Doped titanium dioxide as a photocatalyst for UV and visible light

Author(s): Stephan P. Blöß, Lothar Elfenthal
Paper category : conference
Book title: International RILEM Symposium on Photocatalysis, Environment and Construction Materials - TDP 2007
Editor(s): P. Baglioni and L. Casssar
Print-ISBN: 978-2-35158-056-1
e-ISBN: 978-2-35158-057-8
Publisher: RILEM Publications SARL
Publication year: 2007
Pages: 31 - 38
Total Pages: 8
Language: English

Abstract: The photocatalytic properties of titanium dioxide based on the absorption of ultra violet radiation is used in many applications. Doping the crystal lattice induces changes in the band gap. This formation of interstates between the energy bands offers the possibility not only to use ultra violet light, but visible light as well. By doping the anatase phase with carbon the cut-off wavelength is shifted from 388nm (band gap 3.20eV) to 535nm (2.32eV).
Lab-scale examinations have shown that the photocatalyticaly generated radicals are able to oxidize organic derivates e.g. hydrocarbons and inorganic molecules e.g. nitrogen oxides.
Potential applications are found in the self-cleaning of surfaces and the reduction of pollution of air and water, where superhydrophilicity and high specific surface areas are acceptable.
The photocatalyst needs light and air, direct contact to pollutants (Gas, Liquid or Solid) and should be immobilized on the surface of matrices or embedded in porous, translucent structures. Efficiency of these photocatalysts is determined by reduction of testing substances such as nitrogen monoxide, isopropyl alcohol or acetaldehyde and compared with those of conventional photocatalysts.
First application is found in emulsion paints for indoor use. Tests of cements on sound insulating walls, pavements and roads are promising.

Online publication: 2011-07-01
Publication type : full_text
Public price (Euros): 0.00