Nanostructured 2D-transition metal dichalcogenides

二维（2D）材料是那些像一张纸一样在一个平面上延伸的材料，但只有一个分子层厚。因此，基本上2D材料中的所有原子都位于表面并与其环境相互作用。这种形成反应性表面的能力使得2D材料对于促进化学反应很感兴趣，例如由电或光驱动的化学反应，这些过程分别被称为电或光。在完美的2D材料中，单分子层表面缺乏断裂键通常使它们具有相当的化学惰性。有用的化学官能团来自晶体缺陷，这些晶体缺陷具有挑战性，难以以可靠和受控的方式产生。在这个项目中，南佛罗里达大学的Matthias Batzill教授和他的团队正在设计具有原子级晶体修饰的2D材料。然后，研究人员将2D材料的结构和电子特性与其化学功能相关联。他们的研究可能会导致新的概念，使新的或改进的多组分2D材料的电催化。该项目的研究具有很强的跨学科性，教授学生化学概念，为他们在工业或学术界的工作做好准备。此外，该项目加强了国际合作，并鼓励学生通过促进与国外合作机构的学生交流来获得国际研究经验。 学生将与电子科技大学（UESTC）以及分别在意大利和法国的Elettra和Soleil同步加速器合作。 在化学部大分子，超分子和纳米化学（MSN）计划的资助下，研究了多组分和纳米结构的过渡金属二硫属化物（TMDC），以确定在这些材料中创建催化活性位点的基本原理。分子束外延（MBE）是用来合成具有明确定义的晶体修饰的模型系统。调节MBE中的生长条件使得能够控制边缘密度、组成和相边界以及本征和非本征缺陷。结构，缺陷和接口的特征在于与原子分辨率的扫描隧道显微镜和光谱。光电子能谱提供了额外的洞察电子状态和能带排列，促进电荷转移过程。这些结构和纳米结构的TMDC的电子性能相关的化学性质的结合真空表征的吸附和反应的探针分子，以及光催化和电催化的调查在现实的反应conditions.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

Two-dimensional (2D) materials are those that extend in one plane like a piece of paper, but are only a single molecular layer thick. Thus, essentially all atoms in a 2D material are located at the surface and interact with their environment. This ability to form reactive surfaces makes 2D materials interesting for promoting chemical reactions, such as those driven by electricity or light, processes known as electro- or photocatalysis, respectively. In perfect 2D materials, the lack of broken bonds at the surface of the single molecular layers often makes them quite chemically inert. Useful chemical functionalities arise from crystal imperfections that are challenging to create in a reliable and controlled manner. In this project, Professor Matthias Batzill and his group at the University of South Florida are designing 2D materials with atomic-scale crystal modifications. The researchers then correlate the structural and electronic properties of the 2D materials with their chemical functionalities. Their research may lead to novel concepts for making novel or improved multicomponent 2D materials for electrocatalysis. The research in this project is strongly interdisciplinary and teaches students chemistry concepts that prepare them for jobs in industry or academia. Moreover, this project strengthens international collaborations and encourages students to gain international research experience by fostering student exchanges with collaborating institutions abroad. Students will collaborate with the University of Electronic Science and Technology of China (UESTC) as well as at Elettra and Soleil synchrotrons in Italy and France, respectively. With funding from the Macromolecular, Supramolecular and Nanochemistry (MSN) Program of the Chemistry Division, multi-component and nanostructured transition metal dichalcogenides (TMDCs) are investigated to determine fundamental principles for the creation of catalytically active sites in these materials. Molecular beam epitaxy (MBE) is employed to synthesize model systems with well-defined crystal modifications. Regulating growth conditions in MBE enables control over edge density, composition, and phase boundaries, as well as intrinsic and extrinsic defects. The structure, defects, and interfaces are characterized with atomic resolution by scanning tunneling microscopy and spectroscopy. Photoemission gives additional insight into electronic states and band alignments that promote charge transfer processes. These structural and electronic properties of nanostructured TMDCs are correlated to chemical properties by a combination of vacuum characterization of adsorption and reaction of probe molecules, as well as photocatalytic and electrocatalytic investigations under realistic reaction conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.