Selective plasmonic gas sensing: H 2, NO 2, and CO spectral discrimination by a single Au-CeO 2 nanocomposite film

Nicholas A. Joy, Manjula I. Nandasiri, Phillip H. Rogers, Weilin Jiang, Tamas Varga, Satyanarayana V.N.T. Kuchibhatla, Suntharampillai Thevuthasan, Michael A. Carpenter

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    Abstract

    A Au-CeO 2 nanocomposite film has been investigated as a potential sensing element for high-temperature plasmonic sensing of H 2, CO, and NO 2 in an oxygen containing environment. The CeO 2 thin film was deposited by molecular beam epitaxy (MBE), and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. The Au-CeO 2 nanocomposite film was characterized by X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H 2, CO, and NO 2 were performed at a temperature of 500 °C in oxygen backgrounds of 5.0, 10, and ∼21% O 2. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the CeO 2. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles (AuNPs) or by changes in the dielectric constant surrounding the particles. Spectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used and showed separation between analytes as well as trends in gas concentration. Results indicate that the Au-CeO 2 thin film is selective to O 2, H 2, CO, and NO 2 in separate exposures. This, combined with the observed stability over long exposure periods, shows the Au-CeO 2 film has good potential as an optical sensing element for harsh environmental conditions.

    Original languageEnglish
    Pages (from-to)5025-5034
    Number of pages10
    JournalAnalytical Chemistry
    Volume84
    Issue number11
    DOIs
    Publication statusPublished - 5 Jun 2012

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    ASJC Scopus subject areas

    • Analytical Chemistry

    Cite this

    Joy, N. A., Nandasiri, M. I., Rogers, P. H., Jiang, W., Varga, T., Kuchibhatla, S. V. N. T., Thevuthasan, S., & Carpenter, M. A. (2012). Selective plasmonic gas sensing: H 2, NO 2, and CO spectral discrimination by a single Au-CeO 2 nanocomposite film. Analytical Chemistry, 84(11), 5025-5034. https://doi.org/10.1021/ac3006846