Pivotal Role and Regulation of Proton Transfer in Water Oxidation on Hematite Photoanodes

	Pivotal Role and Regulation of Proton Transfer in Water Oxidation on Hematite Photoanodes
	Zhang, Yuchao; Zhang, Hongna; Ji, Hongwei; Ma, Wanhong; Chen, Chuncheng; Zhao, Jincai
刊名	JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
	2016-03-02
卷号	138 期号:8 页码:2705-2711
英文摘要	Hematite is a promising material for solar water splitting; however, high efficiency remains elusive because of the kinetic limitations of interfacial charge transfer. Here, we demonstrate the pivotal role of proton transfer in water oxidation on hematite photoanodes using photoelectrochemical (PEC) characterization, the H/D kinetic isotope effect (KIE), and electrochemical impedance spectroscopy (EIS). We observed a concerted proton-electron transfer (CPET) characteristic for the rate-determining interfacial hole transfer, where electron transfer (ET) from molecular water to a surface-trapped hole was accompanied by proton transfer (PT) to a solvent water molecule, demonstrating a substantial KIE (similar to 3.5). The temperature dependency of KIE revealed a highly flexible proton transfer channel along the hydrogen bond at the hematite/electrolyte interface. A mechanistic transition in the rate-determining step from CPET to ET occurred after OH- became the dominant hole acceptor. We further modified the proton electron transfer sequence with appropriate proton acceptors (buffer bases) and achieved a greater than 4-fold increase in the PEC water oxidation efficiency on a hematite photoanode.
收录类别	SCI
语种	英语
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/35880]
专题	化学研究所_光化学实验室
作者单位	Chinese Acad Sci, Inst Chem, Beijing Natl Lab Mol Sci, Key Lab Photochem, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Yuchao,Zhang, Hongna,Ji, Hongwei,et al. Pivotal Role and Regulation of Proton Transfer in Water Oxidation on Hematite Photoanodes[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2016,138(8):2705-2711.
APA	Zhang, Yuchao,Zhang, Hongna,Ji, Hongwei,Ma, Wanhong,Chen, Chuncheng,&Zhao, Jincai.(2016).Pivotal Role and Regulation of Proton Transfer in Water Oxidation on Hematite Photoanodes.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,138(8),2705-2711.
MLA	Zhang, Yuchao,et al."Pivotal Role and Regulation of Proton Transfer in Water Oxidation on Hematite Photoanodes".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 138.8(2016):2705-2711.