An ultra-lightweight recyclable carbon aerogel from bleached softwood kraft pulp for efficient oil and organic absorption

A carbon aerogel with porous structure was synthesized from bleached softwood kraft pulp (BSKP) via eco-friendly freezing-drying and carbonization steps. The obtained carbon aerogel exhibited a low density of 25.5 mg cm(-3), high hydrophobicity with a water contact angle of 139.7 and good compressive properties. When used as an absorbent, the carbon aerogel could absorb 14 to 26 times its own weight in organic solvent and oil. Furthermore, the aerogel could be easily recovered and regenerated through burning, pressure recycling, and squeezing, and a high adsorption efficiency was maintained over a number of cycles. The use of biomass as a raw material, together with the excellent hydrophobicity and recyclability, make this carbon aerogel a suitable adsorbent for a variety of practical separation requirements. (C) 2018 Elsevier B.V. All rights reserved.