title: Enhanced Salt Removal in an Inverted Capacitive Deionization Cell Using Amine Modified Microporous Carbon Cathodes.
abstract: Microporous SpectraCarb carbon cloth was treated using nitric acid to enhance negative surface charges of COO(-) in a neutral solution. This acid-treated carbon was further modified by ethylenediamine to attach -NH2 surface functional groups, resulting in positive surface charges of -NH3(+) via pronation in a neutral solution. Through multiple characterizations, in comparison to pristine SpectraCarb carbon, amine-treated SpectraCarb carbon displays a decreased potential of zero charge but an increased point of zero charge, which is opposed to the effect obtained for acid-treated SpectraCarb carbon. An inverted capacitive deionization cell was constructed using amine-treated cathodes and acid-treated anodes, where the cathode is the negatively polarized electrode and the anode is the positively polarized electrode. Constant-voltage switching operation using NaCl solution showed that the salt removal capacity was approximately 5.3 mg g(-1) at a maximum working voltage of 1.1/0 V, which is an expansion in both the salt capacity and potential window from previous i-CDI results demonstrated for carbon xerogel materials. This improved performance is accounted for by the enlarged cathodic working voltage window through ethylenediamine-derived functional groups, and the enhanced microporosity of the SpectraCarb electrodes for salt adsorption. These results expand the use of i-CDI for efficient desalination applications.
authors: Center for Applied Energy Research, University of Kentucky , Lexington, Kentucky 40511, United States.
authors: Xin
authors: X
authors: Gao
authors: Center for Applied Energy Research, University of Kentucky , Lexington, Kentucky 40511, United States.
authors: Ayokunle
authors: A
authors: Omosebi
authors: Center for Applied Energy Research, University of Kentucky , Lexington, Kentucky 40511, United States.
authors: James
authors: J
authors: Landon
authors: Center for Applied Energy Research, University of Kentucky , Lexington, Kentucky 40511, United States.|Department of Mechanical Engineering, University of Kentucky , Lexington, Kentucky 40506, United States.
authors: Kunlei
authors: K
authors: Liu
mesh_terms: D000327:Adsorption; D000588:Amines / Q000737:chemistry; D002244:Carbon; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D017942:Nitric Acid / Q000737:chemistry; D012965:Sodium Chloride / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
chemical_list: D000588:Amines; D017942:Nitric Acid; D012965:Sodium Chloride; D002244:Carbon