Synthesis of Porous Carbon for Acetone Adsorption: Specific Surface Area, Porous Structure and Oxygen Functional Groups

The porous carbon material is widely used as acetone adsorbent. The low-cost, facile and efficient synthesis method of porous carbon material is of great significance to the removal of acetone. Potassium citrate, a common organic salt, was self-activated in the current study at the temperatures of 600-900 degrees C to form porous carbons (KAC-X) with rich microporous structures. The KAC-X showed excellent specific surface area (763-2100 m(2) g(-1)) and oxygen content (5.95-16.29 wt%). The sample obtained at the temperature of 900 degrees C showed promising acetone adsorption capacities of 8.33 mmol g(-1) (15 degrees C) and 7.27 mmol g(-1) (25 degrees C), respectively. The acetone adsorption results were well fitted by the Langmuir-Freundlich and Freundlich models. Moreover, the influence of physical structure and oxygen functional group on the acetone adsorption performance was explored. The results showed that: (1) one of the main methods for promoting the acetone adsorption capacity is to increase the specific surface area; (2) the other method is to increase the optimal pore volume, and the optimal pore size is 2-5 times of the acetone molecule diameter; (3) carboxyl and carbonyl groups can significantly increase the adsorption affinity between acetone molecule and KAC-X, and play an auxiliary role on the acetone adsorption. This study provides guidance for the facile synthesis of porous carbons from organic salt for the sake of acetone adsorption.