KOH activation of ordered mesoporous carbons prepared by a soft-templating method and their enhanced electrochemical properties

Abstract

Ordered mesoporous carbon (COU-2) was synthesized by a soft-templating method. The COU-2 mesoporous carbon was activated by using KOH to improve its porosity. The mesopore size of COU-2 was 5.5nm and did not change by the KOH activation. But, the BET surface area of COU-2 largely increased from 694 to 1685m2/g and total pore volume was increased from 0.54 to 0.94cm3/g after the KOH activation. The large increase of micropore volume is due to the increase of the surface area. Electrochemical cyclic voltammetry measurements were conducted in aqueous (1M sulfuric acid) and organic (1M tetraethyl ammonium tetrafluoroborate/polypropylene carbonate) electrolyte solutions. The KOH-activated COU-2 carbon shows superior capacitances over the COU-2 carbon and a commercial microporous carbon both in aqueous and organic electrolyte solutions. These results suggest that the carbons having regularly-interconnected uniform mesopores and micropores in thin pore walls are desirable for the electrodes in electrochemical double-layer capacitors.