Abstract
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.
•Direct carbonization method was used to prepare rice husk-based carbon (RHC).•This direct carbonization method is of low-cost due to the absence of activation.•RHPC with higher specific surface area was prepared from RHC by removing SiO2.•RHPC exhibits high specific capacitance and good rate capability.