Ag/SiOx nanocomposite powders synthesized from colloids obtained by pulsed laser ablation

Abstract

Ag/SiOx nanopowders were obtained from Ag and Si/SiO2 colloids synthesized via pulsed laser ablation in water. The resulting composite powder was annealed at different temperatures in the region of 100–900 °C. The composition and structure of the obtained materials were studied. The interaction between silica and silver species taking place during composite formation was investigated. A stabilization of Ag nanoparticles in mixed colloids due to their interaction with soluble silicon oxide compounds was found. It was also revealed that the contact between silver and Si/SiO2 particles resulted in the decrease of the temperature at which the formation of additional oxygen-deficient centres occurs in the silica structure. New types of defects, namely 3-membered cycles and non-bridging oxygen groups, appeared as a result of Ag and Si/SiO2 surface interaction at 700 °C. Thus, silver nanoparticles facilitated the formation of defects in the structure of SiO2.