金属表面原子台阶边缘合金的形成机制及其应用的理论研究

Metals are used in almost every aspects of our daily life. Their structural stability critically determines the live time of the systems and devices that are built upon metals and is extremely important especially for microelectronic devices. In addition, metals have already been widely used as a class of crucial catalysts in many industrial chemical reactions. This proposal aims to investigate how to enhance the structural stability of metal surfaces and optimize their catalytic performance by controlling the atomic structures of surface steps, based on our proposed new concept of "step alloy". We will systematically study the general rules of step alloy formation and their microscopic mechanisms using first-principles calculations, and use this new concept to search for ways of enhancing the stability of metals surface structures and tuning catalytic activity. This research will provide new strategies and pay new ways to tackle some critical issues in the fields of microelectronics, energy and environment.

金属材料普遍应用于日常生活的方方面面。其结构的稳定性直接决定着所组成的系统和器件的寿命，特别是对于精细的微电子器件来说极为重要。此外，在很多工业化学合成中，金属作为一类重要的催化剂也被广泛使用。此项研究拟在探索如何从原子尺度上通过对原子台阶处的结构修饰来增强金属表面的稳定性以及改善金属表面的化学催化活性。研究将围绕我们这里提出的"台阶合金"的新概念，以第一性原理计算为基础，系统地研究在金属表面上形成"台阶合金"的一般性规律及微观机理，并提出利用"台阶合金"这一新的途径来增强金属表面结构稳定性以及调控表面催化活性的设想。这将为解决微电子、能源和环境等领域的一些关键问题提供新的思路和途径。

该项目的研究围绕低维材料体系和表面纳米结构体系，主要研究成果包括：理论预言了首类同时具有面内和面外极化的稳定单层室温二维铁电材料；理论设计了具有鲁棒的双极磁性半导体石墨烯纳米通道结构；理论发现过渡金属二硫族化合物锯齿型边缘具有普适的自钝化重构机制及可能的边缘磁性；发现具有高效的二氧化碳转化甲醇的光催化活性二维BiVO4片层；理论提出通过石墨烯覆盖下镍表面实现高效产氢的受限催化机制；理论研究单层MoS2、蓝磷、有序氮掺杂石墨烯在衬底表面实现可控生长及其微观机理等。在该项目的资助下发表了包括Nature Communications、Physical Review Letters、Journal of the American Chemical Society、Nano Letters等在内的SCI论文16篇。