Physico-chemical properties of biogenic SiO2 nanoparticles obtained from agriculture residue.

Plant-based biogenic silicon dioxide nanoparticles are used to produce catalysts, additives, templates for deposition of other semiconductors and metals, nanomaterials with novel properties, bio-nanocomposites for biomedical, energy and environmental fields. There are too many ways of bio-SiO₂ production. Dependent on the way and obtaining condition some properties of the plant-based biogenic silicon dioxide nanoparticles can be changed. The most amount of silicon is accumulated in stalks and husk biomass of rice, buckwheat and oats. The aim of our work was the investigation of physic-chemical properties of the biogenic silicon dioxide obtained from the rice husk by both ecologically- and economically-friendly technology. The fluoric technology was used for silicon dioxide isolation. Our technology allows us to restore used catalysts. Thus this technology is ecologically and economically efficient. The synthesised SiO₂ was studied by using the following methods: low-temperature nitrogen sorption–desorption, XRD, XRF, ICP-MS, AFM, FTIR-ATR, SEM-EDS, TGA. It was established that obtained samples had a specific surface area 107 m²/g. The XRD of the powdered SiO₂ showed 100% amorphous characteristics of the material. FTIR, XRF SEM-EDS, ICP-MS and X-ray diffraction indicated that samples contain only SiO₂. AFM results show obtained silica particles were having shape from spherical to lamellar. According to SEM investigated sample consists of spherical small aggregates. [ABSTRACT FROM AUTHOR]