Direct carbonization of rice husk to prepare porous carbon for supercapacitor applications

Searching low-cost porous carbon is crucial for the future development of supercapacitors in a wide application range. In this paper, rice husk derived carbon (RHC) was prepared through direct carbonization of rice husk in a tube furnace without inlet of N2. RHC possesses relatively high pore volume, specific surface area and specific capacitance. The high specific surface area of RHC is attributed to the self-activation of rice husk by H2O, CO2 produced in the carbonization process. RHC was further treated by alkali etching to prepare a porous carbon (referred as RHPC). Owing to the removing of SiO2 in RHC, RHPC exhibits higher specific surface area and specific capacitance than RHC.