Unraveling the electrochemical mysteries of 2D monolayer transition metal dichalcogenides for oxygen reduction and hydrogen evolution reactions

Abstract

The first chapter of this thesis work extensively examines the crucial domains of electrocatalysis, with a particular emphasis on investigating the HER and ORR occurring on surfaces of 2D TMDs. The present study explores the structural and electronic properties of these 2D TMDs and their electrocatalytic activity towards ORR and HER. The second chapter of this thesis outlines the methodology employed in the present study. In this chapter, a comprehensive exploration is provided on computational science, methodology, theory, and the intersection of computational materials science with chemistry. The third chapter of this thesis encompasses the design of a 2D monolayer of MoSe2 doped with Pt (referred to as Pt-MoSe2). We delve into the examination of its electronic characteristics, specifically focusing on the energy band structure and total density of states. Additionally, we investigate the electrocatalytic capabilities of the Pt-MoSe2 2D monolayer in the context of the oxygen reduction reaction (ORR), including a comprehensive analysis of both the full ORR pathways and the reaction mechanism. These investigations involve the c􀁒􀁐􀁓􀁘􀁗a􀁗i􀁒􀁑 􀁒f 􀁗he 􀁕e􀁏a􀁗i􀁙e Gibb􀁖 f􀁕ee e􀁑e􀁕g􀁜 (􀇻G) 􀁘􀁖i􀁑g 􀁗he 􀁖a􀁐e de􀁑􀁖i􀁗􀁜 functional theory (DFT) method. The fourth chapter of this thesis is the progression of the third one which includes the designing of a molecular cluster model system of the 2D monolayer Pt-MoSe2 crystal structure. The molecular cluster model (Pt1-Mo9Se21) system of the 2D monolayer Pt-MoSe2 TMD material was used to explore both the ORR and HER activity by exploring all the steps of all the reactions, including TS calculations and thermochemistry calculations. In the fifth chapter of this thesis, a 2D monolayer Janus TMD, MoSSe, was studied. We investigated the electronic properties and designed a molecular cluster model to study the whole HER mechanism.