Simultaneous preparation of silica and activated carbon from rice husk ash

Silica and activated carbon were simultaneously produced from rice husk ash with K2CO3. The surface area and average pore size of the activated carbon were 1713 m2/g and 4 nm. The maximum adsorption capacity of activated carbon was 210 mg/g for methylene blue and the capacitance value reached 190 F/g. The yield of silica reached 96.84% and the particle size was 40–50 nm. Potassium carbonate could be recycled. The entire synthetic procedure was simple, environmental-friendly and economical-effectively.