Preparation, Characterization, and Catalytic Effect of CS2-Stabilized Silver Nanoparticles in Aqueous Solution

CS 2 -stabilized silver nanoparticles of ∼6 nm in diameter are prepared in aqueous solution via chemical reduction of Ag + ions by KBH 4 in the presence of CS 2 . The product is proven to be Ag by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electron diffraction (ED) patterns. In the UV−visible spectra, an intense surface plasmon is built up at 350−500 nm, and it is centered at 395 nm after the reduction of Ag + ions. This can be assigned to a reaction product of Ag with CS 2 because of the strong affinity of S on the surface of Ag particles. The silver nanoparticles in the presence of CS 2 remain stable for months at room temperature. It is also found that the absorption band in the range 300−350 nm increases, is centered at 325 nm, and depends on the concentration of CS 2, which maybe a derivative (CS or C n S m of CS 2 ). Again the catalytic reduction of a dye, 2,7-dichlorofluorescein (DCF), in the presence of CS 2 -stabilized silver particles is investigated.