赤铁矿
化学
催化作用
反应机理
反应速率
化学工程
光化学
化学物理
矿物学
有机化学
工程类
作者
Florian Le Formal,Ernest Pastor,S. David Tilley,Camilo A. Mesa,Stephanie R. Pendlebury,Michaël Grätzel,James R. Durrant
摘要
Water oxidation is a key chemical reaction, central to both biological photosynthesis and artificial solar fuel synthesis strategies. Despite recent progress on the structure of the natural catalytic site, and on inorganic catalyst function, determining the mechanistic details of this multiredox reaction remains a significant challenge. We report herein a rate law analysis of the order of water oxidation as a function of surface hole density on a hematite photoanode employing photoinduced absorption spectroscopy. Our study reveals a transition from a slow, first order reaction at low accumulated hole density to a faster, third order mechanism once the surface hole density is sufficient to enable the oxidation of nearest neighbor metal atoms. This study thus provides direct evidence for the multihole catalysis of water oxidation by hematite, and demonstrates the hole accumulation level required to achieve this, leading to key insights both for reaction mechanism and strategies to enhance function.
科研通智能强力驱动
Strongly Powered by AbleSci AI