Photosensitization of TiO2 Nanostructures with CdS Quantum Dots: Particulate versus Tubular Support Architectures

Authors

  • David R. Baker,

    1. Department of Chemical and Biomolecular Engineering Radiation Laboratory University of Notre Dame Notre Dame, IN 46556 (USA)
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  • Prashant V. Kamat

    Corresponding author
    1. Department of Chemistry and Biochemistry Department of Chemical and Biomolecular Engineering Radiation Laboratory University of Notre Dame Notre Dame, IN 46556 (USA)
    • Department of Chemistry and Biochemistry Department of Chemical and Biomolecular Engineering Radiation Laboratory University of Notre Dame Notre Dame, IN 46556 (USA).
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Abstract

TiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons.

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