Effect of aqueous ammonia addition on the morphology and size of silver particles reduced by ascorbic acid

Controllable synthesis of uniform silver particles was investigated via rapid mixing of l-ascorbic acid aqueous solution and silver–amine complex aqueous solution in the presence of polyvinyl pyrrolidone (PVP) at room temperature. It is found that the addition of nitric acid and aqueous ammonia into the reaction solution has a crucial effect on the final morphology of the resulting products. Furthermore, the effect of aqueous ammonia addition on the morphology and size of silver particles was investigated in this study. Smooth silver particles with the diameters ranging from 0.2 μm up to 2 μm were obtained by varying the concentration of aqueous ammonia. The synthesis method was of excellent stability in the range of 20–40 °C, which can be considered as an effective method for large-scale preparation of mono-dispersive silver particles with a wide size range.