Preparation of three-dimensional ordered mesoporous carbon sphere arrays by a two-step templating route and their application for supercapacitors

Abstract
A two-step template approach was demonstrated for preparation of the three-dimensional ordered mesoporous carbon sphere arrays. The ordered macroporous silica skeleton was formed from silicon alkoxide precursor templating around polystyrene (latex) spheres, and removal of the polystyrene spheres. These preforms as hard templates were infiltrated with a solution mixture of amphiphilic triblock copolymer PEO-PPO-PEO and soluble resol. By combining evaporation-induced surfactant-templating organic resol self-assembly with thermosetting, carbonization and hydrofluoric acid extraction of silica, the obtained mesoporous carbon has a pore size of 10.4 nm, interconnected window size of about 60 nm, surface area of 601 m2/g and pore volume of 1.70 cm3/g. The electrochemical properties as an electrode material for supercapacitor applications were investigated in nonaqueous electrolyte. They show rectangular-shaped cyclic voltammetry curves over a wide range of scan rates even up to 200 mV/s between 0 and 3 V, and deliver a large capacitance of 14 µF/cm2 (84 F/g), and good cycling stability with capacitance retention of 93% over 5000 cycles.