A novel two-staged thermal synthesis method of generating nanosilica from rice husk via pre-pyrolysis combined with calcination

Rice husk is a promising precursor for producing amorphous nanosilica particles. Nanosilica particles with controllable surface areas and pore volumes have been obtained from rice husk using a novel two-staged thermal method via pre-pyrolysis combined with calcination. Nanosilica particles of different levels of purity and textural properties were produced under CO2 and N2 pyrolysis atmosphere within the temperature range of 300-800 °C. The materials synthesized at the designated pyrolysis temperature were characterized to have a purity of 95.85-99.62%, a specific surface area of 204.3-352.6 m2/g, and a total pore volume of 0.3513-0.5228 cm3/g. The morphology and non-crystal structure of the particles was studied by transmission electron microscope and X-ray powder diffractometer. The controllable textural characteristics allow these particles to be used in several scientific and technological fields, where different levels of purity and textural properties are required.