Synthesis of Three-dimensional Graphene Electrodes and Their Applications in Capacitive Deionization

In this paper, three-dimensional (3D) graphene hydrogel/aerogel were synthesized by wet chemistry methods, and then used as electrode materials in capacitive deionization(CDI) to separate NaCl from aqueous solution. Besides, the structure and character of the electrodes were analyzed by scanning electron microscopy, cyclic voltammetry, X-ray photoelectron spectroscopy and other methods. The results show that 3D graphene hydrogel has larger adsorption capacity than graphene aerogel. Then the graphene hydrogel electrode was optimized by pressing graphene hydrogel(pressing hydrogel). 3D graphene electrodes achieve good results in capacitive deionization. And the adsorption capacity ranking from big to small is pressing hydrogel, graphene hydrogel, graphene aerogel.