Fuel from Water: Nano-structured oxide semiconductor composites for photocatalysis

ORAL

Abstract

Photo-catalytic hydrogen production has been observed using TiO2 as a catalyst to decompose water but has proved impractical in application. The inefficiency of TiO2 is a result of its large bandgap which only permits absorption in the UV range of light and not visible light. Complex oxide-semiconductors are potentially a more effective candidate for photocatalysis of water in that they provide both the electrons from a smaller band gap semiconductor and the catalyst from the oxide surface. We examine an oxide-semiconductor composite of BaTiO3 grown on Ge using the Molecular Beam Epitaxy (MBE) technique by measuring electrical transport to understand the physics of photo-generated carriers. Understanding these electrical transport characteristics will assist in optimizing the efficiency of the nanostructured composite for its eventual use in a reduction reaction of water. The photo-generated surface electrons are observed when the composite is placed in AgNO3 solution and irradiated with visible light. Ag+ reduces because of the available surface electrons forming Ag [solid] grains which are deposited on the surface and observed using a scanning electron microscope with energy dispersive X-ray spectroscopy.

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Authors

  • Doug Ball

    Utah State University

  • Young-Yeal Song

    Brigham Young University, Colorado School of Mines, Colorado State University, Yale University, Department of Physics and Astronomy, Brigham Young University, Department of Mechanical Engineering, University of Utah, JILA, NIST and University of Colorado, University of Arizona, MIT, National Institute for Materials Science, Japan, Department of Mechanical Engineering, Brigham Young University, University of New Mexico, Iowa State University, Los Alamos National Lab XCP-2, Utah State University, Weber State University, New Mexico State University, College of Optical Science, University of Arizona, University of Nebraska, Lincoln, J.A. Woollam Co., U.S. Naval Research Laboratory, Arizona State University, BYU Nuclear Physics Group, Brigham Young University Physics and Astronomy, Los Alamos National Laboratory, University of Tsukuba, Japan, Colorado State University, NSF ERC for EUV science and technology, Center for Functional Nanomaterials, Brookhaven National Laboratory, University of Wisconsin, Madison, Utah Valley University, Argonne National Lab

  • Young-Yeal Song

    Brigham Young University, Colorado School of Mines, Colorado State University, Yale University, Department of Physics and Astronomy, Brigham Young University, Department of Mechanical Engineering, University of Utah, JILA, NIST and University of Colorado, University of Arizona, MIT, National Institute for Materials Science, Japan, Department of Mechanical Engineering, Brigham Young University, University of New Mexico, Iowa State University, Los Alamos National Lab XCP-2, Utah State University, Weber State University, New Mexico State University, College of Optical Science, University of Arizona, University of Nebraska, Lincoln, J.A. Woollam Co., U.S. Naval Research Laboratory, Arizona State University, BYU Nuclear Physics Group, Brigham Young University Physics and Astronomy, Los Alamos National Laboratory, University of Tsukuba, Japan, Colorado State University, NSF ERC for EUV science and technology, Center for Functional Nanomaterials, Brookhaven National Laboratory, University of Wisconsin, Madison, Utah Valley University, Argonne National Lab