Adsorption of phenol on supercritically activated carbon fibres: Effect of texture and surface chemistry

The influence of texture and surface chemistry on the phenol adsorption capacity of activated carbon fibres (ACFs) was studied. ACFs were prepared by carbonization of a phenolic textile fibre under nitrogen flow, followed by activation with H2O and CO2 (under atmospheric pressure and supercritical state). The materials were characterised by N2 and CO2 adsorption, and by temperature programmed desorption studies. A strong correlation between the amount of adsorbed phenol and the micropore volume has been observed. The relationship between surface oxygen concentration and amount of physisorbed and chemisorbed phenol was assessed, and it was shown that higher amounts of surface oxygen groups decreased the phenol chemisorption capacity of ACFs.

Graphical abstractThe amount of chemisorbed phenol over activated carbon fibres decreases with an increase in surface oxygen concentration.Figure optionsDownload full-size imageDownload high-quality image (55 K)Download as PowerPoint slideResearch highlights► Activation of carbon fibre by H2O or CO2 results in samples with different texture. ► Amount of adsorbed phenol increases with increase in volume of small micropores. ► Adsorption capacity decreases when large amounts of oxygen groups are introduced. ► Most of the phenol is adsorbed physically and nearly independent of surface oxygen. ► Amount of chemisorbed phenol decreases with increase in surface oxygen.