An electronic structure governed by the displacement of the indium site in In-S6 octahedra: LnOInS2 (Ln = La, Ce, and Pr)

Hiroaki Ito; Akira Miura; Yosuke Goto; Yoshikazu Mizuguchi; Chikako Moriyoshi; Yoshihiro Kuroiwa; Masaki Azuma; Jinjia Liu; Xiao-Dong Wen; Shunta Nishioka; Kazuhiko Maeda; Yuji Masubuchi; Nataly Carolina Rosero-Navarro; Kiyoharu Tadanaga

doi:10.1039/c9dt01562k

An electronic structure governed by the displacement of the indium site in In-S₆ octahedra: LnOInS₂ (Ln = La, Ce, and Pr)

Dalton Trans. 2019 Aug 28;48(32):12272-12278. doi: 10.1039/c9dt01562k. Epub 2019 Jul 24.

Affiliations

¹ Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Sapporo 060-8628, Japan.
² Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Sapporo 060-8628, Japan. amiura@eng.hokudai.ac.jp.
³ Department of Physics, Tokyo Metropolitan University, 1-1 Minami-osawa, Hachioji, Tokyo 192-0397, Japan.
⁴ Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8526, Japan.
⁵ Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
⁶ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P. R. China.
⁷ Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-2 Ookayama, Meguro-ku, Tokyo 152-8550, Japan and Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan.
⁸ Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-2 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.

PMID: 31339138
DOI: 10.1039/c9dt01562k

Abstract

An extremely large displacement of the indium site in In-S₆ octahedra in LnOInS₂ (Ln = La, Ce, and Pr) was found in synchrotron X-ray diffraction. LaOInS₂ with off-center indium in In-S₆ octahedra exhibited a wider optical band gap than CeOInS₂ and PrOInS₂ with on-center indium. Therefore, the electronic structure of LnOInS₂ is governed by the indium site with an extremely large displacement. All LnOInS₂ produced H₂ gas under visible light irradiation in the presence of sacrificial electron donors.