Effective desalination by capacitive deionization with functional graphene nanocomposite as novel electrode material

In this work, functional graphene nanocomposite (reduced graphite oxidate‐resol like material, named RGO-RF) was successfully synthesized and used as electrode in capacitive deionization (CDI) process. The porosity, morphology and electrochemical characteristics of RGO-RF were confirmed by N2 adsorption–desorption curve, transmission electron microscopy and cyclic voltammetry, respectively. Further, the deionization performances of the RGO-RF electrode, reduced graphite oxidate (RGO) and activated carbon (AC) were examined for comparison by a lab-scale CDI experimental system. It is found that the RGO-RF shows the best deionization performance among the three target materials, indicating that it is a novel electrode material which has a great potential as effective electrode for CDI. Besides, the electrosorption isotherms and electrosorption kinetics were studied, and it is found that the ion sorption behaviour of RGO-RF follows a Langmuir adsorption isotherm, implying monolayer adsorption.

► The RGO‐RF nanocomposite obtained as electrode in CDI for desalination
► The introduction of resol prevents the aggregation reaction of the graphene nanosheets.
► Resol can significantly improve the electrical performance and desalination properties.
► The RGO‐RF nanocomposite electrode shows the best desalination properties among RGO, AC and RGO-RF.