A synthesis of noble metal nanosheets and their alloying process

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05228
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: Kyoto University
• Principal Investigator: Fukuda Katsutoshi 京都大学, 産官学連携本部, 教授 (80504331)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ナノシート / 貴金属 / 合金化

Outline of Final Research Achievements

Aim of this study is to create new metal nanosheets and conductive nanosheets. We have succeeded in a synthesis of new 2D nano-materials being composed of platinum atomic layers through a topotactic conversion of platinum oxides nanosheets exfoliated from layered platinum oxides. The resultant nanosheets have a 2D rectangular cell in the lateral dimension unlike the case with the monolayer nanosheets of hexagonal close-packed ruthenium reported in our previous literature. Interestingly, both metal monolayer nanosheets on glass wafers are insulator when the number of the monolayer stacking is less than 2. In the case of more than 3 platinum layers, metallic state can be observed as well as the ruthenium case.
Besides, we have tied to fabricate metal nanosheets consisting of transition metal atoms. Although this attempt was not successful, conductive MoO3-x nanosheets having a large amount of vacancies were obtained by a pseudo-topotactic conversion of exfoliated MoO2 nanosheets.

Free Research Field

無機化学

Academic Significance and Societal Importance of the Research Achievements

三次元的に構造を取りやすい金属では、長らく３次元的にサイズをスケールダウンしたナノ粒子などがナノマテリアル研究の中心であった。我々が本研究等で創製してきた二次元ナノ金属群は大きな構造異方性を有することから、三次元バルクの状態と比べてそれらの構成元素は必然的に特異な結合状態を形成している。バルクでは優秀な電極として知られている白金でも白金ナノシート単層状態では絶縁体であった。このように構成元素間の結合状態と金属状態の発現は密接に結びついており、原子層数を厳密に制御した二次元ナノ金属薄膜をデザインすることで金属の新たな理解に繋がる。