Precipitation of Nanocrystalline Silver Sulfide from Aqueous Solutions Containing a Stabilizer

Abstract

Chemical precipitation from aqueous solutions of silver nitrate and sodium sulfide in the presence of sodium citrate as a stabilizer was used to synthesize powders and colloidal solutions of silver sulfide Ag₂S. The methods of X-ray diffraction, dynamic light scattering, and low-temperature adsorption of nitrogen were used to estimate sizes of silver sulfide particles in the precipitated powders and colloidal solutions. Changing the ratio between the reagent concentrations in reaction mixtures made it possible to obtain Ag_2S nanopowders with average particle sizes within the range from ∼1000 to 40–50 nm. The size of Ag_2S nanoparticles in the colloidal solutions obtained is 15–20 nm. The relationship between the particle size of silver sulfide and the supersaturation of solutions used for synthesis was considered.