Investigation of the enhanced photocathodic activity of La5Ti2CuS5O7photocathodes in H2evolution by synchrotron radiation nanospectroscopy.
The local electronic structures of La5Ti2MS5O7(M = Cu, Ag) particulate photoelectrodes with and without Ga doping were investigated, using a photoemission spectroscopy system with a lateral resolution of approximately 100 nm. The band alignments for La5Ti2MS5O7were determined on the basis of pinpoint photoemission spectra acquired at optimal positions on the sample surfaces. A clear upward chemical potential shift of approximately 0.35 eV was observed in the case of Ga-doped La5Ti2CuS5O7. On the other hand, the electronic structure of La5Ti2AgS5O7remained almost unaffected by Ga doping. These results explain the enhanced photocathodic response of La5Ti2CuS5O7upon Ga doping.
Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Enju
E
Sakai
Naoka
N
Nagamura
Jingyuan
J
Liu
Takashi
T
Hisatomi
Taro
T
Yamada
Kazunari
K
Domen
Masaharu
M
Oshima