Preparation of TiO2 ultrafine nanopowder with large surface area and its photocatalytic activity for gaseous nitrogen oxides

✍ Scribed by Sungmin Chin; Eunseuk Park; Minsu Kim; Juyoung Jeong; Gwi-Nam Bae; Jongsoo Jurng

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 634 KB
• Volume: 206
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2010.09.035

✦ Synopsis

TiO 2 nanopowder with a large surface area and high crystallinity was synthesized by a thermal decomposition process. The physicochemical properties of the prepared powders were examined by X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption isotherms. The nanocrystallites of the prepared powers were considerably smaller than those of the commercial photocatalyst (Degussa, P25), and the particles had a dense polyhedral structure. In addition, the particles had a mainly disordered mesoporous structure with a pore volume that varied according to the pore size in the range of 2-20 nm. The photocatalytic activity of the prepared photocatalyst was obviously higher than that of P25 on the photodegradation of gaseous nitrogen oxides under UV 254+185 nm lamp irradiation. Above 40% relative humidity, the NO x removal efficiency of the prepared photocatalyst was 10% higher than that of P25. Furthermore, a suitable relative humidity and longer residence time were found to enhance the photocatalytic oxidation of gaseous nitrogen oxides by UV 254+185 nm lamp irradiation and TiO 2 nanoparticles.