Colloidal crystal-templated porous carbon as a high performance electrical double-layer capacitor material

Bimodal porous carbons with both micropores and meso- or macropores were selectively synthesized by an SiO2 colloidal crystal-templating process. The SiO2 opal templates exclusively contributed to the formation of meso- and macropores in carbons. The electrical double-layer capacitance per surface area of the templated porous carbons was much larger than those of commercially available activated carbons with high surface areas. The surface of meso- and macropores generated in the porous carbons shows a highly efficient electrical double-layer capacitive property; the specific capacitance per surface area originating from meso- and/or macropores was estimated to be 20 +/- 2 muF cm(-2). (C) 2004 The Electrochemical Society.