Preparation, characterization, and catalytic effect of CS2-stabilized silver nanoparticles in aqueous solution

CS2-stabilized silver nanoparticles of similar to6 nm in diameter are prepared in aqueous solution via chemical reduction of Ag+ ions by KBH4 in the presence of CS2. 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 UVisible 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 CS2 because of the strong affinity of S on the surface of Ag particles. The silver nanoparticles in the presence of CS2 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 CS2, which maybe a derivative (CS or CnSm of CS2). Again the catalytic reduction of a dye, 2,7-dichlorofluorescein (DCF), in the presence of CS2-stabilized silver particles is investigated.