Purification of single-wall carbon nanotubes by electrochemical oxidation

IMR OpenIR

	Purification of single-wall carbon nanotubes by electrochemical oxidation
	H. T. Fang; C. G. Liu; L. Chang; L. Feng; L. Min; H. M. Cheng
	2004
发表期刊	Chemistry of Materials
ISSN	0897-4756
卷号	16 期号:26 页码:5744-5750
摘要	The electrochemical cyclic voltammetric (CV) oxidation behavior of an arc-derived single-wall carbon nanotube (SWNT) sample in potassium hydroxide solution was investigated. Amorphous carbon in the as-grown SWNT sample was effectively removed by the CV oxidation, as confirmed by analyzing the sp(3)/sp(2) carbon ratio from C1s XPS spectra and HRTEM observations. The removal of the amorphous carbon led to the exposure of metal nanoparticles, hence facilitating the elimination of the metal impurities by subsequent HCl washing. The CV oxidation can be applied as an alternative oxidative treatment for the purification of SWNT samples. Redox peaks were observed during the CV oxidation. The reduction peaks in the range of -0.96 to -1.0 V and the oxidation peaks in the range of -0.61 to -0.49 V were attributed to the electrochemical redox transformations between metallic Fe and Fe(II) oxide, Fe(II) oxide and Fe(III) oxide, as well as Ni and Ni(II) oxide, and the observed reduction peaks in the potential range of 0.29-0.13 V were believed to be caused by the electrochemical reduction of NiOOH into Ni(OH)(2). The intensity of all of the redox peaks was dependent on the cycle number because more and more metal nanoparticles could be exposed as a result of the incremental removal or damage of the amorphous carbon coating during the CV oxidation, while the intensity remained almost unchanged after 80 cycles because of the completion of the amorphous carbon removal. Therefore, the redox peaks from the electrochemical redox reactions of Fe and Ni impurities can be considered as a benchmark for the removal extent of the amorphous carbon, and optimal electrochemical oxidation time for the purification of the as-grown SWNT sample can be determined in real time during the CV oxidation treatment. This is a predominant advantage of the CV oxidation over common oxidation methods using air or other oxidizing reagents for SWNT purification.
部门归属	chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. harbin inst technol, mat sci & engn sch, harbin 150001, peoples r china.;cheng, hm (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china;cheng@imr.ac.cn
关键词	Room-temperature Nickel Electrode Hydrogen Storage Functionalization Intercalation Particles Bundles Energy Swnts
URL	查看原文
WOS记录号	WOS:000225908600033
引用统计	被引频次：145[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/321006/35356
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	H. T. Fang,C. G. Liu,L. Chang,et al. Purification of single-wall carbon nanotubes by electrochemical oxidation[J]. Chemistry of Materials,2004,16(26):5744-5750.
APA	H. T. Fang,C. G. Liu,L. Chang,L. Feng,L. Min,&H. M. Cheng.(2004).Purification of single-wall carbon nanotubes by electrochemical oxidation.Chemistry of Materials,16(26),5744-5750.
MLA	H. T. Fang,et al."Purification of single-wall carbon nanotubes by electrochemical oxidation".Chemistry of Materials 16.26(2004):5744-5750.