Highly porous carbons obtained by activation of polypyrrole/reduced graphene oxide as effective adsorbents for CO2, H2 and C6H6

Abstract

A series of highly porous carbon materials has been prepared from polypyrrole/reduced graphene oxide composite by one step carbonization and activation process. Two activation agents were used in this study potassium hydroxide and potassium citrate. The resulting samples exhibited high BET surface areas ranging from 1650 to 2780 m2/g, large total pore volumes in the range of 0.73–1.66 cm3/g, and high micropore volumes in the range of 0.43–0.78 cm3/g. The most porous material was synthesized by using KOH impregnation and featured hydrogen adsorption capacity of 11.3 mmol/g (2.3 wt% H2) at −196 °C under 760 mmHg and C6H6 capacity of 15.8 mmol/g at 20 °C and pressure close to the saturation vapor pressure. Also, highly ultramicroporous carbon was obtained by activation of the aforementioned composite with potassium citrate, which was confirmed by very high adsorption (6.8 mmol/g) of CO2 at 0 °C and 760 mmHg. The excellent adsorption properties of the synthesized carbons for CO2, H2 and benzene vapor were achieved by adjusting activation procedure specifically for each adsorbate used.