Preparation of carbon aerogels from TEMPO-oxidized cellulose nanofibers for organic solvents absorption

Abstract

In this study, ultralight and hydrophobic carbon aerogels were prepared from 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized cellulose nanofibers (TOCN) for the removal of organic solvents. The morphological structure, density and chemical composition of TOCN aerogels frozen at −56 °C and −196 °C, followed by pyrolysis, were examined. The obtained carbon-based aerogels possessed an ultralight density of 8.8 mg cm⁻³ and excellent fire-resistance. The high porosity (up to 99.5%) and hydrophobicity (contact angle of 139.6°) of the obtained carbon aerogels allowed them to adsorb various organic solvents with a high absorption capacity (up to 110–260 g g⁻¹). After five absorption–combustion and absorption–distillation cycles, the absorption capacity of the TOCN carbon aerogels exhibited excellent recyclability with up to 64–99% of the initial absorption capability, demonstrating potential applications in the oil-spill-cleanup field.