title: Enhancing capacitive deionization technology as an effective method for water treatment using commercially available graphene.
abstract: In recent years, capacitive deionization (CDI) has been reported as one of the emerging technologies developed with the purpose of water desalination. This work is aimed at the integration of supercapacitor electrodes for efficient removal of ions from water, and thus to achieve an energy efficient, and cost-effective water treatment process. Our objective is to transfer the vast knowledge of supercapacitors and advanced materials in area of water treatment to enhance the knowledge of the CDI process. Towards the main purpose, graphene-based supercapacitor electrodes were developed from commercially available, cost-effective graphene and the use of these new materials for deionization was explored in detail. The porosity, morphology and electrochemical characteristics of the active materials were confirmed by Brunauer-Emmett-Teller method, scanning electron microscopy, Raman spectroscopy and chronoamperometry. Furthermore, the deionization performances of the graphene electrodes were evaluated by a laboratory scale CDI unit. The ion sorption behavior of the electrode was analyzed at different electrical potentials and flow rates. Impact of operating parameters on the sorption capacity was determined. At 20 mL/min flow rate and 2.0 V potential, the electrosorptive capacity of commercially available graphene electrodes could reach 12.5 μmol/g. Our results indicated the ability to use commercially available graphene for deionization purpose.
authors.affiliation: Department of Environmental Engineering, Middle East Technical University, Dumlupınar Blvd No. 1, Ankara 06800, Turkey E-mail: dderya@metu.edu.tr.
authors.forename: Derya
authors.initials: D
authors.lastname: Dursun
authors.affiliation: Department of Environmental Engineering, Middle East Technical University, Dumlupınar Blvd No. 1, Ankara 06800, Turkey E-mail: dderya@metu.edu.tr.
authors.forename: Selin
authors.initials: S
authors.lastname: Ozkul
authors.affiliation: Department of Micro and Nanotechnology, Middle East Technical University, Ankara 06800, Turkey.
authors.forename: Recep
authors.initials: R
authors.lastname: Yuksel
authors.affiliation: Department of Micro and Nanotechnology, Middle East Technical University, Ankara 06800, Turkey; Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06800, Turkey.
authors.forename: Husnu Emrah
authors.initials: HE
authors.lastname: Unalan
mesh_terms: D004560:Electricity; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D016062:Porosity; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D007477:Ions; D012965:Sodium Chloride; D006108:Graphite