合金及衬底近表面合金方法调控二维材料性能的理论研究

Exploring new structures and novel properties are the main research tasks in the field of two-dimensional (2D) materials. The extraordinarily extensive experimental investigations call for comprehensive studies of the new structure designing and the mechanism of property tuning, and even more require developing new idea to explore the properties and structures of 2D materials. Aiming to study the fundamentally important topics of the “new structures” and “novel properties”, we would carry out detailed first-principles calculations, in combination with the phonon spectrum analysis, molecular dynamics simulation, non-equilibrium Green’s function, revised nudged elastic band method, etc. to focus on the following studies: (a) Alloying the 2D materials, we would carefully analyze the stabilities from the sides of the thermodynamics and kinetics, and even more discuss the possibilities for their fabrication on experiment. Then, detailed studies on the physical and chemical properties would be performed for the stable alloy structures; (b) Taking into account the dispersive force, we would carefully investigate the interface structure and its effects on the properties of the 2D materials in heterostructures and those supporting on substrate; (c) By using the method of the substrate near-surface alloying, we would study the property modification of the 2D materials supported on the substrate and discuss the physical origin, whose dependence on the near-surface alloy structure and density would be also examined; (d) Finally, for our studied 2D alloy structures and the modified 2D materials by the near-surface alloy supporting, we would also calculate their transport properties and evaluate their usage for the nano-catalyst as supporting gold clusters etc. and the energy storage as storing lithium ions etc. In summary, on the basis of the analysis of structural and electronic properties, we would study in detail the new structures and novel properties of 2D materials on the atomic level by using the “alloying method” and “substrate near-surface alloying method”. Also, for some 2D alloy materials, the relationship between the “3p rule” and the property modulation would be carefully examined in this prospoal. These studies can provide theoretical knowledge to aid the experimental investigations of 2D materials. We believe that our results could benefit the new material design and to some sense provide predictions or guide further studies on experiment.

新结构和新性能探索是二维材料领域的重要研究方向,广泛的实验研究对结构设计和性能改善机理及新方案探索提出了迫切的理论研究要求。围绕“新结构”和“新性能”基础研究课题，我们基于第一性原理计算，结合声子谱分析、分子动力学模拟、非平衡格林函数和改进的Nudged Elastic Band等方法研究：①二维材料合金结构，分析稳定性及制备可行性，并研究其物理和化学性质；②异质结及衬底支撑二维材料，研究弱相互作用，分析界面结构及其对材料性质的影响；③衬底近表面合金，研究合金结构和浓度对二维材料的性质改善及机理；④对二维合金结构及近表面合金支撑二维结构，探讨其输运性质、担载金团簇等纳米催化应用、锂离子存储等储能应用。总之，以几何和电子结构研究为基础，以“合金方案”和“近表面合金”为创新，以探讨“3p规律”对相关合金结构的性质影响为特色，在原子层次上研究二维材料新结构和新性能，为实验研究提供理论成果借鉴。

自石墨烯在实验上成功制备以来，二维材料结构及性质探索获得了突飞猛进的研究进展，在项目研究中，我们主要采用第一性原理方法、遗传算法、动力学蒙特卡洛方法开展了：对新型二维材料结构进行了设计探索，对孤立的B-N、Al-N、B-过渡金属合金二维结构进行了研究，为这些结构的实验合成及相应的应用研究提供了理论成果借鉴；探索新型衬底支撑载体材料以降低二维材料制备和未来的应用成本，开展了Cu、Ag、Au、Pt、Al等金属(111)密堆面支撑锗烯、硅烯的生长模式，并探讨了表面合金修饰界面效应对生长模式的影响，另外还研究了Al(111)支撑的锗烯合金化过程研究，提出了最佳合金比例和对应的合金二维结构；利用多孔二维材料分散锚定贵金属团簇形成复合催化结构，研究中我们探索了COF-8和Penta-Graphene多孔材料支撑Pt团簇等的氢溢流机制，以及我们提出的Al(111)支撑多孔硅烯锚定Au团簇的CO氧化性质。通过项目研究，在原子层次上采用合金方案设计了一些新型二维结构、初步探索了界面效应对对支撑二维材料生长模式的影响和合金化结构设计、进行了一些多孔材料分散锚定贵金属团簇的应用性质探索，为实验和应用研究提供了理论成果借鉴，有利于新型高性能纳米材料设计研发。