STUDIES ON STRUCTURE AND PROPERTY OF CARBON-NANOTUBES FORMED CATALYTICALLY FROM DECOMPOSITION OF CH4 OR CO

Citation
P. Chen et al., STUDIES ON STRUCTURE AND PROPERTY OF CARBON-NANOTUBES FORMED CATALYTICALLY FROM DECOMPOSITION OF CH4 OR CO, Gaodeng xuexiao huaxue xuebao, 19(5), 1998, pp. 765-769
Citations number
13
Categorie Soggetti
Chemistry
ISSN journal
02510790
Volume
19
Issue
5
Year of publication
1998
Pages
765 - 769
Database
ISI
SICI code
0251-0790(1998)19:5<765:SOSAPO>2.0.ZU;2-O
Abstract
By means of TEM, HRTEM, XRD, XPS and TPO methods, structure and proper ties of the carbon-nanofibers formed catalytically from decomposition of CH4 or CO have been investigated. The TEM observation shows that th ese materials are,even nanotubes with the outer diameters of 15 simila r to 20 nm, Their XRD patterns are very close to that of graphite, but the XRD features are somewhat broadened, indicating that the degree o f long-range order of these nanostructures is relatively low in compar ison with that of graphite. HRTEM observation reveals that the wall of these nanotubes is constructed by many layers of carbon with graphite -like platelets in an extremely ordered arrangement, with the orientat ion of the conical graphite-like platelets inclined to the central axi s of the tube for the material produced from CH4 and the cylindrical g raphite-like platelets parallel to the tube-axis for that from CO, res pectively. XPS measurements show that C-1s electron binding energy in these carbon-nanotubes is about 0.5 eV lower than that of graphite. Th e results of the O-2-TPO testing demonstrate that content of amorphous carbon in these materials is very low, and then; the nanostructures a re entirely graphitic in nature; the TPO results also show that the te mperature for gasification of the material-produced from CH4 is about 100 K higher than that from CO, indicating that the former has a bette r oxygen-resistibility than the latter.