Synthesis and Characterization of Ag/SiO₂ Nanocomposite Based on Rice Husk Silica Using Sol-Gel Method

Abstract

In this study, silver-silica (Ag/SiO2) was synthesized using the sol-gel method by silica from rice husks. Silica derived from rice husk waste was previously synthesized using the sol gel method. In addition, the Ag material used in this study was also performed into silver nanoparticles (AgNPs). This method was chosen to obtain an Ag/SiO2 composite with nano size and high purity. AgNPs were synthesized using silver nitrate (AgNO3) by reduction method at 90 °C. The reducing agent and stabilizer used is trisodium citrate. UV-Vis, FTIR, XRD, and SEM-EDX were used for the analysis Ag/SiO2 composites. Uv-Vis analysis results Ag/SiO2 has an absorption peak at a wavelength of 412 nm with a bandgap energy of 2.25 eV. These peaks indicate that AgNPs have formed in the SiO2 membrane. The FTIR results revealed the Si-O-Si bonds which indicated the presence of silica and the Ag-O functional group, and the presence of AgNPs. The results of XRD analysis showed that the silica structure formed was cristobalite and silver crystals in the face center cubic (fcc) shape. The results of the SEM-EDX morphological analysis showed that the Ag/SiO2 nanocomposite was shaped like sharp stone chips and the presence of small granules (granules) with different particle sizes and shapes, slightly porous and the composition of the compounds in the Ag/SiO2 nanocomposite indicated the presence of various chemical elements in the sample, including carbon, oxygen, sodium, silica, and silver.