Rice Husk-Derived Mesoporous Silica Nanostructure for Supercapacitors Application: A Possible Approach for Recycling Bio-Waste into a Value-Added Product

We synthesized mesoporous SiO2 nanomatrix using rice husks as a precursor through a facile thermal combustion process. XRD, FTIR, EDX, and TEM analyses were used to validate the produced mesoporous SiO2 nanomatrix. Electrochemical measurements were used to determine the specific capacitance of mesoporous SiO2 nanomatrix, and the results showed that the specific capacitances are 216, 204, 182, 163, 152, 142, 135, 133, 124.4, 124 F/g at current densities of 0.5, 1, 2, 4, 6, 8, 10, 12, 14, and 16 A/g. The benefit of impurities, as well as the large surface area and mesoporous structure of rice husk derived SiO2 nanostructures, allow Faradaic redox reactions at the electrode surface and the resulting supercapacitive behavior. This research might lead to a low-cost technique of producing supercapacitor electrodes using rice husk-derived SiO2 as a precursor.