TY - JOUR
T1 - Photoelectrochemical properties of crystalline perovskite lanthanum titanium oxynitride films under visible light
AU - Paven-Thivet, Claire Le
AU - Ishikawa, Akio
AU - Ziani, Ahmed
AU - Gendre, Laurent Le
AU - Yoshida, Masaaki
AU - Kubota, Jun
AU - Tessier, Franck
AU - Domen, Kazunari
PY - 2009/4/16
Y1 - 2009/4/16
N2 - Thin films of the lanthanum titanium oxynitride perovskite (LaTiO xNy) synthesized by reactive radio-frequency sputtering on conductive Nb-doped strontium titanate (Nb:SrTiO3) substrates are evaluated as photoelectrodes for water splitting reaction under visible light. The films are characterized by X-ray diffraction analysis, energy-dispersive spectroscopy, scanning electron and atomic force microscopy, and ultraviolet - visible spectroscopy. Thin films with polycrystalline, oriented, or epitaxial structures are obtained depending on the substrate temperature and plasma composition. The band-gap energies of the films thus prepared are in the range 2.05-2.35 eV. Photoelectrochemical measurements reveal that the photoactivity of these films increases with the quality of film crystallization. The flat-band position of LaTiOxNy is found to change with pH of the reactant solution. Surface modification with colloidal IrO2is also demonstrated to result in a marked increase in photoactivity, with the modified epitaxial LaTiOxNy film exhibiting a photocurrent density of ca. 70 μA cm-2 at +1.0 V vs. Ag/AgCl at pH 4.5 in aqueous Na2SO4 solution under irradiation at visible wavelengths (λ > 420 nm).
AB - Thin films of the lanthanum titanium oxynitride perovskite (LaTiO xNy) synthesized by reactive radio-frequency sputtering on conductive Nb-doped strontium titanate (Nb:SrTiO3) substrates are evaluated as photoelectrodes for water splitting reaction under visible light. The films are characterized by X-ray diffraction analysis, energy-dispersive spectroscopy, scanning electron and atomic force microscopy, and ultraviolet - visible spectroscopy. Thin films with polycrystalline, oriented, or epitaxial structures are obtained depending on the substrate temperature and plasma composition. The band-gap energies of the films thus prepared are in the range 2.05-2.35 eV. Photoelectrochemical measurements reveal that the photoactivity of these films increases with the quality of film crystallization. The flat-band position of LaTiOxNy is found to change with pH of the reactant solution. Surface modification with colloidal IrO2is also demonstrated to result in a marked increase in photoactivity, with the modified epitaxial LaTiOxNy film exhibiting a photocurrent density of ca. 70 μA cm-2 at +1.0 V vs. Ag/AgCl at pH 4.5 in aqueous Na2SO4 solution under irradiation at visible wavelengths (λ > 420 nm).
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U2 - 10.1021/jp811100r
DO - 10.1021/jp811100r
M3 - Article
AN - SCOPUS:65249092631
VL - 113
SP - 6156
EP - 6162
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 15
ER -