In situ SiO 2 etching strategy to prepare rice husk-derived porous carbons for supercapacitor application

A simple, effective, and scalable mix and pyrolysis process was developed for preparing rice husk-derived porous carbon. The process involves only mixing and pyrolyzing of carbon–silica composites (product of pre-carbonized rice husk) and Polytetrafluoroethylene (PTFE) powders under inert atmosphere to form porous carbon materials without any SiO2 residue. The fabrication process does not use any toxic or corrosive solution to etch the SiO2, which was more suitable for large scale production. The obtained porous carbon was endowed a desirable specific surface area (1550 m2/g) and porous structure with high mesoporosity of 52%. Electrochemical investigation measurements showed that the obtained porous carbon represents a good electrode candidate for supercapacitor, which displayed a high specific capacitance of 220 F/g at a current density of 0.5 A/g. In addition, the electrode displayed excellent cycling stability with a capacitance retention of about 98% over 10,000 cycles.