Investigation of Topological and Catalytic properties of Gold Iodide (AuI) monolayer: A DFT Study

Insulating bulk and conducting edge states makes two-dimensional (2D) Topological Insulators (TI) a candidate quantum material with varied applications. 2D binary monolayers composed of group-11 transition-metals and halides with puckered structure have been recently explored for their photocatalytic and quantum cutting properties. However, such binary systems have not yet been explored for their topological properties. In this study we explore the topological and catalytic properties of one such binary compound, Gold Iodide (AuI) which belongs to P63/mmc [194] space group governed by honeycomb lattice structure. The non-trivial TI nature exists in a narrow window of strain from −2% to 4%. Within this region; by employing strain engineering technique the band gap can be tuned to as high as 0.113 eV. The non-trivial character is further investigated by calculating the ℤ2 invariant, robust edge state spectra and slab band structures. We also compute the Gibbs free energy towards hydrogen evolution reaction (HER) to access the catalytic property of AuI. The Gibbs free energy was found to be −0.40 eV with Volmer-Heyrovsky as the prefered reaction mechanism. With this study we propose AuI monolayer as a candidate material for perspective applications in the field of nanoelectronics and catalysis.This article is protected by copyright. All rights reserved.