Using Cation-Exchanged Nanorod Templates To Direct the Regioselective Growth and Plasmonic Coupling of Gold Nanoparticles

Abstract

Plasmonic coupling of gold nanoparticles results in a red shift of the plasmon peak in the visible absorption spectrum, resulting in a color change that is sensitive to interparticle spacing. Here, we used multiple sequential partial cation exchange reactions to design heterostructured nanorod templates that define the regions onto which gold nanoparticles photodeposit. Starting with nanorods of copper sulfide (Cu 1.8 S), we synthesized ZnS−CdS, CdS−ZnS−CdS, and ZnS−CdS−ZnS nanorods. Illumination with a blue LED light initiated the photodeposition of Au nanoparticles selectively onto the CdS regions. Subsequent cation exchange reactions transformed the CdS regions to Cu 1.8 S and then to ZnS while also facilitating surface diffusion and migration of the photodeposited Au, which coalesced into single particles through a surface ripening process. This process produced nanorods that were fully ZnS but with Au nanoparticles anchored in distinct regions. The Au−ZnS−Au sample exhibited a red shift of the plasmon peak relative to Au−ZnS, due to plasmonic coupling of the Au particles on the ZnS nanorod support.

Disentangling Competitive and Synergistic Chemical Reactivities During the Seeded Growth of High-Entropy Alloys on High-Entropy Metal Sulfide Nanoparticles

“…Here, we seek to grow SnPdPtRhIr selectively on one metal sulfide when two are present. Partial cation exchange can be leveraged to regioselectively direct seeded growth. , However, given the compositional complexity of SnPdPtRhIr, its application here is, in principle, a challenging undertaking, since it is plausible that all five individual metals could have different seeded growth preferences and therefore disfavor nucleation and growth of the high-entropy alloy. We hypothesized that if we chose one metal sulfide that seeds the growth of a single domain of SnPdPtRhIr and another where growth of SnPdPtRhIr on preexisting seeds outcompetes the nucleation and growth of new seeds, we could favor seeded growth of SnPdPtRhIr on one metal sulfide and disfavor it on the other.…”

Synthesis Innovations and Applications of Dual Plasmonic Heteronanostructures: Fundamentals to Future Horizons

“…They observed that the coupled excitation of Au–GSH/Ag NP resulted in an enhanced plasmon response of the metal NPs, thus, providing a future niche for better understanding of such interactions to uncover major trends in plasmonic research. Recently, Milliron’s group demonstrated that surface functionalization of Sn-doped indium oxide NCs with dipolar ligands can tune their LSPR properties, while Schaak and co-workers report the LSPR coupling of Au NPs selectively grown over NR templates . These results have provided new research directions and laid out guidance for future efforts.…”

“…Recently, Schaak’s group reported the plasmonic coupling of Au NPs on the ZnS NR solid-state support. They first synthesized Cu 1.8 S and capitalizing the cation exchange reaction mechanism they transformed it to heterostructured ZnS–CdS, CdS–ZnS–CdS, and ZnS–CdS–ZnS NRs (schematic shown in Figure a) . When these nanosystems were irradiated with blue LED light in the presence of Au precursors, the Au NPs were selectively photodeposited onto the surface of the CdS NRs.…”

“…(b) Absorption spectra illustrating LSPR peak of ZnS (Au) NRs (red) and the Au–ZnS–Au NRs (blue), displaying a red-shift occurs due to coupling between two Au NPs that are attached to the ZnS NRs. Panels (a) and (b) are adapted with permission from ref . Copyright 2023 American Chemical Society.…”

Influence of Surface Chemistry on Metal Deposition Outcomes in Copper Selenide-Based Nanoheterostructure Synthesis

“…There is a large and growing interest in the creation of metal–semiconductor hybrid nanomaterials because of their unique properties and applications including in photocatalysis, − optoelectronics, , and biological imaging/diagnostics. − To efficiently match structure with function, there has been sustained interest in establishing synthetic methods for precise control of their morphology. − A particularly successful approach for tuning these heterostructures has been postsynthetic modification of starting nanoparticle (NP) substrates. − There are several advantages to postsynthetic modification strategies for tuning nanoheterostructure morphology including the improved ability to tailor interfaces within the structure such as interface size, composition, number, and/or extent (e.g., gradient). Strategies such as cation/anion exchange and galvanic replacement have led to remarkably complex structures, ,,,− with both established and still studied new physical and chemical behaviors of interest. − …”