Nanoparticles and more specifically gold nanoparticles (AuNPs) attracted a great scientific and technological interest in the last few decades. Their popularity is attributed to their optical, electrical and magnetic properties which are unique and cannot be seen in the bulk. However, one of the main problems of AuNPs is their long-term stability. On the other hand, MoS2 nanoparticles (NPs) and single layers show great chemical stability, and exhibit excellent mechanical and tribological properties1 as well as being biologically benign2. Moreover, it is known that MoS2 can form conformal coating on topologically complex surfaces. Finally, due to the MoS2 NP unique optical properties, a hybrid AuNP core and MoS2 shell would be a unique, stable and interesting hybrid nanomaterial.
In this work we present a synthesis of AuNPs coated by MoS2 single-layer. i.e. a core-shell nanostructure (Au@MoS2). These hybrid nanoparticles can also be considered as fullerene-like MoS2 (IF-MoS2) NP with an AuNP core. The characterization of the NPs was carried out by transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), electron energy loss spectroscopy (EELS), scanning electron microscope (SEM), Raman spectroscopy and UV-Vis absorption. It was found that the AuNPs are 7-13 nm in diameter and are coated by a complete single-layer of MoS2 (or more) with an IF-MoS2 structure. The growth mechanism of the nanoparticles has been studied and is discussed hereby.
(1) Hu, J.; Zabinski, J. Tribology letters 2005, 18, 173.
(2) Wu, H.; Yang, R.; Song, B.; Han, Q.; Li, J.; Zhang, Y.; Fang, Y.; Tenne, R.; Wang, C. ACS nano 2011, 5, 1276.