The ZnCl2 activated electrospun carbon nanofiber (Zn-AECNF) was fabricated by the electrospinning of polyacrylonitrile (PAN) nanofiber, followed by the preoxidation, carbonization and ZnCl2 post-treatment. The activated carbon nanofiber was characterized by scanning electron microscopy (SEM), contact angle, X-ray photoelectron spectroscopy, infrared spectroscopy and nitrogen adsorption. The carbon nanofiber obtained with ZnCl2 activation exhibits good flexibility, high hydrophilicity, and improved specific surface area. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated the enhanced capacitance and improved electric conductivity due to the treatment of ZnCl2. The Zn-AECNF was used for capacitive desalination successfully. With the higher ZnCl2 concentration used for carbon fiber impregnation, the specific surface area of the obtained carbon fiber was increased, and the desalination performance was enhanced accordingly. The salt adsorption of 10.52 mg/g was achieved when 60% ZnCl2 solution was used. The Zn-AECNF electrodes offer high potential for use in capacitive desalination technology. (C) 2014 Elsevier B.V. All rights reserved.