Synthesis of porous gold nanoparticle/MoS₂ nanocomposites based on redox reactions

We describe a facile method for preparing porous gold nanoparticle (Au-NP)/2H-form MoS₂ nanocomposites. The Au-NPs were formed by redox reactions between 2-dimensional MoS₂ nanoflakes with a 2H-form crystal structure and tetrachloroauric acid (HAuCl₄) in a water/ethanol mixture without adding any additional reducing agents. The structures of the Au-NP/MoS₂ nanocomposites were influenced by the molar ratio of the Au ion precursor and MoS₂, as well as the volume ratio of water and ethanol in the reaction mixture. Ethanol allowed the 2H-MoS₂ nanoflakes to maintain their original morphologies after the reaction to serve as the support framework, meanwhile the Au-NPs worked as a junction to construct a 3-dimensional (3D) nanoporous structure. The obtained porous nanocomposites worked as a material for surface enhanced Raman spectroscopy (SERS) due to the formation of many nanoholes with so-called "hot-spots" based on the assembled Au-NPs.