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Highly active photocatalyst Bi x Ti y V x O 4 x +2 y ( x ≈ y ) for oxygen evolution under visible‐light illumination
Author(s) -
Liu Haimei,
Imanishi Akihito,
Nakamura Ryuhei,
Nakato Yoshihiro
Publication year - 2008
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200879535
Subject(s) - photocurrent , photocatalysis , chemistry , aqueous solution , visible spectrum , solid state , solid solution , analytical chemistry (journal) , crystallography , materials science , catalysis , biochemistry , optoelectronics , chromatography , organic chemistry
A coupled TiO 2 ‐BiVO 4 system, Bi x Ti y V x O 4 x +2 y ( x ≈ y ), with modified TiO 2 and BiVO 4 crystals through their interaction, was prepared in the form of powder by solid‐state reaction under the concept of combining properties of active photocatalysts. Experiments of photocatalytic oxygen evolution from an aqueous powder suspension under visible‐light irradiation ( λ ≥ 420 nm) have shown that Bi x Ti y V x O 4 x +2 y ( x ≈ y ) exhibits activity much higher than that of BiVO 4 , which is known as one of the most active visible‐light‐responsive photocatalysts, indicating the effectiveness of the interaction and the modification of TiO 2 and BiVO 4 . XRD experiments showed that Bi x Ti y V x O 4 x +2 y ( x ≈ y ) was composed of BiVO 4 and TiO 2 crystals slightly modified probably by partial exchange of V 5+ and Ti 4+ ions. Photocurrent vs. wavelength for a particulate Bi x Ti y V x O 4 x +2 y ( x ≈ y ) film electrode demonstrated several components, in agreement with the conclusion that Bi x Ti y V x O 4 x +2 y ( x ≈ y ) consisted of modified BiVO 4 and TiO 2 crystals. A possible band model was tentatively proposed to explain observed characteristics such as photocurrent density ( j ) vs. potential ( U ), j vs. illumination wavelength ( λ ), the U dependence of j vs. λ , and the effect of the addition of a reductant such as I − , MeOH, SCN − and Br – on j vs. U and j vs. λ . (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)