IN-SITU FORMATION OF AGCL NANOCRYSTALLITES IN FILMS PREPARED BY THE SOL-GEL AND SILVER NANOPARTICLES IN SILICA GLASS-FILMS

We are reporting on a novel preparation of silver chloride in sol-gel silica films as a precursor for nanoparticles of silver. The precipita tion of silver chloride particles in-situ was achieved by the reaction of silver nitrate with trichloroacetic acid. The reaction leads to a slow release of chloride leading to a controlled precipitation of AgCl . The existence of an isotropic crystalline AgCl phase in the glass fi lms was demonstrated by X-rays Diffraction Analysis (XRD) and Scanning Electron Microscope and Energy Dispersive Analysis of X-rays (SEM-EDA X). The resulting films are of good optical quality and exhibit a stro ng coloration upon irradiation with sunlight or heating to 600 degrees C, due to the reduction of AgCl to silver nanoparticles. The absorpti on spectra of the films before and after irradiation are shown.