Effect of heat treatment on CO₂ adsorption of KOH-activated graphite nanofibers

In this work, graphite nanofibers (GNFs) were successfully expanded intercalating KOH followed by heat treatment in the temperature range of 700-1000°C. The aim was to improve the CO₂ adsorption capacity of the GNFs by increasing the porosity of GNFs. The effects of heat treatment on the pore structures of GNFs were investigated by N₂ full isotherms, XRD, SEM, and TEM. The CO₂ adsorption capacity was measured by CO₂ isothermal adsorption at 25°C and 1atm. From the results, it was found that the activation temperature had a major influence on CO₂ adsorption capacity and textural properties of GNFs. The specific surface area, total pore volume, and mesopore volume of the GNFs increased after heat treatment. The CO₂ adsorption isotherms showed that G-900 exhibited the best CO₂ adsorption capacity with 59.2mg/g.