Author
Xinyong Guo
Bio: Xinyong Guo is an academic researcher from Peking University. The author has contributed to research in topics: Carbon nanotube & Selective chemistry of single-walled nanotubes. The author has an hindex of 3, co-authored 3 publications receiving 1104 citations.
Papers
More filters
TL;DR: In this article, the effect of chemical oxidation on the structure of single-walled carbon nanotubes (SWNTs) by using different oxidants was investigated using infrared spectroscopy and transmission electron microscopy (TEM).
Abstract: In the present study, we report the systematic investigation of the effect of chemical oxidation on the structure of single-walled carbon nanotubes (SWNTs) by using different oxidants. The oxidation procedure was characterized by using infrared spectroscopy and transmission electron microscopy (TEM). The SWNTs were produced by chemical vapor deposition (CVD) and oxidized with three kinds of oxidants: (1) nitric acid (2.6 M), (2) a mixture of concentrated sulfuric acid (98 wt %) and concentrated nitric acid (16 M) (v/v = 3/1) and (3) KMnO4. The results reveal that the different functional groups can be introduced when the SWNTs are treated with different oxidants. Refluxing in dilute nitric acid can be considered as a mild oxidation for SWNTs, introducing the carboxylic acid groups only at those initial defects that already exist. The abundance of the carboxylic acid groups generated with this oxidant remained constant along with the treating time. In contrast, sonication of SWNTs in H2SO4/HNO3 increased ...
1,129 citations
TL;DR: In this article, the authors reported a simple way to enrich the large-diameter single-walled carbon nanotubes (SWNTs) by using a mixed concentrated H2SO4/HNO3 treatment.
Abstract: Herein we reported a simple way to enrich the large-diameter single-walled carbon nanotubes (SWNTs) by using a mixed concentrated H2SO4/HNO3 treatment. The proportion of the SWNTs with diameter larger than 2 nm measured from transmission electron microscopy was only ca. 3% in the original sample prepared by chemical vapor deposition method. It is found that this proportion becomes remarkably increased with treatment time and reached ca. 20% after 96 h of acid treatment.
24 citations
20 citations
Cited by
More filters
TL;DR: In this paper, a review of nitrogen-doped graphene is presented, including various synthesis methods to introduce N doping and various characterization techniques for the examination of various N bonding configurations.
Abstract: Nitrogen doping has been an effective way to tailor the properties of graphene and render its potential use for various applications. Three common bonding configurations are normally obtained when doping nitrogen into the graphene: pyridinic N, pyrrolic N, and graphitic N. This paper reviews nitrogen-doped graphene, including various synthesis methods to introduce N doping and various characterization techniques for the examination of various N bonding configurations. Potential applications of N-graphene are also reviewed on the basis of experimental and theoretical studies.
3,075 citations
TL;DR: A facile and scalable preparation of aqueous solutions of isolated, sparingly sulfonated graphene is reported, and NMR and FTIR spectra indicate that the bulk of the oxygen-containing functional groups was removed from graphene oxide.
Abstract: A facile and scalable preparation of aqueous solutions of isolated, sparingly sulfonated graphene is reported. 13C NMR and FTIR spectra indicate that the bulk of the oxygen-containing functional groups was removed from graphene oxide. The electrical conductivity of thin evaporated films of graphene (1250 S/m) relative to similarly prepared graphite (6120 S/m) implies that an extended conjugated sp2 network is restored in the water soluble graphene.
2,577 citations
TL;DR: In this article, the effect of oxidation on the structural integrity of multiwalled carbon nanotubes through acidic (nitric acid and a mixture of sulfuric acid and hydrogen peroxide) and basic (ammonium hydroxide/hydrogen peroxide), agents has been studied.
2,454 citations
TL;DR: In this article, the status of worldwide research in the thermal conductivity of carbon nanotubes and their polymer nanocomposites is reviewed, as well as the relationship between thermal conductivities and the micro- and nano-structure of the composites.
2,102 citations
TL;DR: In this paper, covalent modification schemes allow persistent alteration of the electronic properties of the tubes, as well as to chemically tailor their surface properties, whereby new functions can be implemented that cannot otherwise be acquired by pristine nanotubes.
Abstract: Since their discovery, carbon nanotubes have attracted the attention of many a scientist around the world. This extraordinary interest stems from their outstanding structural, mechanical, and electronic properties. In fact, apart from being the best and most easily available one-dimensional (1D) model system, carbon nanotubes show strong application potential in electronics, scanning probe microscopy, chemical and biological sensing, reinforced composite materials, and in many more areas. While some of the proposed applications remain still a far-off dream, others are close to technical realization. Recent advances in the development of reliable methods for the chemical functionalization of the nanotubes provide an additional impetus towards extending the scope of their application spectrum. In particular, covalent modification schemes allow persistent alteration of the electronic properties of the tubes, as well as to chemically tailor their surface properties, whereby new functions can be implemented that cannot otherwise be acquired by pristine nanotubes.
1,623 citations