Ordered mesoporous carbon as an efficient and reversible adsorbent for the adsorption of fullerenes

Abstract

An ordered mesoporous carbon, CMK-3, was synthesized using mesoporous siliceous material, SBA-15, as the template. The CMK-3 was characterized and used for the adsorption of fullerenes, C 60 and C 70. It was found that the adsorption capacity of CMK-3 is four times higher than that of activated carbon (AC), while the other two adsorbents being investigated, alumina and silica gel, have little adsorption capacity for fullerenes. A detailed study was undertaken to determine the adsorption equilibrium isotherms of C 60 and C 70 on CMK-3 for both single and binary systems. The reversibility of fullerene adsorption on CMK-3 was also studied. It was found that nearly 24 % adsorbed C 60 and 8 % adsorbed C 70 can be desorbed from CMK-3 within 10 minutes at 25 □ when a volume of 200 ml pure toluene is used to desorb 25 mg of pre-saturated adsorbent in a batch desorption process. The effects of time, volume of toluene, and temperature on the desorption of fullerenes from CMK-3 were examined. It was shown that the volume of toluene and the temperature are two important factors for fullerenes, especially for C 70, to be desorbed from CMK-3. Increasing the volume and the temperature will help C 70 to be desorbed from CMK-3. The above results indicate that CMK-3 is an efficient and reversible adsorbent for the separation of fullerenes by adsorption.