Size-Controlled and Size-Designed Synthesis of Nano/Submicrometer Ag Particles

A series of nano/submicrometer Ag particles with uniform size-distribution are prepared using ascorbic acid to reduce AgCl in aqueous solution and at ambient conditions. NaOH is used to adjust the redox potential of ascorbic acid, and polyvinylpyrrolidone (PVP) is used to balance the relative rates at which various crystallographic planes of Ag grow. Under the reaction conditions, the nucleation and growth steps are separated, thus controlling the anisotropic growth of the Ag crystals. The products are studied using transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and UV-vis spectrophotometry. On this basis, an equation for the relationship between the synthesis conditions and the size of the product was established, which can be applied to produce quantitatively size-controlled and size-designed Ag particles. Scale-up of the synthetic procedure is also conducted to test the prospect of large-scale synthesis of Ag particles for practical industrial applications.