Synthetic Routes to Hybrid Nanoparticles of Gold and Copper Sulfides

Abstract

The rational design of hybrid nanoparticles is a powerful tool in harnessing nanoscale properties of several different materials in a single whole. The first portion of this work describes the synthesis of dual-plasmonic hybrid gold-copper sulfide nanoparticles for application in the enhancement of second harmonic generation of light. Established synthetic methods were applied to create hybrid nanoparticle systems that contained two separate localized surface plasmon resonances. The second portion of this work describes the synthesis of gold sulfide nanoparticles via a cation exchange procedure with copper sulfide nanoplatelets. The growing significance of the copper sulfides as a nontoxic alternative to commercially significant quantum dot materials such as PbS and CdS has led to a proliferation of work studying these materials. However, Au2S, a material with potential for many of the same applications as Cu2S, remains relatively ignored. The inherent difficulty of direct synthesis of gold (I) sulfide in the nanocrystalline form as well as the metastable nature of the material once synthesized are significant obstacles to the study of Au2S. We report an indirect synthesis of Au2S nanocrystals and Au2S—Cu2-xS hybrid nanoparticles via cation exchange, and the insights into this material transformation gained in this study.