Direct preparation of activated carbon fiber aerogel via pyrolysis of cotton under CO₂ atmosphere and its adsorption of methylene blue

ABSTRACT

A novel activated carbon fiber aerogel (ACFA) was prepared in one step via pyrolysis of cotton under pure CO₂ atmosphere. The product was characterized by scanning electron microscope (SEM), N₂-adsorption/desorption, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The adsorption isotherms and kinetics of methylene blue (MB) by the product were elucidated. The experimental results demonstrated that ACFA had a twisted fibrous structure with a diameter of about 5 μm. The BET surface area and total pore volume of ACFA were up to 734 m² g^–1 and 0.428 cm³ g^–1, respectively. ACFA had a highly turbostratic graphite structure with many oxygen-containing functional groups on its surface. The adsorption equilibrium data could be represented by Langmuir isotherm model, showing a maximum monolayer adsorption capacity of 204 mg g^–1, and the kinetic data followed closely the pseudo-second-order kinetic model. The results proved that cotton could be a promising candidate for the preparation of ACFA with developed porous structure and high adsorption capacity.

KEYWORDS:

• Activated carbon fiber aerogel
• cotton
• CO₂ activation
• characterization
• adsorption

Additional information

Funding

This work was financially supported by Fundamental Research Funds for Central Public Welfare Scientific Research Institution (K-JBYWF-2017-T09) and National Key Research and Development Program of China (2016YFE0102400). The authors wish to thank the anonymous reviewers for their useful comments.