Surface characteristics and electronic structure of photocatalytic reactions on TiO2 and doped TiO2 nanoparticles
2006 (English)In: Solar Hydrogen and Nanotechnology, 2006, U5-U19 p.Conference paper (Refereed)
A molecular approach to understand the photocatalytic degradation of small organic molecules adsorbed from the gas phase on anatase, rutile and doped TiO2 nanoparticles is presented. Using in situ Fourier transform infrared (FTIR) spectroscopy and mass spectrometry the rate determining steps for the photocatalytic degradation of formic acid, acetone and propane are unraveled. Key intermediates are identified and correlated to structural properties of the TiO2 nanoparticles. Specifically, stable bridging bidentate carboxylate (R-CO2) and (bi)carbonate species forms preferentially on rutile particles, and are proposed to inhibit the total photodegradation efficiency. In particular, the concentration of R-CO2 is found to decrease with increasing size of the anatase particles, and may at least partly explain why Degussa P25 is a good photocatalyst. Means to avoid R-CO2 site-blocking is discussed. Improved solar light efficiencies are difficulty to achieve in cation doped TiO2 despite higher visible light absorption and stronger adsorbate-surface interactions.
Place, publisher, year, edition, pages
2006. U5-U19 p.
, PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE), ISSN 0277-786X ; 6340
photocatalysis, TiO2, Nb, Zr, nanoparticles, Fourier transform infrared spectroscopy, formate, acetone, propane
Physical Chemistry Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-235875DOI: 10.1117/12.680304ISI: 000243024600001ISBN: 0-8194-6419-8OAI: oai:DiVA.org:uu-235875DiVA: diva2:762442
Conference on Solar Hydrogen and Nanotechnology, AUG 14-17, 2006, San Diego, CA