Preparation of silver nanoparticles in aqueous solutions in the presence of carbonate ions as stabilizers

摘要

Silver nanoparticles are prepared by reducing Ag~+ ions with sodium borohydride in aqueous solutions containing carbonate ions (5 × 10~(-5)-1 × 10~(-2) mol l~(-1)). It is established that carbonate ions represent an efficient stabilizer that provides nanoparticles with electrostatic protection via the formation of an electrical double layer. The maximum stability of a silver dispersion is observed at a carbonate ion concentration of 1 × 10~(-3) mol l~(-1). The average size of silver nanoparticles is 10.0 ± 2.5 nm. The formation kinetics of silver nanoparticles is described by an equation for a first-order reaction with a rate constant of 2.3 × 10~(-3) s~(-1) (±20%).