Nitrogen adsorption characterization of aligned multiwalled carbon nanotubes and their acid modification.
Aligned multiwalled carbon nanotube (CNT) arrays were synthesized by using an iron-based sol-gel catalyst and acetylene as the precursor. These CNTs show high purity, uniform diameters and pore-wall thickness. Low temperature nitrogen adsorption was employed to characterize the structural and surface properties of the as-synthesized sample and that modified with boiling concentrated nitric acid. The adsorption characteristics of the as-synthesized and modified CNTs were thoroughly investigated. High-resolution comparative alpha(s)-plot showed that the nitrogen adsorption on CNTs takes place via a multistage mechanism closely related to their structures. It was also found that the acid modification significantly increased the adsorption energy and enhanced the adsorption capacity under low pressures. High-resolution comparative method provided valuable insights about the surface and pore structures of CNTs.
Chemical Sciences Division, MS-6201, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
Zuojiang
Z
Li
Zhengwei
Z
Pan
Sheng
S
Dai
D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods; D017942:Nitric Acid / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D013499:Surface Properties
D017942:Nitric Acid; D002244:Carbon; D009584:Nitrogen