title: Self-Assembled Heteroepitaxial Oxide Nanocomposite for Photoelectrochemical Solar Water Oxidation.
abstract: We report on spontaneously phase ordered heteroepitaxial SrTiO3(STO):ZnFe2O4(ZFO) nanocomposite films that give rise to strongly enhanced photoelectrochemical solar water oxidation, consistent with enhanced photoinduced charge separation. The STO:ZFO nanocomposite yielded an enhanced photocurrent density of 0.188 mA/cm2at 1.23 V vs a reversible hydrogen electrode, which was 7.9- and 2.6-fold higher than that of the plain STO film and ZFO film cases under 1-sun illumination, respectively. The photoelectrode also produced stable photocurrent and Faradaic efficiencies of H2and O2formation that were more than 90%. Incident-photon-to-current-conversion efficiency measurements, Tauc plots, Mott-Schottky plots, and electrochemical impedance spectroscopy measurements proved that the strongly enhanced photogenerated charge separation resulted from vertically aligned pseudosingle crystalline components, epitaxial heterojunctions, and a staggered band alignment of the components of the nanocomposite films. This study presents a completely new avenue for efficient solar energy conversion applications.
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
authors.forename: Seungho
authors.initials: S
authors.lastname: Cho
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie Gmbh, Institute for Solar Fuels, Hahn-Meitner-Platz 1, Berlin 14109, Germany.
authors.forename: Ji-Wook
authors.initials: JW
authors.lastname: Jang
authors.affiliation: Department of Materials Science and Engineering and Department of Electrical and Computer Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Leigang
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering and Department of Electrical and Computer Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Jian
authors.affiliation: Department of Materials Science and Engineering and Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States; Department of Materials Science and Engineering and Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
authors.forename: Judith L
authors.initials: JL
authors.lastname: MacManus-Driscoll