STRUCTURE AND PROPERTIES OF SILVER-SILICA COMPOSITE PREPARED FROM RICE HUSK SILICA AND SILVER NITRATE

Abstract

This research characterises the structure and physical properties of silver/silica (Ag/SiO2) composites using silver nitrate (AgNO3) and rice husk silica sols as precursors. The Ag/SiO2 composites were produced with different AgNO3 concentrations (0.3-0.8 M) heated to a temperature of 850 °C. All the composites were fully characterised in the solid state via various techniques; Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microcopy/ Energy Dispersive Spectroscopy (SEM/EDS), Thermal Gravimetry Analysis/Differential Thermal Analysis (TGA/DTA) were used to investigate the effects of changes in the sol concentration on the crystalline of Ag/SiO2 composites. In addition, a Particle Size Analysis (PSA) and a UV-visible technique were used to measure the particle size distribution and band gap energy, respectively. The X-ray diffraction (XRD) showed cristobalite and Ag face-centre-cubic (fcc) structures, indicating the deposition of the Ag particles on the SiO2 surfaces. The particle size distributions were found to be in a range of 0.01-0.42 µm and 0.49-3.43 µm, followed the band gap energies in a range of 1.97 to 2.17 eV, and 3.63 to 3.57 eV. As a result, the Ag/SiO2 composite promises to be a great biomedical material degrading high antibacterial properties.