High-Capacitance Mechanism for Ti3C2TX MXene by in Situ Electrochemical Raman Spectroscopy Investigation

doi:10.1021/acsnano.6b06597

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	High-Capacitance Mechanism for Ti3C2TX MXene by in Situ Electrochemical Raman Spectroscopy Investigation
	Hu, Minmin 1,2; Li, Zhaojin 1,3; Hu, Tao 1,3; Zhu, Shihao 1,3; Zhang, Chao 1; Wang, Xiaohui 1
刊名	ACS NANO
	2016-12-01
卷号	10 期号:12 页码:11344-11350
关键词	MXene two-dimensional materials in situ Raman spectroscopy charging mechanism pseudocapacitance supercapacitor electrochemical capacitor
ISSN号	1936-0851
DOI	10.1021/acsnano.6b06597
通讯作者	Wang, Xiaohui(wang@imr.ac.cn)
英文摘要	MXenes represent an emerging family of conductive two-dimensional materials. Their representative, Ti3C2Tx, has been recognized as an outstanding member in the field of electrochemical energy storage. However, an in-depth understanding of fundamental processes responsible for the superior capacitance of Ti3C2Tx MXene in acidic electrolytes is lacking. Here, to understand the mechanism of capacitance in Ti3C2Tx MXene, we studied electrochemically the charge/discharge processes of Ti3C2Tx electrodes in sulfate ion-containing aqueous electrolytes with three different cations, coupled with in situ Raman spectroscopy. It is demonstrated that hydronium in the H2SO4 electrolyte bonds with the terminal O in the negative electrode upon discharging while debonding occurs upon charging. Correspondingly, the reversible bonding/debonding changes the valence state of Ti element in the MXene, giving rise to the pseudocapacitance in the acidic electrolyte. In stark contrast, only electric double layer capacitance is recognized in the other electrolytes of (NH4)(2)SO4 or MgSO4. The charge storage ways also differ: ion exchange dominates in H2SO4, while counterion adsorption in the rest. Hydronium that is characterized by smaller hydration radius and less charge is the most mobile among the three cations, facilitating it more kinetically accommodated on the deep adsorption sites between the MXene layers. The two key factors, i.e., surface functional group-involved bonding/debonding-induced pseudocapacitance, and ion exchange-featured charge storage, simultaneously contribute to the superior capacitance of Ti3C2Tx MXene in acidic electrolytes.
资助项目	Chinese Academy of Sciences (CAS) ; Shenyang National Laboratory for Materials Science, Institute of Metal Research, CAS
WOS研究方向	Chemistry ; Science & Technology - Other Topics ; Materials Science
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000391079700079
资助机构	Chinese Academy of Sciences (CAS) ; Shenyang National Laboratory for Materials Science, Institute of Metal Research, CAS
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/123544]
专题	金属研究所_中国科学院金属研究所
通讯作者	Wang, Xiaohui
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Hefei 230026, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Hu, Minmin,Li, Zhaojin,Hu, Tao,et al. High-Capacitance Mechanism for Ti3C2TX MXene by in Situ Electrochemical Raman Spectroscopy Investigation[J]. ACS NANO,2016,10(12):11344-11350.
APA	Hu, Minmin,Li, Zhaojin,Hu, Tao,Zhu, Shihao,Zhang, Chao,&Wang, Xiaohui.(2016).High-Capacitance Mechanism for Ti3C2TX MXene by in Situ Electrochemical Raman Spectroscopy Investigation.ACS NANO,10(12),11344-11350.
MLA	Hu, Minmin,et al."High-Capacitance Mechanism for Ti3C2TX MXene by in Situ Electrochemical Raman Spectroscopy Investigation".ACS NANO 10.12(2016):11344-11350.