Synthesis of ordered mesoporous carbons by Teflon-assisted removal of silica template in tri-constituent co-assembly for supercapacitors

Abstract

The synthesis of mesoporous carbon through tri-constituent co-assembly by introduction of silica as supporting is amenable to improve the surface area and porosity. However, this is a multistep process along with contamination from the use of toxic HF solution to remove the silica template. Herein, a “green” and one-pot method is demonstrated to prepare ordered mesoporous carbon with high surface area (1160 m2 g−1) by direct addition of Teflon into tri-constituent phases (including soft template, carbon, and silica source) for co-assembly and followed by pyrolysis. During the high-temperature treatment, the removal of soft template and silica support (can fast reacts with Teflon) and carbonization process are simultaneously accomplished to yield the carbon product with hierarchically porous structure including bimodal mesopores centered at 2.4 and 4.5 nm and abundant micropores. The resulting mesoporous carbon demonstrates an excellent electrochemical performance of 186 F g−1 at a discharge current of 1 A g−1 in 6 M NaOH. It can be attributed to both the hierarchically microporous/mesoporous structure and high surface area allowing the efficient transportation of ions into the carbon matrix. This mesoporous carbon also exhibits a good cycling stability with capacitance retention of ~ 97% over 5000 cycles.