Template-directed Synthesis of Ag2S-Fe2O3 Heterostructures

Controlled synthesis of optical-magnetic nanostructures has attracted more and more interest due to their simultaneous optical properties and magnetic manipulating. Ag₂S nanocrystals, with a low (~1.0 eV) band gap at room temperature, have become one of the most commonly studied semiconductor nanocrystals. Due to their excellent photoelectric and thermoelectric properties, Ag₂S nanocrystals have been widely used in photocatalysis, near-infrared fluorescence imaging, and photoconductive cells. In addition, Fe₂O₃ nanoparticles with or without interior voids have both magnetic and photocatalytic properties. Thus, the integration of Ag₂S and Fe₂O₃ nanoparticles may lead to further improvements of their optical performance. However, it still remains a difficult task to prepare these desired hybrids in a controllable fashion.

Herein, we demonstrated the synthesis of nanocomposites containing silver sulfide and iron oxide materials by the sulfidation of silver-iron oxide nanotemplates with elemental sulfur as sulfur resource. In the presence of oleylamine, the sulfidation of silver-iron oxide heteromers retained similar nanostructures as templates, indicating an in-situ sulfidation of silver. TEM images, UV-Vis absorption spectra and XRD patterns of as-prepared Ag-Fe₂O₃ and Ag₂S-Fe₂O₃ nanoparticles synthesized by sulfidation with elemental sulfur were shown in this paper. These investigations would help us to understand the sulfidation and growth process of nanomaterials and control their synthesis for a given application.