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

An approach for synthesizing heterogeneous semiconductor/noble metal nanostructures both in organic and in aqueous solvent at room temperature was investigated. This method involves the synthesis of PbS nanoparticles in the organic phase and a series of phase-transfer processes nanoparticles and from water to toluene for noble metal precursors. PbS was selected as the target semiconductor because of its wide application in solar cell construction, and because it can easily be produced in controlled shapes and sizes. Mercaptopropionic acid and dimethylainopyridine were used to replace oleic acid from starting PbS nanoparticles to make them dispersible in water. No change in particle size and distribution of PbS nanoparticles was observed during this reaction process. The result also showed that only a single site on the PbS nanoparticle surface facilitated the nucleation of gold clusters.