Formation of Ag2S nanowires and Ag2S/CdS heterostructures via simple solvothermal route

In our present work, Ag2S nanowires and Ag2S/CdS heterostructures have been successfully prepared in anhydrous ethanol through a simple solvothermal route. From the transmission electron microscopy (TEM) analysis, it is found that the factors influenced the final product are the concentration of Ag+, reaction temperature, reaction time, and solvent. Ag2S nanowires are formed by complete Ag+ cation exchange. Because of the selectivity for partial cation exchange, the reaction starts preferentially at the ends of the CdS nanowires to produce novel Ag2S/CdS heterostructures. In addition, as the two end facets of wurtzite CdS nanowires are crystallographically nonequivalent, the produced Ag2S/CdS heterostructures are asymmetric.

Graphical abstractAg2S nanowires and Ag2S/CdS heterostructures have been successfully prepared in anhydrous ethanol through a simple solvothermal route. To our knowledge, there is no report of synthesis of silver sulfide nanowires in anhydrous ethanol solution using CdS nanowires as sacrificial templating until now. Furthermore, the novel Ag2S/CdS heterostructures have been successfully synthesized under suitable condition which is obviously different from previous reports. The selectivity for cation exchange reaction is the novel discovery, which starts preferentially at the ends of the CdS nanowires to form novel Ag2S/CdS binary heterostructures. This is the first report in the paper for our knowledge.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ag2S nanowires have been successfully prepared in anhydrous ethanol through a sacrificial templating route. ► The novel Ag2S/CdS heterostructures have been successfully synthesized under the suitable reaction condition. ► The growth of Ag2S nanoparticles at the end of CdS nanowires is attributed to the partial of Ag+ preferential exchange by controlling the experimental conditions.