Activated nitrogen doped carbons (a-NCs) with microporous texture, tunable N doping level and forms were synthesized by carbonization and controllable alkali activation of polyaniline (PANT) precursor, which were further employed as electrode materials of supercapacitors and heterogeneous catalysts for 4-nitrophenol hydrogenation. Experimental results show that the activation temperature plays a crucial role on the specific surface area, N doping level and forms, graphitization degree and therefore the capacitive performance and catalytic activity of the afforded a-NCs, thus allow us to facilely tune the application performances as required. By activation at lower temperature (600 degrees C), the afforded a-NC600 maintains high N and O contents, high fraction of pseudocapacitance active species as well as considerable surface area, all of which result in the maximized specific capacitance (309 F g(-1) at current density of 1 A g(-1) in acidic electrolyte). In contrast, the sample activated at 800 degrees C, labeled as a-NC800, demonstrates high surface area and increased graphitic N, thus can offer preferential heterogeneous catalytic activity for 4-nitrophenol hydrogenation reaction. (C) 2015 Elsevier Ltd. All rights reserved.