Electronic structures and properties of 2D layered structure materials and their applications

Abstract

Two dimensional (2D) materials have distinctive features such as ultrathin atomic thickness and large surface to volume ratio have won great interest in their fundamental studies. The exploration of single layer graphene in 2004 showed that it is possible to create single atom thin materials and that these layered materials can have fundamentally different properties from their parent bulk materials. 2D transition metal dichalcogenides (TMDs) have emerged as a superlative class of materials for several applications in electronic devices, energy storage devices, gas sensing etc., and they have garnered a tremendous attention in intensive research. Here, we have computationally developed 2D layered structure Mn-MoS2 material for the investigation of catalytic performance in hydrogen evolution reaction (HER). Stable S terminated edges of the pristine 2D MoS2 shows low catalytic activity due to its inert basal plane. To activate the inert basal plane of the pristine 2D TMDs, it is needed to create some defects or doping of some heteroatoms in the pristine TMDs. Phase engineering techniques have been used to activate the basal plane of the 2D TMDs. So to exploit these edges for improved performance we doped Mn atoms in the MoS2. Using trailblazing and state of the art first principles-based density functional theory (DFT), we performed methodical and rigorous inspection of electronic structures and properties of the 2D monolayer Mn doped MoS2 which might be a promising alternative to noble metal-based catalysts for HER. Periodic 2D slab of the Mn-MoS2 was created to study the electronic properties and the reaction pathway on the surface of the material has been explored by using Mn1Mo9S21 molecular cluster model system. The reaction mechanism has been studied in both the gas and solvent phases. Our study reveals that 2D monolayer Mn-MoS2 based catalyst follows Volmer-Heyrovsky reaction with very low energy barriers during the HER mechanism. This study is focused on designing low cost and efficient electrocatalysts for HER by using earth abundant TMDs and lowering the activation barriers by scrutinizing the kinetics of the reaction for reactivity.