Heterogeneous deposition of noble metals on semiconductor nanoparticles in organic or aqueous solvents

We describe a versatile approach for synthesizing heterogeneous semiconductor/noble metal nanostructures both in organic and in aqueous solvent at room temperature. The deposition is based on the preferential nucleation and growth of noble metals (Au, Ag) at a single nucleation site on semiconductor (PbS) nanocrystals. The synthesis of multifunctional heterogeneous nanostructures of PbS - Au and PbS Ag was demonstrated. The self-assembly of the heterogeneous structures into ordered arrays was observed by transmission electron microscopy (TEM), which may lead to semiconductor - metal nanostructures with potential for self-assembly, geometric complexity, and multifunctionality. Also, the successful deposition of Au on PbS in the aqueous phase may find use in biological applications.