Acidified Activated Carbon with Enhanced Electrochemical Performance for Supercapacitors

Abstract

Activated carbons carrying oxygen functional groups have been subjected to extensive research due to their potential applications in adsorption, sensors, catalysis, drug delivery, and energy storage/conversion systems.In this paper, acidified activated carbon (AAC) has been prepared through chemical oxidation of commercial activated carbon (AC) in a mild oxidation environment, providing AAC with enhanced concentration of single-graphene layers, improved degree of graphitization, reduced specific surface area and micropore volume, and a surface dominated by C=O/C-O groups.The electrochemical performance of AC and AAC is investigated in the role of electrode materials for supercapacitors in a three-electrode mode.Compared with AC, AAC exhibits an enlarged working potential window and superior electrochemical performance at current densities lower than 10 A g -1 .After 5000 cycles at 1 A g -1 , the specific capacity of AAC is retained at126.7 F g -1 , higher than that of 113.7 F g -1 for AC.