Ionic control of mixed-anion compounds and reduced oxides using electric field

• Project/Area Number: 19F19334
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 外国
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: Kyoto University
• Principal Investigator: 陰山 洋 京都大学, 工学研究科, 教授 (40302640)
• Co-Investigator(Kenkyū-buntansha): LI HAOBO 京都大学, 工学(系)研究科(研究院), 外国人特別研究員
• Project Period (FY): 2019-10-11 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥2,300,000 (Direct Cost: ¥2,300,000); Fiscal Year 2021: ¥400,000 (Direct Cost: ¥400,000); Fiscal Year 2020: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 2019: ¥700,000 (Direct Cost: ¥700,000)
• Keywords: Ionic manipulation / Electric-field control / Phase transition / Topochemical reaction / Proton insertion / Complex oxide / Mixed-anions / Thin film

Outline of Research at the Start

The electric-field controlled protonation of reduced perovskite and mixed-anion oxid
e are still untouched. Therefore, the main purpose of the proposed research is to reveal the electric-field controlled protonation of these novel systems. Several interesting and fundamental questions will be answered through this project. (1) Can we manipulate ions in vacancy rich layered reduced perovskite oxides using electric-field controlled ionic manipulation? (2) Can we realize electric-field controlled proton injection in oxyhydrides? (3) How will H+ behave in mixed-anion oxide materials?

Outline of Annual Research Achievements

Our work shows that using the electrochemical protonation and associated dehydration reaction paves out a novel route to explore reduced metal oxides. The dehydration is also simple but effective. It is quite similar as the general dehydration occurs in ATP or alcohol synthesis, where the bonding oxygen is removed and new bonding and structure are formed. However, the electric-field provides additional energy to weaken the metal-oxygen hybridization. Thus, the lattice oxygen can be easily released from the system under heating, when these oxygen ions cannot be removed by other methods.
The obtained SrCoO2 exhibits unique 4-legged spin-tube structure, which cannot be obtained by well-known reduction reactions. Considering the electrochemical protonation is well explored in many oxides, large number of precursors can be considered to explore their products after dehydration. Even for known oxyhydride, electrochemical protonation might further reduce these compounds and H2 releasing instead of H2O can be expected. More importantly, the proton injection/dehydration could be expanded to all types of materials and this will eventually reveal large number of undiscovered structures and associated exotic properties.
In the final fiscal year of this funding, our results were accepted by Journal of the American Chemical Society (J. Am. Chem. Soc. 2021, 143, 42, 17517-17525). The related results will be also presented in JSAP 69th conference in 2022 Spring.

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Dehydration of Electrochemically Protonated Oxide: SrCoO2 with Square Spin Tubes (2021)
  • Author(s): Li Hao-Bo、Kobayashi Shunsuke、Zhong Chengchao、Namba Morito、Cao Yu、Kato Daichi、Kotani Yoshinori、Lin Qianmei、Wu Maokun、Wang Wei-Hua、Kobayashi Masaki、Fujita Koji、Tassel Cedric、Terashima Takahito、Kuwabara Akihide、Kobayashi Yoji、Takatsu Hiroshi、Kageyama Hiroshi
  • Journal Title: Journal of the American Chemical Society Volume: 143 Issue: 42 Pages: 17517-17525
  • DOI: 10.1021/jacs.1c07043
  • Peer Reviewed / Int'l Joint Research