溶融水酸化物における酸化状態制御によるニッケル硫化物の新化合物および相選択

Xiuquan Zhou¹, David J Mandia¹, Hyowon Park²

¹Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States.

Journal of the American Chemical Society

|August 19, 2021

まとめ

溶けた水酸化物の混合は,新しいニッケル硫化物の発見のための強力な溶媒として作用する. この方法は,ニッケルを正確に制御します.

科学分野:

材料科学
固体化学
無機化学

背景:

溶けた塩は新しい物質の発見に有望ですが,酸化状態の制御は限られています.
水溶液は酸化状態の制御を良くするが,特定の材料の合成には効果が低い.

研究の目的:

混合溶融ヒドロキシドが素材合成の調節可能な流体として機能することを実証する.
三重カルコゲニド単体結晶の成長のためのニッケル酸化状態の正確な制御を達成するために.
新しい三元と二元ニッケル硫化物相とその性質を探求する.

主な方法:

溶けたLiOH/KOHの混合フロースを用いた三元K-Ni-S化合物の合成.
新しいニッケル硫化物の結晶成長と相識別
X線吸収光譜 (XAS),X線光電子光譜 (XPS),密度関数理論 (DFT) の計算を用いた特徴付け.

主要な成果:

LiOH/KOH溶液でNi酸化状態の正確な制御が達成され,すべての既知の三元K-Ni-S化合物の成長が可能となった.
いくつかの新しいフェーズが発見され,β-K₂Ni₃S₄,低価KNi₄S₂,およびK₄Ni₉S₁₁の新しいポリトープが発見された.
新しい層のバイナリであるNi₂Sは,KNi₄S₂からKのトポタクシー脱インターケレーションによって合成され,インターケレーション化学に適したヴァン・デル・ワールスのギャップを示した.

結論:

溶融ヒドロキシドの混合は,三元カルコゲニドの制御された合成と結晶の成長のための効果的な流体である.
この研究では,ユニークな構造と電子特性を持つ新しい低価ニッケル硫化物 (KNi₄S₂とNi₂S) に成功しました.
新しく発見されたNi₂Sは,インターケレーション化学のための有望な宿主物質として機能します.

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