Morphological characteristics of silica nanoparticles derived from rice husk for expected agricultural application

The study aimed to apply biosilica nanoparticles from renewable resources for improving soil quality as a type of fertilizer carier. The silica particles having a purity of about 98 % were extracted from rice husk at the calcination temperatures of 550 degrees C, 600 degrees C, 650 degrees C, and 700 degrees C. The required materials properties were investigated by advanced measurement techniques. All samples showed the amorphous structure with Si-O-Si bond and the particles' agglomeration with the average size of 10-50 nm and principle electronic structures with the typical spectra of Si and O-2. When the synthesized silica was used as the medium to release absorbed nutrients in a controlled manner, surface properties, including the Brunauer-Emmett-Teller area and the average pore diameter were evaluated between 179 m(2)/g to 570 m(2)/g, and 4 nm-40 nm, respectively. The measured electrokinetic potential of the synthesized particles was between -20 mV and -36 mV guaranteeing the stability when they are dispersed in the aqueous environment. The experimental results showed that the silica particles calcinated at 650 degrees C had the best properties.