Carbon dioxide adsorption by modified carbon nanotubes

In this study the CO2 adsorption of three different diameters of multi‐walled carbon nanotubes (MWCNT) and single‐walled carbon nanotube (SWCNT) was investigated for a mixture of CO2/Ar at a temperature of 70 °C and atmospheric pressure. The largest diameter of MWCNT showed the highest CO2 uptake of 65.2 mg CO2 adsorbed per g adsorbent. One of the MWCNTs were modified with urea (CH4N2O) under two different loading durations with the aim of improving adsorption capacity. After such a functionalization, the CO2 uptake increased from 53.9 to 64.1 mg CO2 adsorbed per g adsorbent after 4 h loading duration. These findings indicate considerable potential of functionalized carbon nanotubes in comparison with other silica and carbon adsorbents.