Surface Functional Groups and Interlayer Water Determine the Electrochemical Capacitance of Ti3C2Tx MXene

IMR OpenIR

	Surface Functional Groups and Interlayer Water Determine the Electrochemical Capacitance of Ti3C2Tx MXene
	Hu, MM; Hu, T; Li, ZJ; Yang, Y; Cheng, RF; Yang, JX; Cui, C; Wang, XH; Wang, XH (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China.
	2018-04-01
发表期刊	ACS NANO
ISSN	1936-0851
卷号	12 期号:4 页码:3578-3586
摘要	MXenes, an emerging class of conductive two-dimensional materials, have been regarded as promising candidates in the field of electrochemical energy storage. The electrochemical performance of their representative Ti3C2Tx, where T represents the surface termination group of F, O, or OH, strongly relies on termination mediated surface functionalization, but an in-depth understanding of the relationship between them remains unresolved. Here, we studied comprehensively the structural feature and electrochemical performance of two kinds of Ti3C2Tx MXenes obtained by etching the Ti3AlC2 precursor in aqueous HF solution at low concentration (6 mol/L) and high concentration of (15 mol/L). A significantly higher capacitance was recognized in a low-concentration HF-etched MXene (Ti3C2Tx-6M) electrode. In situ Raman spectroscopy and X-ray photoelectron spectroscopy demonstrate that Ti3C2Tx-6M has more components of the -O functional group. In combination with X-ray diffraction analysis, low-field H-1 nuclear magnetic resonance spectroscopy in terms of relaxation time unambiguously underlines that Ti3C2Tx-6M is capable of accommodating more high-mobility H2O molecules between the Ti3C2Tx interlayers, enabling more hydrogen ions to be more readily accessible to the active sites of Ti3C2Tx-6M. The two main key factors (i.e., high content of -O functional groups that are involved bonding/debonding-induced pseudocapacitance and more high-mobility water intercalated between the MXene interlayers) simultaneously account for the superior capacitance of the Ti3C2Tx-6M electrode. This study provides a guideline for the rational design and construction of high-capacitance MXene and MXene-based hybrid electrodes in aqueous electrolytes.; MXenes, an emerging class of conductive two-dimensional materials, have been regarded as promising candidates in the field of electrochemical energy storage. The electrochemical performance of their representative Ti3C2Tx, where T represents the surface termination group of F, O, or OH, strongly relies on termination mediated surface functionalization, but an in-depth understanding of the relationship between them remains unresolved. Here, we studied comprehensively the structural feature and electrochemical performance of two kinds of Ti3C2Tx MXenes obtained by etching the Ti3AlC2 precursor in aqueous HF solution at low concentration (6 mol/L) and high concentration of (15 mol/L). A significantly higher capacitance was recognized in a low-concentration HF-etched MXene (Ti3C2Tx-6M) electrode. In situ Raman spectroscopy and X-ray photoelectron spectroscopy demonstrate that Ti3C2Tx-6M has more components of the -O functional group. In combination with X-ray diffraction analysis, low-field H-1 nuclear magnetic resonance spectroscopy in terms of relaxation time unambiguously underlines that Ti3C2Tx-6M is capable of accommodating more high-mobility H2O molecules between the Ti3C2Tx interlayers, enabling more hydrogen ions to be more readily accessible to the active sites of Ti3C2Tx-6M. The two main key factors (i.e., high content of -O functional groups that are involved bonding/debonding-induced pseudocapacitance and more high-mobility water intercalated between the MXene interlayers) simultaneously account for the superior capacitance of the Ti3C2Tx-6M electrode. This study provides a guideline for the rational design and construction of high-capacitance MXene and MXene-based hybrid electrodes in aqueous electrolytes.
部门归属	[hu, minmin ; hu, tao ; li, zhaojin ; cheng, renfei ; yang, jinxing ; cui, cong ; wang, xiaohui] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, liaoning, peoples r china ; [hu, minmin ; cheng, renfei ; yang, jinxing ; cui, cong] univ sci & technol china, sch mat sci & engn, shenyang 110016, liaoning, peoples r china ; [hu, tao ; li, zhaojin] univ chinese acad sci, beijing 100049, peoples r china ; [yang, yi] suzhou niumag analyt instrument corp, suzhou 215163, peoples r china
关键词	2-dimensional Titanium Carbide High Volumetric Capacitance Nuclear-magnetic-resonance Energy-storage Charge Storage Intercalation Spectroscopy Electrodes Oxide Supercapacitors
学科领域	Chemistry, Multidisciplinary ; Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary
资助者	Youth Innovation Promotion Association; Chinese Academy of Sciences (CAS) [2011152]; Shenyang National Laboratory for Materials Science, Institute of Metal Research, CAS; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase) [U1501501]
收录类别	SCI
语种	英语
WOS记录号	WOS:000431088200055
引用统计	被引频次：345[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/79383
专题	中国科学院金属研究所
通讯作者	Wang, XH (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China.
推荐引用方式 GB/T 7714	Hu, MM,Hu, T,Li, ZJ,et al. Surface Functional Groups and Interlayer Water Determine the Electrochemical Capacitance of Ti3C2Tx MXene[J]. ACS NANO,2018,12(4):3578-3586.
APA	Hu, MM.,Hu, T.,Li, ZJ.,Yang, Y.,Cheng, RF.,...&Wang, XH .(2018).Surface Functional Groups and Interlayer Water Determine the Electrochemical Capacitance of Ti3C2Tx MXene.ACS NANO,12(4),3578-3586.
MLA	Hu, MM,et al."Surface Functional Groups and Interlayer Water Determine the Electrochemical Capacitance of Ti3C2Tx MXene".ACS NANO 12.4(2018):3578-3586.