Title: Carbon dioxide adsorption on nano/micro-scale porous adsorbents

Authors: Yu-Chun Chiang; Wei-Lien Hsu

Addresses: Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Rd., Chung-Li, Taoyuan 320, Taiwan ' Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Rd., Chung-Li, Taoyuan 320, Taiwan

Abstract: The objective of this paper is to investigate the physicochemical properties of the composites, carbon nanotubes (CNTs)/activated carbon fibres (ACFs), and determine the adsorption capacity of CO₂ on CNTs/ACFs. The chemical vapour deposition method was used for growth of CNTs without or with nitrogen doping. The spaghetti-like and a little randomly oriented CNTs with a high density and homogeneity were observed to grow onto the ACFs, while the morphology of nitrogen-doped CNTs on ACFs looked short, coarse and entangled. The result of high resolution of XPS N1s peak showed that the pyridine-type N and quaternary N were the predominant functional groups on all samples. Specifically, nitrogen-doped CNTs were characterised by the pyridine-like structures of six-member rings and hydrophobicity due to deficiency of oxygen atoms. The adsorption capacities of CO₂ on all samples decreased gradually as the temperature increased, implying the exothermic reaction on adsorption. The adsorption capacities of CO₂ based on surface areas at 25°C and 1 bar were between 1.60-2.69 µmole/m², and the ACFs grafted with nitrogen-doped CNTs exhibited the best performance for CO₂ adsorption.

Keywords: carbon adsorption; carbon dioxide; CO2; activated carbon fibres; ACFs; porous adsorbents; surface chemistry; adsorption capacity; nanoscale adsorbents; micro-scale adsorbents; nanotechnology; carbon nanotubes; CNTs; chemical vapour deposition; CVD; exothermic reaction; nitrogen doping; pyridine-like structures; hydrophobicity.

DOI: 10.1504/IJNM.2016.076150

International Journal of Nanomanufacturing, 2016 Vol.12 No.1, pp.1 - 14

Accepted: 04 Nov 2015
Published online: 27 Apr 2016 *

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