Evaluation of the synthesis process for the extraction of silica from Sorghum vulgare seed heads

The isolation of nanosilica from agricultural waste aims to convert this waste into a valuable material. After the grains are removed, the Sorghum vulgare seed heads are categorized as agricultural biomass waste, serving as an economical source of silica raw material. This study focuses on extracting pure nanosilica from Sorghum vulgare seed heads. The seed heads were calcined at high temperatures to produce ash, and the organic material was eliminated. The resulting ash was subjected to three different chemical treatments: acid (acidification), base (precipitation), and oxidation (oxidizing agent) to remove the inorganic impurities. The isolated nanosilica was characterized using powder x–ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy‐dispersive x–ray spectroscopy. The transmission electron microscopy results indicate that the silica obtained is at the nanoscale. The x–ray diffraction pattern reveals that the silica extracted through the acidification and oxidation process are crystalline in nature, while the silica derived using the precipitation method is amorphous in nature. The Fourier transform infrared spectroscopy spectrum further confirms the presence of silica.