Synthesis and Electrochemical Characterization of RuO2•xH2O/Graphite Nanosheet Composite Array Electrodes for Supercapacitors

We used electrochemical exfoliation to construct graphite nanosheet (GNS) arrays, in which the varying number of nanosheet layers were parallel to each other and perpendicular to the carbon substrate. Hydrous ruthenium oxide (RuO2 center dot xH(2)O) was then loaded directly on the surface of nanosheets using cathodic reduction electrodeposition, resulting in the formation of RuO2 center dot xH(2)O/GNS composite array electrodes. Electrochemical measurements showed that the composite array electrodes exhibited excellent capacitive behaviors, and achieved specific capacitance values as high as 4226 F.m(-2) in the potential window up to 0.9 V, with a scan rate of 5 mV.s(-1) in 0.5 mol.L-1 H2SO4 solution. The RuO2 center dot xH(2)O/GNS composite array electrodes showed good cycling abilities, and maintained 94.18% of their maximum performance after 20000 cycles.