Ramos Manuel, López-Galán Oscar A, Polanco Javier, José-Yacamán Miguel
Departamento de Física y Matemáticas, Instituto de Ingeniería y Tecnología, Universidad Autónoma de Ciudad Juárez, Edificio G-301A, 450 Avenida del Charro, Ciudad Juárez 32310, Chihuahua, Mexico.
Applied Physics and Materials Science Department and Center for Material Interfaces Research and Applications (MIRA), Northern Arizona University, Flagstaff, AZ 86011, USA.
Materials (Basel). 2022 Sep 28;15(19):6732. doi: 10.3390/ma15196732.
We present a systematic density functional theory study to determine the electronic structure of bending 2H-MoS layers up to 75° using information from in-situ nanoindentation TEM observations. The results from HOMO/LUMO and density of states plots indicate a metallic transition from the typical semiconducting phase, near Fermi energy level () as a function of bending, which can mainly occur due to bending curvatures inducing a stretching and contracting of sulfur-sulfur chemical bonds located mostly over basal (001)-plane; furthermore, molybdenum ions play a major role in such transitions due to reallocation of their metallic -character orbitals and the creation of "", possibly having an overlap between Mo and Mo orbitals. This research on the metallic transition of 2H-MoS allows us to understand the high catalytic activity for MoS nanostructures as extensively reported in the literature.
我们开展了一项系统的密度泛函理论研究，利用原位纳米压痕透射电镜观察得到的信息，确定弯曲角度达75°的2H-MoS层的电子结构。最高已占分子轨道/最低未占分子轨道和态密度图的结果表明，在费米能级（）附近，随着弯曲角度的变化，典型的半导体相发生金属性转变，这主要是由于弯曲曲率导致位于基底（001）平面上的硫-硫化学键发生拉伸和收缩；此外，钼离子在这种转变中起主要作用，因为其金属性轨道重新分布并产生了“”，可能存在钼与钼轨道之间的重叠。这项关于2H-MoS金属性转变的研究使我们能够理解文献中广泛报道的MoS纳米结构的高催化活性。
