The impact of nanoparticle (NP)-based technologies encompasses a broad range of application areas. Moreover, the adsorption of organic compounds (ligands) on metal-based NPs combines chemi-/physisorption phenomena where weak interactions play a vital role in describing the adsorption sites, interface, and orientation ligands, and adsorption energies. The formation of self-assembly monolayers (SAMs) by the functionalized ligands and the interfaces plays a pivotal role in most NP-based materials and devices' overall efficiency. To understand the properties of the interfaces, SAMs forming mechanism by the ligands is now a challenging research area and enigmatic. To understand the phenomenon of NPs (Gold) and ligands interface, we have carried out density-functional theory calculations using PBE generalized gradient approximation (GGA), different vdW density functionals like semi-local optB86b-vdW and nonlocal vdW-DF2, as well as strongly-constrained and appropriately normed (SCAN) meta-GGA functional. End-functionalized alkane thiols such as 11-mercapto-1-undecanoic acid (C11COOH) are considered as ligands to reveal the geometric and the electronic structure of the interface of Au(111)/C11COOH. We found that SCAN functional is accurate enough to approximate the experimental lattice constant and bulk physical properties of Au, with a better description of adsorption energies. We also used ab intio MD (AIMD) simulation to investigate the formation of SAM with the use of optB86b-vdW functionals and found that four different phases of SAMs formation with different stability. In the future, we will perform an AIMD simulation using SCAN functional to evaluate its performance and compare it with PBE.

Self-assembled monolayers of thiols on gold surface: non-local to semi-local van der Waals density functionals

ACS Spring Meeting 2021

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