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Publication
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| Title of Article |
Effects of Ce addition on the properties and photocatalytic activity of TiO2, investigated by X-ray absorption spectroscopy |
| Date of Acceptance |
5 April 2018 |
| Journal |
| Title of Journal |
Materials Chemistry and Physics |
| Standard |
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| Institute of Journal |
2018 Elsevier B.V. All rights reserved |
| ISBN/ISSN |
0254-0584 |
| Volume |
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| Issue |
213 |
| Month |
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| Year of Publication |
2018 |
| Page |
431-443 |
| Abstract |
TiO2, 0.1, 1, 3 and 8 wt% Ce-doped TiO2 photocatalysts were prepared by sol-gel method. All prepared
samples were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, Scanning electron
microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Raman spectroscopy and Xray absorption spectroscopy (XAS). Upon Ce addition into TiO2, the phase structure of doped samples
were similar to that of pure TiO2. The expansion of unit cell parameters and the shifting of Raman
peaks to higher wavenumbers indicated to the incorporation of Ce ions into TiO2 structure resulting in
the formation of lattice defects. The optical properties indicated that the addition of Ce into TiO2
enhanced the visible light absorption of the photocatalyst due to a reduction of band gap energy. For
XANES study, it was found that the oxidation state of Ce in Ce-doped TiO2 showed the mixture of Ce3þ
and Ce4þ which confirmed the formation of oxygen vacancies or lattice defect. The EXAFS results
indicated that larger Ce ions were incorporated in TiO2 lattices and the structure of Ce-doped TiO2
deviated from the octahedral symmetry on the Ti site surrounded by six O atoms. The photocatalytic
activity of all samples were investigated for degradation of methyl orange (MO) dye under UV light
irradiation with a catalyst dosage of 0.3 g L1, pH 2 and light intensity of 125 W. The Methyl orange
removal percentage of TiO2 was 80.4% for TiO2 which was increased up to 86.9% for 0.1 wt% Ce-doped
TiO2. The enhancing of photocatalytic activity was possibly due to the formation of energy levels by
Ce3þ/Ce4þ and oxygen vacancy under the conduction band of TiO2 which can trap electrons and
resulting in a reduction of charge recombination. However, further upon increase of Ce content, the removal percentage decreased due to the formation of recombination centers from an overabundance
of oxygen vacancies in the TiO2 lattice. |
| Keyword |
Ce-doped TiO2 XANES EXAFS Methyl orange photodegradation oxygen vacancies |
| Author |
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| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
true |
| Part of thesis |
true |
| Attach file |
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| Citation |
0
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Journal Publication
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