3D Channel-structured graphene as efficient electrodes for capacitive deionization

Capacitive deionization (CDI), which is one of up-and-coming water treatment technologies, is based on ion electrostatic adsorption on electrode surface. Herein, three-dimensional channel-structured graphene (CSG), which was synthesized via exothermic reaction between liquid potassium and carbon monoxide gas, was demonstrated as an efficient electrode material for CDI. Namely, the CSG electrode exhibited a specific capacity of 207.4 F/g at 0.2 A/g in 1 M NaCl aqueous solution. In a batch-mode recycling system, the electrosorption capacity of CSG can achieve 5.70 and 9.60 mg/g at 1.5 V in 50 and 295 mg/l NaCl aqueous solutions, respectively. The excellent electrosorption capacity of CSG, especially under low saline concentration, can be attributed to the synergistic effect of its large surface area (711.9 m(2)/g), unique channel structure, and oxygen functional groups. (C) 2018 Elsevier Inc. All rights reserved.