Biosilica Properties from Rice Husk using Various HCl Concentrations and Frequency Sources

Rice husk is a by-product of rice milling with more than 90% of silicon dioxide. The objective of this research was to characterize the purity and electricity as well as structure property and surface morphology of silicon dioxide depending on different concentration of chloride acid (HCl). The experimental consisted of leaching the rice husk using HCl solutions of 1%, 3%, and 5% for 2 hours and burning it at several annealing temperatures and times with temperature rate of 1 °C.min-1. The analysis included purity and morphology, structure property, and electricity of silicon dioxide using EDX-SEM, XRD, and LCR meter, respectively. The EDX measurement indicated that the higher the concentration of HCl, the higher the purity of silicon dioxide. Additionally, the higher the concentration of HCl led to the higher the electrical conductance, conductivity, and dielectric constant. While, the higher the frequency led to the higher the electrical conductance and conductivity but the lower the dielectric constant. Based on these electrical properties, silicon dioxide from rice husk can be applied as both an insulator and semiconductor materials on electronic devices.