Low-dimensional carbon nanomaterials: Characterization and application

This thesis focuses on two low dimensional carbon nanomaterials, namely carbon nanotubes, which are usually considered as one-dimensional, and higher fullerenes and their metal adducts, which can be regarded as zero-dimensional.; Chapter 1 outlines the general features of sp{dollar}sp2{dollar} carbon materials. The main techniques employed in this study are briefly introduced. The main objectives of this thesis are summarized.; Chapter 2 to 6 present the systematic study of carbon nanotubes (CNT). Chapter 2 gives the study of CNT by Raman scattering. We found that both singlewall and multiwall nanotubes display the similar Raman features as expected from their common curved tubular structure. A new dispersion phenomenon, an observation not predicted by theory, has been observed in the Raman spectra of both singlewall and multiwall nanotubes with respect to that of graphite.; Chapter 3 presents a comparison study of various sp{dollar}sp2{dollar} carbon materials. The dependence of the Raman features on the microscopic structure has been found. The physical meaning of 2G and 2D{dollar}spprime{dollar} bands has been further elaborated in the present study. The relative intensities of both bands can be used to judge quality of three dimensional stacking of graphitic layers.; Chapter 4 studies the electrochemical behavior of nanotubes in concentrated perchloric acid. The electrochemical behavior of CNT is different from that of graphite.; Chapter 5 summarizes our observation of nanotubes at various crystallization stages. Three types of carbon nanotubes, the well-graphitized, poorly-graphitized and non-graphitized, have been observed in the same arc-discharged product. A four-step model is proposed to account for the growth mechanism of the graphitized multiwall nanotubes.; Chapter 6 presents our exploration of the chemical applications of CNT. Nanofiber-like LiCoO{dollar}sb2{dollar} is synthesized at a low temperature (400{dollar}spcirc{dollar}C, in air) by using multiwalled carbon nanotube as the template. The templating process is accomplished in two possible manners: the coating and the filling processes, respectively.; Chapters 7 and 8 present the study of higher fullerenes and their adducts with rare-earth metals by means of electrochemical methods. The electrochemical properties of three higher fullerenes C{dollar}rmsb{lcub}86{rcub}, Csb{lcub}90{rcub}{dollar} and C{dollar}sb{lcub}92{rcub}{dollar} are summarized in chapter 7.; Chapter 8 summarizes the study of seven 4f-block metallofullerenes M@C{dollar}sb{lcub}82{rcub},{dollar} where M = Pr, Nd, Tb, Dy, Ho, Er and Lu, by CV and DPV. The first oxidation and the first reduction potentials of all seven M@C{dollar}sb{lcub}82{rcub}{dollar} were found to locate within a close vicinity to each other, suggesting that all the entrapped metals adopt a similar valence state, presumably a trivalent cation. Despite the proximity of the first oxidation and reduction potentials among different M@C{dollar}sb{lcub}82{rcub},{dollar} the subtle but visible variation caused by the different metals does exist. (Abstract shortened by UMI.)...