Experimental and Theoretical Characterization of the Optical Properties of CeO2, SrCeO3, and Sr2CeO4 Containing Ce4+ (f0) Ions.

Goubin, Fabrice; Rocquefelte, Xavier; Whangbo, Myung‐Hwan; Montardi, Yvan; Brec, R.; Jobic, Stéphane

doi:10.1002/chin.200417017

Cited by 16 publications

(37 citation statements)

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“…Specifically, E g increases practically linearly under compressive biaxial strain, reaching a maximum value of 3.4 eV at η = −7%. According to our DFT calculations the band gap of unstrained CeO 2 is 3.1 eV, which compares very well with the experimental value of 3.2 eV [38], hence a maximum relative E g increase of 10% is achieved. Under tensile biaxial strain, E g also varies significantly although not in a regular manner.…”

Section: A Fluorite Ceo2 (111)supporting

confidence: 87%

Strain engineering of oxide thin films for photocatalytic applications

et al. 2020

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Photocatalytic materials are pivotal for the implementation of disruptive clean energy applications such as conversion of H2O and CO2 into fuels and chemicals driven by solar energy. However, efficient and cost-effective materials able to catalyze the chemical reactions of interest when exposed to visible light are scarce due to the stringent electronic conditions that they must satisfy. Chemical and nanostructuring approaches are capable of improving the catalytic performance of known photoactive compounds however the complexity of the synthesized nanomaterials and sophistication of the employed methods make systematic design of photocatalysts difficult. Here, we show by means of first-principles simulation methods that application of biaxial stress, η, on semiconductor oxide thin films can modify their optoelectronic and catalytic properties in a significant and predictable manner. In particular, we show that upon moderate tensile strains CeO2 and TiO2 thin films become suitable materials for photocatalytic conversion of H2O into H2 and CO2 into CH4 under sunlight. The band gap shifts induced by η are reproduced qualitatively by a simple analytical model that depends only on structural and dielectric susceptibility changes. Thus, epitaxial strain represents a promising route for methodical screening and rational design of photocatalytic materials.

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Section: A Fluorite Ceo2 (111)supporting

confidence: 87%

Strain engineering of oxide thin films for photocatalytic applications

et al. 2020

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“…The energy bandgap of E G 3.2 eV and the refractive index n 2.35 have been obtained in Ref. [27] and in Ref. [45], respectively.…”

Section: Ceomentioning

confidence: 89%

“…Thus, strictly speaking, the validity of the determined optical properties here would be for energies above the visible, but this procedure was applied in references used for the comparison of our results (Ref. [27], for instance).…”

Section: Data Analysis Proceduresmentioning

confidence: 99%

“…The number of papers dealing with electronic or optical properties of CeO 2 (from an experimental or theoretical point of view) is quite large (see Refs. [17,27,[45][46][47][48][49], for instance), but no parametrization of the ELF into oscillators was proposed, and moreover, no unanimity exists about interpretation of the various transitions. We summarize below the different propositions made to explain the spectra.…”

Section: Ceomentioning

confidence: 99%

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Optical properties and electronic transitions of zinc oxide, ferric oxide, cerium oxide, and samarium oxide in the ultraviolet and extreme ultraviolet

et al. 2017

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Optical properties and electronic transitions of four oxides, namely zinc oxide, ferric oxide, cerium oxide, and samarium oxide, are determined in the ultraviolet and extreme ultraviolet by reflection electron energy loss spectroscopy using primary electron energies in the range 0.3-2.0 keV. This technique allows the evaluation of the optical response in these ultraviolet spectral regions of a thin layer of material, and the analysis is straightforward. It is performed within the dielectric response theory by means of the QUEELS-ε(k, ω)-REELS software developed by Tougaard and Yubero [Surf. Interface Anal.36, 824 (2004)SIANDQ0142-242110.1002/(ISSN)1096-9918]. The method consists basically in the fitting of experimentally determined single-scattering electron energy loss cross sections with a parametric energy loss function of the corresponding material, to the one calculated within a dielectric response formalism. The obtained refractive index and extinction coefficients, as well as the identified electronic transitions are compared, when available, with previously published results.

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“…Ce 4+ , on the other hand, shows strong charge transfer excitation in the near‐ultraviolet (UV)/violet region, but seldom any luminescence, Sr 2 CeO 4 being noted as an exception (10,11). In fact Ce 4+ compounds can be used as efficient filters for the UVA and UVB regions (12). We have studied the decomposition products of Ce(SO 4 ) 2 .4H 2 O using the photoluminescence techniques, with the view to answering the question of whether cerous salts are formed at any stage during such decomposition.…”

Section: Introductionmentioning

confidence: 99%