Preparation of hierarchically porous carbon nanofoams for electrode materials of supercapacitors

Hierarchically porous carbon nanofoams (CNFs) with uniform cavity and highly porous skeleton have been prepared via the formation of core–shell organosilica nanoparticles in one-pot reaction and subsequent Friedel–Crafts chemistry. The porosity of the CNFs, which have macroporous cavity (∼50 nm), mesoporous windows (∼12 nm) between adjacent cavities and mesoporous skeleton (∼3 nm), were facially tuned by varying the amount of phenyltriethoxysilane (PTES) used in the first step. CNFs with high surface area (>1100 m2 g−1), large pore volume (∼2 cm3 g−1) and partially graphitized skeleton exhibited good performances as supercapacitor electrode materials. The specific capacitance of the porous CNFs reached 170 F g−1 at a current density of 0.5 A g−1 in an aqueous electrolyte.