Catalysis of the Reduction of Silver Ions by Ag2S Nanoparticles

Silver sulfide nanoparticles were found to catalyze the reduction of Ag⁺ ions by sodium sulfite and hydroquinone. The change in the absorption spectrum of the reaction mixtures was studied. New bands were found to arise at 403, 415, and 426 nm depending on the reaction conditions. These bands were identified as plasmon bands of metallic silver nanoparticles. The kinetics of this process was determined under various conditions and Ag₂S nanoparticles were found to be a highly active catalyst.