Zhu Hongxia, Zhao Xiaolei, Li Huanhuan, Zhao Ruiqi
Henan Key Laboratory of Materials on Deep-Earth Engineering, School of Materials Science and Engineering, Henan Polytechnic University, Henan 454003, China.
Phys Chem Chem Phys. 2020 Feb 21;22(7):4023-4031. doi: 10.1039/c9cp06425g. Epub 2020 Feb 5.
To improve the quality of chemical vapor deposition (CVD)-prepared hexagonal boron nitride (h-BN), it is essential to understand the growth mechanism, particularly to learn the structures as well as their stabilities and kinetic evolutions of the formed clusters in the initial growth stage. Herein, we performed systematic studies on the stabilities of various geometries of different-/identical-sized BN clusters on (111) surfaces of Ni and Cu by density functional theory simulations. The results show that the stable configurations of different-sized clusters are those containing the most normal hexagons composed with alternate B and N atoms. There exist ultra-stable magic clusters on the (111) surfaces of both the metals. On Ni(111), the geometries of the magic clusters are composed of hexagons arranged in the core-shell structure, while they contain tetragons on the Cu(111) surface. The ultra-high stabilities of the magic clusters can be attributed to the comprehensive effect from the core-shell structure, high symmetry, edged atoms, and adsorption sites. The stable geometries of different-sized clusters as well as magic clusters present the vital roles of metal substrates in CVD-synthesis of h-BN and provide instructive information in improving the quality of h-BN by selecting appropriate metal substrates.
为提高化学气相沉积（CVD）制备的六方氮化硼（h-BN）的质量，了解其生长机制至关重要，尤其是要了解初始生长阶段形成的团簇的结构及其稳定性和动力学演化。在此，我们通过密度泛函理论模拟，对不同尺寸/相同尺寸的BN团簇在Ni和Cu的（111）表面上各种几何结构的稳定性进行了系统研究。结果表明，不同尺寸团簇的稳定构型是那些包含由交替的B和N原子组成的最规则六边形的构型。在这两种金属的（111）表面上都存在超稳定的幻数团簇。在Ni（111）上，幻数团簇的几何结构由以核壳结构排列的六边形组成，而在Cu（111）表面上它们包含四边形。幻数团簇的超高稳定性可归因于核壳结构、高对称性、边缘原子和吸附位点的综合作用。不同尺寸团簇以及幻数团簇的稳定几何结构揭示了金属衬底在h-BN的CVD合成中的重要作用，并为通过选择合适的金属衬底提高h-BN质量提供了指导性信息。
