J. Electrochem. Sci. Technol. 6(4), 139-145 (2015) - 139 - Effect of Chemically Treated / Untreated Carbon Cloth: Poten- tial Use as Electrode Materials in the Capacitive Deionization Process of Desalination of Aqueous Salt Solution Annadurai Thamilselvan 1 , A Samson Nesaraj 2 * , Michael Noel 1 , and E.J. James 1 1 Water Research Laboratory, Water Institute, Karunya University, Coimbatore-641 114, Tamil Nadu , India 2 Department of Chemistry, School of Science and Humanities, Karunya University, Coimbatore-641 114, Tamil Nadu, India Abstract Capacitive deionization (CDI) process is a novel approach for desalination of an aqueous salt solution. In the present study, an activated carbon cloth (ACC) is proposed as effective electrode material. Initially the carbon cloth was activated in 1 M and 8 M HNO 3 for 9 hours at room temperature. The untreated and chemically activated carbon cloth (ACC) electrode materials were subjected to BET surface area measurements in order to get information about their specific surface area, average pore size, total pore volume and micropore area. The above materials were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) also. The electrochemical studies for the electrodes were done using cyclic voltammetry (CV) in 0.1 M Na 2 SO 4 medium. From the studies, it was found that resistivity of the activated carbon cloth electrodes (treated in 1 M and 8 M HNO 3 ) was decreased significantly by the chemical oxidation in nitric acid at room temperature and its capacitance was found to be 90 F/g (1 M HNO 3 ) and 154 F/g (8 M HNO 3 ) respectively in 0.1 M Na 2 SO 4 solution. The capacitive deionization behavior of a single cell CDI with activated carbon cloth electrodes was also studied and reported in this work. Keywords: Activated carbon cloth, capacitive deionization (CDI), desalination, chemical activation, cyclic voltammetry, chronocoulometry Received December 1, 2014 : Accepted February 2, 2015 1. Introduction Capacitive deionization (CDI) is one of the promis- ing energy efficient technologies for the desalination of water [1-2]. Adsorption of ions on to electrode sur- face during the introduction of electrical potential is a basic concept of CDI [3]. The electrosorption is a process in which a known potential is applied to an electrode of an electrochemical cell. As a result the inorganic ions present in the electrolyte moved to the electrical double layer (EDL) of the electrode sur- face and if the potential is removed, the ions are released back to the solution. This process operates at low cell voltages and hence it is more energy efficient than electrodialysis and even reverse osmosis when the low salt content feed is treated [4-6]. The expen- sive high surface area carbon aerogel electrodes are used at present in electrochemical treatment proce- dures and which is a major challenge to be tackled in order to make this process commercially viable [7-8]. *Corresponding author. Tel.: +091-422-2614301 E-mail address: drsamson@karunya.edu DOI: http://dx.doi.org/10.5229/JECST.2015.6.4.139 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativ ecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Research paper Journal of Electrochemical Science and Technology