フォトアノード/触媒界面におけるエネルギーと溶解効果:オーム接触対ショットキー障壁

Yuan Ping¹, William A Goddard^1,2, Giulia A Galli^3,4

¹†Joint Center for Artificial Photosynthesis, California Institute of Technology and Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.

Journal of the American Chemical Society

|April 14, 2015

まとめ

フォト電気化学セルのための最適なインターフェースの設計は,水の分裂に不可欠です. この研究は,トングステン三酸化物とイリジウム二酸化物 (IrO2) のナノ粒子の間の粗いインターフェースが,水分裂効率を高めることを明らかにしています.

科学分野:

マテリアルサイエンス材料科学
電気化学電気化学について
量子力学は,量子力学という

背景:

光電化学 (PEC) による水分解は,光電極と触媒の間の効率的なインターフェイスに依存しています.
イリジウム二酸化物 (IrO2) は,酸性媒体での安定性により,有望な酸素進化の触媒である.

研究の目的:

第1原理の計算を用いて,IrO2と接着したトングステン三酸化物 (WO3) 表面の構造的および電子的性質を調査する.
インタフェース形態が水分裂の電荷移転にどのように影響するかを理解する.

主な方法:

第一原理量子力学的計算.
WO3/IrO2インターフェースの顕微鏡モデリング.
形成エネルギー,格子不一致,および電子特性の分析.

主要な成果:

安定した WO3/IrO2 インターフェースは,格子不一致にもかかわらず形成され,有害なフェルミレベルピニングはありません.
WO3をIrO2で完全に覆うことは,不良なオーム接触につながります.
両酸化物の水への部分的な曝露は,電荷移転と水分裂のために好ましい帯域の配列を作り出します.

結論:

完全に覆われたWO3とIrO2の間にはオム式接触が形成され,水の分裂を妨げます.
WO3とIrO2の部分的な水への曝露は,水分裂のための効率的な電荷移転を促進します.
オキシード光電極上のIrO2ナノ粒子によって形成されるような粗いインターフェースは,PECの水分裂を強化するために有利です.

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