An asymmetrical activated carbon electrode configuration for increased pore utilization in a membrane-assisted capacitive deionization system

作者：Kim Jiyoung; Peck Dong Hyun; Lee Byungrok; Yoon Seong Ho; Jung Doo Hwan^*

来源：New Carbon Materials, 2016, 31(4): 378-385.

DOI：10.1016/j.carbon.2016.08.064

• Capacitive deionization
• Activated carbon fiber
• Pore size
• Sodium and chloride ions
• Asymmetric electrode

A membrane-assisted capacitive deionization (CDI) system was developed for the purification of water containing sodium chloride using activated carbon fibers (ACFs) as capacitor electrode materials. The ACFs have different degrees of activation with different surface areas and pore size distributions. Their desalination performance for sodium or chloride ions was investigated. Results indicate that the salt removal efficiency and surface area-normalized electrosorption capacity for each ion depend on the surface area, pore depth and the match between the pore sizes of the ACFs and the radius of each hydrated ion. A high surface area and shallow pores favor the salt removal efficiency and a high surface area-normalized electrosorption capacity. The ACS' with a median pore size of 0.69 nm performs best for sodium ion removal and those with median pore sizes of 1.09 and 1.52 nm are best for chloride ion removal, which could be ascribed to the fact that the radius of a hydrated sodium ion (0.66 nm) is smaller than that of a hydrated chloride ion (0.72 nm). An asymmetric electrode material configuration is needed to optimize both the anion and cation adsorption in the membrane-assisted CDI system.

• 出版日期2016-8