Water Splitting Mechanism on 2D Catalytic Materials : DFT based Theoretical Investigations

Abstract: In this thesis, we have envisaged systematic investigation to predict the water splitting mechanism on ultra-thin two-dimensional (2D) materials using cutting edge computation. Three different families of materials are considered as the case studies - i.MX2 (where M= W and Pt) based transition metal dichalcogenides, ii. lightest 2D material as Boron monolayer and iii. Mg3N2 monolayer. The catalytic reaction mechanism of water dissociation consists of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), both of which are required to be investigated thoroughly in order to perceive the complete picture of water splitting. This is because of the fact that the fundamental understanding of how and why the improved solar hydrogenproduction properties could be developed for such 2D materials is also of great technological importance. We have performed rigorous electronic structure calculations based on density functional theory (DFT) to find the optimum catalytic activity of the considered monolayer nanostructures. Hydrogen and oxygen evolution reaction activity are determined from the surface-adsorbate interaction based on the adsorption energy of the major intermediates of HER and OER mechanism. Our DFT based investigations will be the intuitive way to theoretically rationalize HER and OER activity for a series of functionalized different two-dimensional systems and can guide the actual experiment in the laboratory with a preconceived framework.