A Synthetic Exploration of Metal–Semiconductor Hybrid Particles of CuInS₂

The ternary copper chalcogenide semiconductor nanoparticles have gained much attention as their optical properties make them ideal candidates for many applications ranging from photovoltaics to bioimaging. While their synthesis is well documented, there have been few reports on the synthesis of ternary copper chalcogenide–metal hybrid nanoparticles, which can further expand the list of potential applications through synergistic properties. To this end, Pt–CuInS 2 hybrids have been synthesized by a two-step approach in high boiling organic solvents. The hybrid nanostructures were characterized employing transmission electron microscopy, X-ray diffraction, UV–Vis spectroscopy, and energy-dispersive X-ray spectroscopy mapping. We find that during hybrid nanoparticle synthesis under conditions modified from typical Pt nanoparticle reaction schemes, a near-complete shell of Pt forms on the semiconductor nanoparticles. Careful control of the reactivity of the Pt precursor, through choice of organic reducing agent and Pt coordinating ligands, was successfully used to obtain controlled and isolated domains on the semiconductor nanoparticles. This strategy was further extended for the synthesis of Pd–CuInS 2 hybrids.