Raman spectroscopy and nitrogen vapour adsorption for the study of structural changes during purification of single-wall carbon nanotubes

Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

“…an increase of the tangential mode wavenumbers, are reported, e.g. for nitric acid treatments, 61,97,125,128,129,134,135 SOCl 2 treatment, 136,137 ozone oxidation, 60 oxidation by 130 upon solubilization of acidoxidized SWCNTs using SOCl 2 . Also, a downshift of the G-band was reported upon functionalization in ammonia plasma 103,138 and electrochemical nitration.…”

Adsorption of fluoride from aqueous solution by magnesia‐amended silicon dioxide granules

“…MAS exhibited a more pronounced slope in the range 0.5-0.9 p/p 0 , indicating a large external surface area. 28 The pore parameters of samples in Table 1 show the decrease of pore volume and pore size in MAS that indicates diffusion of magnesia takes place into the pores of the silicon dioxide. Both the pore volumes of MAS (4.34 cm 3 g −1 ) and SiO 2 (11.41 cm 3 g −1 ) correspond to mesopores.…”

Oxygen reduction reaction properties of carbon nanofibers: Effect of metal purification

“…The Raman spectroscopic parameters of CNFs treated by different methods are listed in Table 2 oxygen-containing groups introduced in chemical treatment. The decrease of I D /I G value in chemical treatment has been reported for CNTs [17,26]. For CNTs treated by HF solution, Lafi et al [26] concluded from compared the Raman spectra that the decrease of I D /I G value of the purified CNFs was a result of the increase in the degree of surface damage due to the introduction of function groups.…”

“…Lafi et al annealed the as-grown CNTs at 1000 • C in argon atmosphere to separate the metal impurities from CNTs [26]. Zhao et al [27] purified the as-grown CNFs by using a thermal method at the temperature of 1700 • C in argon atmosphere before investigate their catalytic performance in ethylbenzene oxidative dehydrogenation.…”