polybasic acid-assisted sol-gel route to silica and ag-doped silica nanoparticies

ABSTRACT

Quasi regular silica nanoparticles are synthesized and post-treated for a facile homogeneous doping with metallic silver. The nanoparticles are obtained through a simple alkali-mediated sol-gel route in presence of tartaric acid and conventional ultrasonic agitation. Gelation in presence of both mechanical agitation and ultrasonic dispersion has lead to the formation of well-dispersed silica nanoparticles having an average particle size of less than 10 nm. In addition, tartaric acid was used to interfere in the hydrolysis stage that has lead to the formation of silica nanocubes probably by forming templates at the early stages of formation of the amorphous hydrous silica colloid. Unlike the acid hydrolysis route that produces irregular-shape grains or micro-sized agglomerates. TEM images in this study show that the combined application of tartaric acid template and ultrasonic agitation during gelation enhanced the formation of well dispersed silica nanocubes. XRD measurements showed that post-treatment of silica wet gel with metallic silver into the silica grains by sonication in silver ion solution and later reduction has successfully loaded the silica particles with silver to a good extent on the expense of regularity and dispersion of obtained nanoparticles. Samples were also characterized by FT-IR