We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Thermostable photocatalytically active TiO anatase nanoparticles.
- Authors
Qi, Fei; Moiseev, Anna; Deubener, Joachim; Weber, Alfred
- Abstract
natase is the low-temperature (300-550 °C) crystalline polymorph of TiO and it transforms to rutile upon heating. For applications utilizing the photocatalytic properties of nanoscale anatase at elevated temperatures (over 600 °C) the issue of phase stabilisation is of major interest. In this study, binary TiO/SiO particles were synthesized by a flame aerosol process with TiCl and SiCl as precursors. The theoretical Si/Ti ratio was varied in the range of 0.7-1.3 mol/mol. The synthesized TiO/SiO samples were heat treated at 900 and 1,000 °C for 3 h to determine the thermostability of anatase. Pyrogenic TiO P25 (from Evonik/Degussa, Germany) widely applied as photocatalyst was used as non-thermostabilized reference material for comparison of photocatalytic activity of powders. Both the non-calcinated and calcinated powders were characterized by means of XRD, TEM and BET. Photocatalytic activity was examined with dichloroacetic acid (DCA) chosen as a model compound. It was found that SiO stabilized the material retarding the collapse of catalyst surface area during calcination. The weighted anatase content of 85% remains completely unchanged even after calcination at 1,000 °C. The presence of SiO layer/bridge as spacer between TiO particles freezes the grain growth: the average crystallite size increased negligibly from 17 to 18 nm even during the calcination at 1,000 °C. Due to the stabilizing effect of SiO the titania nanoparticles calcinated at 900 and 1,000 °C show significant photocatalytic activity. Furthermore, the increase in photocatalytic activity with calcination temperature indicates that the titania surface becomes more accessible either due to intensified cracking of the SiO layer or due to enhanced transport of SiO into the necks thus releasing additional titania surface.
- Subjects
PHOTOCATALYSIS; TITANIUM dioxide; NANOPARTICLES; METALS at low temperatures; INORGANIC synthesis; METAL catalysts; X-ray diffraction
- Publication
Journal of Nanoparticle Research, 2011, Vol 13, Issue 3, p1325
- ISSN
1388-0764
- Publication type
Letter
- DOI
10.1007/s11051-010-0211-0