Electrocatalytic Activity Of Nonmetallic Single Atom Doped Antimonene For Hydrogen Evolution

Hydrogen energy is regarded as one of the most valuable clean energy sources.Among the various processes for preparing hydrogen energy,electrocatalytic water splitting is considered to be a simple,easy-to-control,clean and environmentally friendly method.In order to quickly and efficiently produce hydrogen energy,it is particularly important to develop electrocatalysts with high activity,high stability,and low-cost.In this thesis,based on density functional theory,we firstly study the catalytic effect of group of V and group of VI single atoms(N、P、As、O、S、Se、and Te)on the hydrogen evolution reaction after anchored to the two-dimensionalβ-Sb surface vacancies.The calculation results show that whenβ-Sb surface is doped with group ofⅥelements,Se@Sb structure with doping molar concentration of 2.78%,O@Sb structure and S@Sb structure with doping molar concentration of 5.56%show HER electrocatalytic activity comparable to that of Pt(111)surface while maintaining stability.In addition,studies have shown that applying about 4%～5%x and y biaxial compressive stress to the Te@Sb structure can also realize the regulation of HER catalytic activity.The research content of this work not only designs the D@Sb doping structures which can effectively improve the electrocatalytic activity of HER,but also describes the reasons for the improved catalytic activity ofβ-Sb surface atoms from the physical perspectives of Bader charge,the projected density of states(PDOS),and the crystal orbital Hamilton population(COHP).In the process of researching for the mechanism,a new physical quantity,the number of electrons at Fermi level,describes the catalytic activity of HER electrocatalyst,is revealed.Overall,the research work will provide help for the application ofβ-Sb materials in the future.The content of this thesis is arranged as:Chapter One:Introduction.Firstly,the importance of hydrogen energy to social development in recent years is briefly summarized.Secondly,the basic principle and mechanism of electrocatalytic cracking of water to produce hydrogen energy are described.Chemical reactions require catalysts to speed up the reaction rate and improve the utilization of reactants,so the electrocatalysts of HER are mainly described in the last part of this chapter.Chapter Two:Theoretical Methods.In the first part,the basic theoretical knowledge and development of the first principles of computational physics are briefly introduced;The second part describes some theoretical tools needed in the related work of computational electrocatalysis.Finally,the softwares used in this work are summarized at the end of this chapter.Chapter Three:Research Content.First of all,a brief introduction to the geometric and electronic structure ofβ-Sb,a typical honeycomb two-dimensional material,followed by a discussion of the specific work content of this thesis,is given.Then,the contents of this research work are described in detail.The results show that when D=O,S,Se,and Te,the Sb atoms in the doped structure D@Sb can show good HER catalytic activity.In addition,it is concluded that the main reason for the change of catalytic activity is that the bring in of single atom rearranges the electrons on the surrounding Sb atoms,especially the creating of local holes in the s-p_z orbit of Sb atoms greatly weakens the Coulomb repulsion to H atoms.Chapter Four:Summary and Outlook.Summarize the important conclusions based the work onβ-Sb materials,and propose the potential value of this research work.