Ultrasound-Assisted Synthesis of SnS Quantum Dots Using Acetone as Solvent.

A sonochemical synthesis of SnS quantum dots using acetone as a solvent is investigated. Two different tin sources (SnCl∙2HO or SnCl∙5HO) as well as two different sulfur sources (thioacetamide or NaSO) were applied. The sonication time was also varied between 60 and 120 min. Resulting products of syntheses were characterized with the following techniques: powder X-ray diffraction, electron microscopy (SEM and HR-TEM), Raman and FT-IR spectroscopies, the Tauc method, and X-ray photoelectron spectroscopy. Obtained SnS nanostructures were in the form of quantum dots in the case of synthesis lasting 60 min (size of crystallites in the range of 3.5-7 nm) and in the form of elongated nanorods of length ca. 25-30 nm and width of 5-6 nm in the case of synthesis lasting 120 min. XPS analyses revealed that the surface of the obtained products contained a significant amount of tin at the second oxidation state (i.e., SnS). The quantum dots produced in the synthesis lasting 60 min showed a value of energy bandgap of 2.7 eV indicating potential applications in photocatalysis.