Photocatalytic degradation of rhodamine B on building materials – influence of substrate and environment

Author(s): D. Stephan, P. Wilhelm, M. Schmidt
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: 299 - 306
Total Pages: 8
Language: English

Abstract: In the last decade there has been a strong push to develop innovative building materials that offer extra value in addition to outstanding mechanical properties and workability.
Modern materials based on TiO2-photocatalysis make it possible to improve the climate, and thereby to contribute to personal well-being and environmental protection at a time where the environmental and the health awareness of the population have increased sharply.
Considering titania photocatalysis, relative humidity and pH play an essential role in forming the reactive radicals. Even if only human comfort concentrations are considered, the ambient water vapor concentration can vary considerably. In addition the pH of TiO2- containing systems can differ in a wide range and might have a serious effect on the photocatalytic properties.
In order to investigate the influence of the substrate and the climate on the photocatalytic performance, a model-system is needed. Rhodamine B has found to be a good organic molecule to simulate the degradation of organic pollutants. In the absence of TiO2, rhodamine B is quite resistant towards UV light. By means of UV-vis spectroscopy and measurement of total organic carbon (TOC) in solution, it has been shown, that rhodamine B is not only decolorized, but totally decomposed by UV light in the presence of TiO2.
In the present study ceramic specimens were covered with a transparent layer of a TiO2-sol (particle size ~10 nm). Tests were performed with different TiO2 concentrations and different inorganic materials to vary the pH. The photocatalytic performance was tested by the degradation of rhodamine B, which was measured by colour measurement on the surface.

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