Formation of Metal Selenide and Metal-Selenium Nanoparticles using Distinct Reactivity between Selenium and Noble Metals.

Small Se nanoparticles with a diameter of ≈20 nm were generated by the reduction of selenium chloride with NaBH4 at −10 °C. The reaction with Ag at 60 °C yielded stable Ag2Se nanoparticles, which subsequently were transformed into M–Se nanoparticles (M=Cd, Zn, Pb) through cation exchange reactions with corresponding ions. The reaction with Pt formed Pt layers that were evenly coated on the surface of the Se nanoparticles, and the dissolution of the Se cores with hydrazine generated uniform Pt hollow nanoparticles. The reaction with Au generated tiny Au clusters on the Se surface, and eventually formed acorn-shaped Au–Se nanoparticles through heat treatment. These results indicate that small Se nanoparticles with diameters of ≈20 nm can be used as a versatile platform for the synthesis of metal selenide and metal–selenium hybrid nanoparticles with complex structures.