Synthesis of worm-like Ag2S nanocrystals in W/O reverse microemulsion

High-aspect-ratio of worm-like Ag2S nanocrystal with length up to several micrometers and a diameter of 25–50 nm has been successfully prepared by a Triton X-100/cyclohexane/hexanol/water W/O reverse microemulsion in the presence of TAA (Thioacetamide) as a sulfur source and EDTA (ethylene diamine tetraacetic acid) as a chelating ligand. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and UV–vis diffuse reflectance absorption spectra. The results indicate that the morphology and size of Ag2S nanocrystal can be readily controlled by modulating the mole ratio of Ag+ to EDTA, the molar ratio of water to surfactant (ω0), and the aging time.