Novel hybrid capacitive deionization constructed by redox-active covalent organic framework and its derived porous carbon for highly efficient desalination
Capacitive deionization (CDI) is a prospective cost-efficient technology for ion removal from brackish water. Development and design of new electrode materials with reasonable structure is of special importance for high performance CDI. Herein, redox-active covalent organic framework (COF) was first introduced and demonstrated as a novel faradaic cathode material for hybrid CDI (HCDI) application. Due to the high specific surface area and orderly distribution of redox unit, the COF presents a high capacitance of 170.9 F g-1 and typical pseudocapacitive characteristic. Moreover, N-doped porous carbon with high surface area and interconnected nanopores was synthesized from the same COF and used as anode in HCDI. The HCDI system demonstrates a highest salt removal capacity of 22.8 mg g-1 along with a maximum desalination rate of 3.2 mg g-1 s-1 in 500 ppm NaCl solution. The strategy in this work should provide a new insight in exploring high performance electrode materials for desalination application.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers