Theoretical Study On Oxygen Reduction Reaction Of Two-Dimensional Materials And Electron,Magnetic And Chemical Activity After Doping

A unique two-dimensional material,graphene,was discovered in 2004 by two scientists,Andrew Gem and Konstantin Novo,of the University of Manchester.Graphene has a special monoatomic layer structure and good electronic properties.Its structure is mainly composed of C atoms in a sp² hybrid manner to form a special honeycomb structure,and its surface is prone to structural defects,so it has also become a research of a large number of researchers.Focus.With the development of graphene,scientists have begun to explore different two-dimensional materials,such as boron nitride nanosheets,MoS₂,etc.The perfection of computer technology has also made many problems that can no longer be solved by the laboratory,through the way of computational simulation.Explain the phenomenon of low-dimensional nanomaterials.In this paper,according to the basic theory and basic research methods such as density functional theory?DFT?,molecular orbital theory?MO?,density of states?DOS?analysis,using the Materials Studio 7.0?MS?program for non-metal doping and adsorbed two-dimensional materials were theoretically studied for their catalytic properties,electronic structures and geometric configurations.This article is mainly composed of four chapters.In the first chapter,we mainly introduce the development background and application prospects of quantum chemistry,and summarize the main work of the article.The second chapter mainly introduces the basic assumptions,reaction potential energy surface,density functional theory,transition state theory,and the basic knowledge and basic methods applied in the calculation process.In the third and fourth chapters,we have conducted a specific system exploration based on the above theory.In Chapter 3,using density functional theory?DFT?,we explored the possibility of using easily fabricated boron nitride?BN?nanosheets as ORR electrocatalysts.The results show that O₂ can be strongly chemisorbed on charged BN nanosheets,which is a necessary step to initiate the reaction sequence.The calculated activation energy and reaction energy of each ORR step indicate that the ORR can easily form two H₂O molecules by a direct four-electron route,wherein the rate determining step is OOH*+H⁺+e^-?2OH*,and these results indicate The negatively charged BN nanosheet is a promising metal-free ORR electrocatalyst with high efficiency.Chapter Four,through density functional theory?DFT?calculations,we systematically studied the electron and magnetic properties and chemical reactivity of several experimentally available doped MoS₂ nanosheets for non-metal atoms?B,C,N,O,and P?.Our results show that these non-metallic atoms can be strongly captured by the S vacancies of MoS₂ nanosheets,ensuring their high stability.Furthermore,these doped MoS₂ nanosheets exhibit a reduced band gap due to the introduction of impurity levels.In particular,due to non-metallic doping,the adsorption of gas molecules on the MoS₂ monolayer can be greatly enhanced,indicating that there is a great potential for developing gas sensors or catalysis.