Synthesis of mesoporous carbon fibers with a high adsorption capacity for bulky dye molecules

Abstract

The mesoporous carbon fibers, of about 400 to 900 nm in diameter, have been synthesized by an electrospinning method with PF resin and PVP as carbon sources and triblock copolymer Pluronic P123 and tetraethyl orthosilicate (TEOS) as mesoporous templates. All materials have large surface areas (1215–2092 m² g⁻¹), high pore volumes (0.66–1.37 cm³ g⁻¹), and mesoporous structure (with pore sizes of 2.31–2.64, 3.79–3.86, and 5.68–5.70 nm). The adsorption capability of four dyes, methylthionine chloride, methyl orange, rhodamine B, and congo red have been investigated. All the adsorption isotherms fit the typical Langmuir adsorption model well. The mesoporous carbon fibers show high adsorption capacity for these bulky dye molecules. The adsorption amount is mainly determined by the surface area, pore size and the structure/size matching between adsorbent and adsorbate. With the highest BET surface area, C-3.5 (with 3.5 g TEOS) exhibits the highest adsorption amount (1044 mg g⁻¹).