In situ synthesis of Ag–Cu bimetallic nanoparticles in silicate glass by a two-step ion-exchange route

Ag–Cu bimetallic nanoparticle/silicate glass composites were fabricated by means of a two-step ion-exchange and subsequently thermal treatment. Optical absorption spectroscopy and transmission electron microscopy (TEM) were used to study the influence of preparation conditions on the formation of Ag–Cu bimetallic nanoparticles in silicate glass. The results show that the volume fraction of copper nanoparticles increases with ion-exchange duration when keeping the same annealing temperature and duration in hydrogen atmosphere during the first stage of Cu doped glass. The Cu doped glass is beneficial to the formation of Ag nanoparticles during subsequent Ag+ for Na+ ion exchange. Extending Cu+ for Na+ ion exchange duration makes against the introduction of Ag ions into the Cu doped glass and the formation of Ag nanoparticles in the glass matrix. A few Cu2O nanoparticles were found in the glass matrix due to the oxidization of small Cu nanoparticles.