The production of an electrochemical capacitor electrode using holey single-wall carbon nanohorns with high specific surface area

We prepared single-wall carbon nanohorns (SWCNHs) with a high specific surface area and fabricated an electrochemical capacitor electrode with good performance from them. Carbon impurities involved in the as-grown SWCNHs were thoroughly removed and the purified SWCNHs were oxidized to produce holes in them (SWCNHox). The specific surface area was estimated as 1720 m2/g, the largest surface area of SWCNHs ever reported. Capacitive properties were also investigated using the obtained SWCNHox. We found that an electrochemical device with SWCNHox showed an excellent specific capacitance of about 100 F/g, accelerating industrial progress for their uses in energy and environmental fields.