Rapid sonochemical synthesis of spherical silica nanoparticles derived from brown rice husk

Abstract The nanoparticles of silica (SiO 2 ) were synthesized from brown rice husk via the sonochemical process, during which the sonication time was varied from 0 to 50 min so as to modulate the material properties of the nanoparticles. The synthesized SiO 2 nanoparticles were confirmed to have amorphous natures in their structural characteristics. The mean particle sizes of the nanoparticles were increased from 5 to 40 nm with increasing sonication time from 0 to 50 min, respectively. The SiO 2 nanoparticles synthesized with the sonication time of 50 min showed to possess the highest porosity among our samples. Accordingly, the sample exhibited a higher effective surface area of 271.22 m 2 g −1 . In addition, the bandgap of the SiO 2 nanoparticles was decreased from 5.77 to 5.68 eV with increasing sonication time ( i.e. , 0 → 50 min). The results suggest that the SiO 2 nanoparticles synthesized with an appropriate control of the sonication time ( e.g. , 50 min) hold promise for future nano-ecosystem applications such as nano-biosensors and energy storage nano-devices.