A graphitized carbide-derived carbon (CDC), synthesized by chlorination of TIC at 1000 degrees C, has high specific surface area (SSA), hierarchical micro- and meso-pores, and excellent electrical conductivity. However, the low hydrophilicity leads to poor supercapacitive in alkaline electrolyte. A strategy that introducing oxygen-containing functional groups onto the graphitized CDC by nitrate acid treatment is presented to improve its surface wettability. The treated CDC exhibits a great increase in specific capacitance (from 113 to 146 Fg(-1)) and, most interestingly, an enhanced power capability, a rectangular shape being maintained in CV curves even at the scan rate of 500 mV s(-1). The superiority of the treated CDC is caused by the improved wettability, maintained mesopores and high accessible SSA. Moreover, the introduction of oxygen-containing functional groups contributes the pseudocapacitance of graphitized CDC. Therefore, HNO3 treatment is a promising way to improve the supercapacitive performance of graphitized carbon materials with mesopores and high specific surface area. (C) 2015 Elsevier Ltd. All rights reserved.