Au-Cu2S heterodimer formation via oxidization of AuCu alloy nanoparticles and in situ formed copper thiolate

The synthesis of hybrid nanostructures has been of great interest to many material scientists, yet simple and facile routes to prepare these structures remain a difficult task with many reaction variables to tune. Herein, we report the synthesis of Au-Cu2S heterodimers from AuCu alloy nanoparticles by simply adding 1-dodecanethiol. Detailed characterization of this structural transformation process revealed that the crucial step of this synthetic approach was the alloy oxidization and subsequent formation of intermediate copper thiolate. Roles of surfactants and sulfur source have also been investigated. These observations provide critical insight into the understanding of the pathways of structure transitions from AuCu alloy to Au-Cu2S heterodimer nanoparticles, and will open up new ways of synthesizing heterodimer nanoparticles from metallic alloys.