Surface modification of metal nanoparticles is fundamentally important to modulate plasmonic behavior of metal-ligand hybrid system. These metal-organic hybrid interface systems are widely used in designing optoelectronic devices, photovoltaics etc. However, effects of structural parameters of surface bound organic adsorbates on the plasmonic properties of metal nanoparticles have yet to be completely understood. Here, we present our exciting work on functionalizing chemically synthesized gold triangular nanoprisms (Au TNPs) of ~ 42 nm of edge length with a series of organic ligands comprising of different surface binding head groups that can covalently attach to the gold nanostructures to demonstrate effect of surface binding head groups on the plasmonic property of the hybrid system. We have experimentally observed a LSPR peak red-shift of ~65 nm upon modifying surface binding atom from Sulfur (X= -S) to Selenium (X= -Se) starting from a cinnamic acid precursor (Ph-CH=CH-CO-X-). We performed density functional theory (DFT) calculations to understand the role of electronic interactions across the interface of the hybrid system. Density of states (DOS) calculation shows changes in the electronic structures near the Fermi level due to modification of surface binding head group further supporting the experimental observation. We have further explored different organometallic binding head groups such as N-heterocyclic carbenes (NHCs), N-heterocyclic boranes (NHBs) to understand fundamental LSPR properties of these systems depending upon the characteristic of electronic interactions at the surface. We expect that this fundamental study will unravel the fundamental mechanistic understanding of uniquely designed ligand-passivated plasmonic nanostructures expediting its potential applications in various fields such as energy conversion and storage, and sensing.

Understanding electronic interactions at the interface of metal-organic hybrid system through controlling surface binding head-group on gold nanostructures

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.