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

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• 作者：Martin Ferus ; Ladislav Kavan ; Mark茅ta Zukalov谩 ; Arno拧t Zukal ; Mariana Klementov谩 ; Svatopluk Civi拧
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：November 20, 2014
• 年：2014
• 卷：118
• 期：46
• 页码：26845-26850
• 全文大小：346K
• ISSN：1932-7455

文摘

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 掳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 掳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 掳C.