Spontaneous and Photoinduced Conversion of CO2 on TiO2 Anatase (001)/(101) Surfaces

0437179 - ÚFCH JH 2015 RIV US eng J - Journal Article
Ferus, Martin - Kavan, Ladislav - Zukalová, Markéta - Zukal, Arnošt - Klementová, Mariana - Civiš, Svatopluk
Spontaneous and Photoinduced Conversion of CO2 on TiO2 Anatase (001)/(101) Surfaces.
Journal of Physical Chemistry C. Roč. 118, č. 46 (2014), s. 26845-26850. ISSN 1932-7447. E-ISSN 1932-7455
R&D Projects: GA ČR(CZ) GAP108/12/0814; GA MŠMT LD14115; GA MŠMT(CZ) LD13060
Grant - others:COST(XE) CM1104
Institutional support: RVO:61388955 ; RVO:61388980 ; RVO:68081707
Keywords : TiO2 * FT-IR spectroscopy * nanocrystalline anatase
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 4.772, year: 2014

High-resolution FT-IR spectroscopy was used to study the kinetics of oxygen mobility between gaseous isotopically labeled C18O2 and solid phase Ti16O2 nanocrystalline anatase (001). Analysis of the isotopic composition of the gases produced has revealed that anatase (001) calcinated at temperatures under 500 °C is a very weakly reactive material and exhibits a low exchange mobility of oxygen atoms between the gas phase molecules of CO2 and the TiO2 lattice. Isotope exchange is blocked by both residual HF adsorbed onto the TiO2 surface and TiOF2 impurities. The presence of TiOF2 was shown by TEM and X-ray diffraction. However, the anatase (001) sample became slightly active after annealing at temperatures higher than 500 °C and upon UV illumination. Nevertheless, the effective rate constant is still 3.45 times lower than that observed for the spontaneous exchange between C18O2 and anatase (101) material calcinated at 500 °C.
Permanent Link: http://hdl.handle.net/11104/0240741