Preparation and characterization of nanosilica from sorghum husk ash by chemical method

Abstract

Extraction of nanosilica from Sorghum Husk Ash (SHA) was performed in this study by acid leaching method. Two methods of calcination was adopted (open and controlled method) in the production of SHA. Amorphous silica was produced by dissolving a quantity of SHA in hydrochloric acid solution which made the removal of heavy metals possible. The extracted/pure silica was rinsed with deionized water which lowers the pH to 7.0. The SHA silica was characterized using XRF, XRD and BET techniques. Silica and mineral contents of SHA were determined by XRF, while the X-ray diffraction patterns revealed the amorphous nature of extracted silica. Pure silica yield from SHA was 89.30%, while moisture content was 1.09%. The average particle size, BET surface area, pore volume, and pore diameter of SHA samples are 77.05 nm, 723.020 m2/g, 4.448e +01 cc/g, and 2.072e+00 nm respectively. The outcome of the research study reveals that the properties of the extracted silica satisfied all the requirements as established by relevant literature. Consequently, the high volume amorphous nanosilica with minimal mineral contaminants can be produced from SHA by the acid leaching method.