title: Enhancement of Charge Separation and Hydrogen Evolution on Particulate La5Ti2CuS5O7Photocathodes by Surface Modification.
abstract: Particulate La5Ti2CuS5O7(LTC) photocathodes prepared by particle transfer show a positive onset potential of 0.9 V vs RHE for the photocathodic current in photoelectrochemical (PEC) H2evolution. However, the low photocathodic current imposes a ceiling on the solar-to-hydrogen energy conversion efficiency of PEC cells based on LTC photocathodes. To improve the photocurrent, in this work, the surface of Mg-doped LTC photocathodes was modified with TiO2, Nb2O5, and Ta2O5by radio frequency reactive magnetron sputtering. The photocurrent of the modified Mg-doped LTC photocathodes was doubled because these oxides formed type-II heterojunctions and extended the lifetimes of photogenerated charge carriers. The enhanced photocathodic current was attributed to hydrogen evolution at a positive potential of +0.7 V vs RHE. This work opens up possibilities for improving PEC hydrogen evolution on particulate photocathodes based on surface oxide modifications and also highlights the importance of the band gap alignment.
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
authors.forename: Takashi
authors.identifier: http://orcid.org/0000-0002-5009-2383
authors.initials: T
authors.lastname: Hisatomi
authors.affiliation: National Institute of Advanced Industrial Science and Technology , Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Ibaraki, Japan.
authors.forename: Dharmapura H K
authors.initials: DH
authors.lastname: Murthy
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
authors.forename: Miao
authors.initials: M
authors.lastname: Zhong
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , 2-11-16 Yayoi, Bunkyo-ku, 113-8656 Tokyo, Japan.
authors.forename: Mamiko
authors.initials: M
authors.lastname: Nakabayashi
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Higashi
authors.affiliation: National Institute of Advanced Industrial Science and Technology , Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Ibaraki, Japan.
authors.forename: Yohichi
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: National Institute of Advanced Industrial Science and Technology , Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Ibaraki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsuzaki
authors.affiliation: National Institute of Advanced Industrial Science and Technology , Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Ibaraki, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Seki
authors.affiliation: National Institute of Advanced Industrial Science and Technology , Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Ibaraki, Japan.|Department of Optical Science, Tokushima University , 2-1 Minamijosanjima-cho, 770-8506 Tokushima, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Furube
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , 2-11-16 Yayoi, Bunkyo-ku, 113-8656 Tokyo, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Katayama
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.|Japan Science and Technology Agency/Precursory Research for Embryonic Science and Technology (JST/PRESTO) , Kawaguchi Center Building, 4-1-8 Honcho, Kawaguchi-shi, 332-0012 Saitama, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Minegishi
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.|Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
authors.forename: Kazunari
authors.identifier: http://orcid.org/0000-0001-7995-4832
authors.initials: K
authors.lastname: Domen