A novel route for preparation of high-performance porous carbons from hydrochars by KOH activation

In the present work, a sustainable route to prepare high-performance porous carbons from hydrochars by KOH activation was described. The hydrochars was obtained from sulfuric acid hydrolyzate of rice husk via dehydration, polymerization and carbonization. When the pretreated hydrochars (42%) was activated at 400 °C for 0.5 h and 800 °C for 1 h with the mass ratio of KOH/hydrochars of 5:1, the high specific surface area and large pore volume of the porous carbons reached 3362 m2/g and 2.20 cm3/g, respectively. The specific capacitance of 312 F/g was achieved using this product, which indicated the porous carbon had good electrochemical performance. Furthermore, the X-ray diffraction pattern and Raman spectroscopy showed the porous carbon had localized graphitic structure.