The effect was shown by Fujishima and Honda in 1972 and occurs in the presence of titania, water and uv radiation. It leads to the degradation of pollutants and may be for example applied to the formation of self-cleaning surfaces.
Titania can be used in construction materials
like bricks or tiles, or as self-cleaning facade color.
http://www.abc.net.au/science/articles/2006/01/23/1551954.htm
Sorry, only available in German.
http://www.dradio.de/dlf/sendungen/forschak/1622791/
http://idw-online.de/pages/de/news486232
http://www.wissenschaft.de/wissenschaft/news/237626.html
http://www.pro-physik.de/details/news/prophy13176news/news.html
But TiO2 can also be used for hydrogen production.
http://phys.org/news/2012-03-method-yields-highly-reactive-hydroxylated.html
http://pubs.acs.org/doi/abs/10.1021/nl051807y
Regards,
Joachim
Vielen Dank Herr Pimskern für die interessante Beispiele der Anwendungen.
Back in English, the examples are mainly paints or more precise fine particles includes in paints. Do you know some examples of thermal spray or PVD coatings industrial applications?
a high catalytic activity of TiO2 is usually observed on nanoparticles so no mystery you find it as very fine powder. I am aware of some plasma spray tests using mixed powder (containing TiO2) but they are definitely not commercial (yet). The size of the particles in the splats was way too large to be useful. For sure I would not use PVD for a photocatalyst.. the surface area is too low!
Thanks for the information and congratulation for a nice spin-off company NanoCollTech.
As far of R&D work in the area of applications of self-cleaning properties of titania, there are many of them. My research group at ENSCL in collaboration of FhG in Dresden have done some studies on the area. My concern and my question was related rather to the diffusion of this application in indutrial practice. Especially, as far as the coatings, which are my speciality, are concerned
To Matteo Leoni's answer: how would you explain the influence of size of titania particles on the photo-catalytoc properties? Does size modifies e.g. the width of forbidden zone?
For sure size has an effect on the band gap, but of course the smaller the size, the higher the specific area
To Lech Pawlowski:
TiO2 size (and morphological propoerties) have implications implications in photocatalysis. We tried to summarize them
"Advanced nanoarchitectures for solar photocatalytic applications."
Anna Kubacka, Marcos Fernández-García, Gerardo Colón
This review (section 1.2 for titania) is available at Researchgate.
Hope that this helps.
To Marcos Fernandez-Garcia
I have just downloaded and thank you. I am about to start a PhD thesis on the photo-catalytic effect in suspension plasma sprayed titania after having done some studies in the past (see:
https://www.researchgate.net/publication/229236995_Suspension_plasma_sprayed_TiO2_coatings_using_different_injectors_and_their_photocatalytic_properties).
The advantage of suspension plasma spraying is its two-zones microstructure in which one zone preserve fine crystallinity (see:
https://www.researchgate.net/publication/223571654_Two_zones_microstructure_of_suspension_plasma_sprayed_hydroxyapatite_coatings
and, on the other hand, the solidification conditions of TiO2 are such that anatase phase is formed (see :
https://www.researchgate.net/publication/222199663_Suspension_and_solution_thermal_spray_coatings
I would be interested on a collaboration and maybe some european projects.
Article Suspension plasma sprayed TiO2 coatings using different inje...
Article Two Zones Microstructure of Suspension Plasma Sprayed Hydrox...
Article Suspension and Solution Thermal Spray Coatings
To Lech Pawlowski
Many thanks for the information. Will read with care.
Of course, it would be nice to collaborate in any way you may think of interest.
To Iis Sopyan
Thank you for the information. I guess water comes from air humidity and uv radiation can irradiate a pillow by bringing it from to time under the sun.
Thank you for the information. I will keep it in my mind and maybe one day it will become possible to use it.
Dear Dr. Pawlowski:
We have developed practical photocatalytic air-purifiers. Please confirm our manuscripts below. These are downloadable from my RG page. You can obtain certain interesting information.
1. DOI: 10.1016/j.jphotochemrev.2012.07.001
2. DOI: 10.5796/electrochemistry.82.720
3. DOI: 10.3390/molecules191117424
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