH groups' concentration, respectively and an increase about 21.4% of the incorporated nitrogen in TiO 2 lattice were observed. The immersion of the TiO 2 aerogels in NH 3 solution induced a decreasing by 48.86% and by 80% of the S BET and the aerogel porosity, respectively. The photocatalytic activity of the obtained N-doped TiO 2 was found to depend mainly on the nitrogen incorporation in the TiO 2 lattice.