First-Principles Study Of Transition Metals Embedded Monolayer MoS₂ For Small Molecules Adsorption

In recent years,MoS₂ has been a research frontier and hotspot in the field of gas sensor,catalysis and lithium ion battery due to its unique structure and excellent physicochemical properties.In order to further study the configurations,electronic structures of transition metals embedded monolayer MoS₂ and the adsorption performance of gas molecules,this paper has systematically investigated the configurations,electronic structures and adsorption performance of a series of transition metal?Fe,Co,Ni,Cu,Ag,Au,Rh,Pd,Pt and Ir?-embedded monolayer MoS₂ and the adsorption of gas molecules?CO,NO,O₂,NO₂ and NH₃?using the quantum mechanics method based on the first-principles and considering the dispersion force correction.The results of research show that after the transition metal?Fe,Co,Ni,Cu,Ag,Au,Rh,Pd,Pt and Ir?embedded monolayer Mo S₂,metal atoms are out of the MoS₂plane,forming long TM-Mo bonds.The strong interaction between the embedded atom and the surface indicates that the embedded surface is stable.The research results of the electronic structures show that after embedded monolayer MoS₂,Fe,Co,Ni,Cu and Ag lose some electrons?0.04-0.36 e?while Au,Rh,Pd,Pt and Ir atoms gain the electrons?0.11-0.34 e?.The state density analysis reveals that nd orbital impurity states of transition metals are introduced in the band gap of MoS₂ in different degrees.Furthermore,the embedded transition metal atoms effectively change the magnetic moment of the embedded surface,indicating that the embedded transition metal atoms can effectively regulate the electronic structure of MoS₂ surface.On the basis of the above work,we conduct a detailed study on the adsorption conditions for the respective adsorption of small molecules?CO,NO,O₂,NO₂ and NH₃?on TM-MoS₂?TM=Fe,Co,Ni,Cu,Ag,Au,Rh,Pd,Pt and Ir?.The results of research show that the adsorption energy for the adsorption of small gas molecules on transition metal embedded monolayer MoS₂ surface significantly increases?0.29-3.12eV?and the adsorption performance is obviously enhanced compared with pristine MoS₂ surface.The analysis results of electronic structures show that the strong interaction between nd orbitals of transition metal atoms and orbitals of gas molecules near Fermi level make the gas molecules activated,showing high adsorption performance and catalytic activity.The analysis results of Bader charge show that oxidizing gas molecules?NO₂,O₂?get more electrons?0.17-0.66 e?from transition metal embedded monolayer MoS₂ surface,and the reducing gas?NH₃?,as an electron donor,loses a small amount of electrons?0.11-0.22 e?after adsorption on the contrary.In addition,in a series of transition metal embedded systems,the adsorption of small molecules on Fe and Co embedded monolayer MoS₂ surfaces show the better thermostability,adsorption performance and chemical activity.