Synthesis and characterization of cotton-made activated carbon fiber and its adsorption of methylene blue in water treatment

Activated carbon fiber (ACF) was fabricated by annealing and activating cotton with ZnCl2 in argon. We found that the cotton became microporous ACF, and it retained the original fibrous structure of cotton. Its BET surface area was up to 2060 m2 g−1. The Fourier Transform Infrared Spectrometry confirmed that it possessed a large number of oxygen functional groups. The adsorption capacity of this ACF product was evaluated in its adsorption of methylene blue (MB) in water under different pH values. We found that the adsorption process was well described by both the Langmuir isotherm model and the pseudo second order kinetics model. The ACF sample was effective in adsorbing MB in the neutral and alkaline conditions. The monolayer capacity for MB was up to 597 mg g−1 and was one of the highest among similar activated carbon product. It was due to its large BET surface area.

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► Synthesis of a cotton-based type activated carbon fiber by ZnCl2 activation.
► The original fibrous structure of raw cotton was retained in the ACF product.
► High BET specific surface area of 2060 m2 g−1 was obtained.
► A large number of oxygen functional groups were found on the surface of the ACF.
► Methylene blue adsorption capacity of our ACF product was up to 597 mg g−1.