Synthesis of Ag2S-ZnS Composite Powders

Abstract

On the synthesis of Ag2S-ZnS composite particles from the mixture of silver nitrate and zinc nitrate solution by homogeneous precipitation method using thioacetamide at 70°C, the effect of Ag⁺ concentration on the morphology of products was investigated.
The precipitates were spherical composite particles with narrow size distribution when Ag⁺ concentrations ≤4×10^-4 mol dm^-3. At Ag⁺ concentrations ≥4×10^-3 mol dm^-3, Ag₂S-ZnS composite particles became aggregated ones. The formation of spherical Ag₂S-ZnS composite particles occurred by the deposition of ZnS at the initial stage on the surface of Ag₂Snuclei which were formed by reaction between Ag⁺ ion and thioacetamide.