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Keywords:

  • supercapacitors;
  • ordered mesoporous carbons;
  • pore structure

Abstract

In the present study, two mesoporous carbons OMC-KIT-6 and OMC-SBA-16 were nanocasted using mesoporous silica of KIT-6 and SBA-16 as templates and furfuryl alcohol as carbon precursor. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) characterizations confirmed that the resultant samples are mesoporous carbons, and the as-prepared OMC-KIT-6 has an Ia3d ordered structure, whereas OMC-SBA-16 belongs to Im3m space group. The surface area and the average pore size are (1658 m2 g−1 and 3.4 nm) for OMC-KIT-6 and (1638 m2 g−1 and 2.9 nm) for OMC-SBA-16, respectively. The results of cyclic voltammograms and galvanostatic charge-discharge tests show that these two mesoporous carbons have excellent capacitive performances. But the difference of capacitive behavior between OMC-KIT-6 and OMC-SBA-16 may be a result of the difference of pore geometries of these two carbons. In order to find out the function of mesopore in a supercapacitor, we compared the capacitive properties of mesoporous and microporous carbons; the experiment results indicated that these two kinds of carbon exhibit nearly ideal capacitive behavior at low scan rate. When the scan rate is enhanced up to 50 mV s−1 the performance of mesoporous carbon is more stable than microporous carbon. This outcome demonstrated that mesopore plays an important role in forming double layers in the electrode materials. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.