CAREER: Multi-atomic Layered Electronic Metal-organic Materials

金属-有机杂化材料（mom），如配位配合物、配位聚合物（CP）和金属-有机框架（MOFs），具有巨大的结构多样性，因此在磁性、催化、传感、气体储存和分离以及生物医学应用方面得到了广泛的研究。理想情况下，将mom的合成可调性与电子特性（例如，导电mom，称为emom）相结合，将扩展传统无机电子材料的分子功能，为解决许多重要的电子/电化学设备（包括可穿戴设备、传感器、电催化剂和电化学储能）中的挑战提供新的机会。不幸的是，目前传统的mom本质上主要是绝缘体。在材料研究部固态与材料化学项目的支持下，冯大伟教授研究了基于二维（2D）多层原子结构（M-eMOMs）合成新型eMOMs的一般方法。本研究利用mom的结构多样性来释放其在先进电子和电化学器件中的全部潜力。PI和他的团队还与材料研究科学与工程中心（MRSEC）教育小组以及威斯康星大学麦迪逊分校的化学教育研究所（ICE）合作，组织了“在家制作mof”课后充实计划。通过综合教育计划，中学生将获得使用安全、日常可获得的材料合成mom的实践经验，以培养他们对STEM的兴趣，本科生和研究生将接受材料科学、化学和储能设备制造方面的跨学科培训。金属有机材料（mom）的成分多样性和合成可调性使它们在一系列应用中具有巨大的潜力，在这些应用中，精确调整结构和功能起着至关重要的作用。将电子特性（例如，电子导电性）集成到mof中是特别有趣的，因为它在电子特性的基础上增加了多种功能，这极大地丰富了当前电子材料的类别及其应用范围。然而，大多数mom都是绝缘体，只有少数例外，其中大多数采用单原子层状p-d π共轭二维结构。NSF CAREER项目通过组装具有p-d σ共轭的多原子层状二维结构，即M-eMOMs，开发了新型的电子导电mom，称为eMOMs。系统地对金属和有机配体进行微调谐以操纵M-eMOMs的电子特性和功能。采用动力学控制合成方法来实现高结晶M-eMOM产品，以精确测量其固有特性。这允许阐明金属和有机建筑单元之间相互作用的基本方面以及随后对体电子特性的影响。反过来，这项研究有望在各个领域得到应用，包括电催化和柔性电子设备。这项工作不仅提供了一个将金属与有机建筑单元结合的新平台，而且还引入了具有极大扩展分子工程潜力的新的2D候选材料。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARYMetal-organic hybrid materials (MOMs), such as coordination complexes, coordination polymers (CP), and metal-organic frameworks (MOFs), possess vast structural diversity and thus have been extensively investigated for magnetism, catalysis, sensing, gas storage and separation, and biomedical applications. Ideally, embedding the synthetic tunability of MOMs with the electronic properties (e.g., electrically conductive MOMs, called eMOMs) would expand the molecular functionality of conventional inorganic electronic materials, offering new opportunities to address challenges in many vital electronic/electrochemical devices, including wearable devices, sensors, electrocatalysts, and electrochemical energy storage. Unfortunately, to-date conventional MOMs are primarily insulators by nature. With this CAREER project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, Prof. Dawei Feng studies a general approach to synthesize new types of eMOMs based on two dimensional (2D) multiple layered atomic structures (M-eMOMs). This research utilizes the structural diversity of MOMs to unlock their full potential in advanced electronic and electrochemical devices. The PI and his team also partner with the Materials Research Science and Engineering Centers (MRSEC) education group and the Institute for Chemical Education (ICE) at University of Wisconsin-Madison to organize “Make MOFs at home” after school enrichment program. Through the integrated education plans, middle schoolers get hands-on experiences in synthesizing MOMs using safe, daily accessible materials to foster their interests in STEM, and undergraduate and graduate students receive interdisciplinary training in materials science, chemistry, and fabrication of energy storage devices. TECHNICAL SUMMARYThe compositional diversity and synthetic tunability of metal-organic materials (MOMs) give them great potential for a series of applications where precise tuning of structures and functionalities plays a vital role. Integration of electronic properties (e.g., electronic conductivity) into MOFs is of particular interest as it adds diverse functionalities on top of electronic properties, which greatly enriches the class of current electronic materials and the scope of their applications. However, the majority of MOMs are insulators with just a few exceptional examples, most of which adopt single atomic layered p-d π conjugated 2D structures. This NSF CAREER project develops new classes of electronically conducting MOMs, called eMOMs through assembling multi-atomic layered 2D structures with p-d σ conjugation, namely M-eMOMs. The metal species and organic ligands are systematically micro-tuned to manipulate the electronic characteristics and functionality of M-eMOMs. Kinetically controlled synthetic methodologies are adopted to achieve highly crystalline M-eMOM products for precise measurement of their intrinsic properties. This permits elucidation of fundamental aspects of interactions between the metal and organic building units and the subsequent impact on the bulk electronic properties. In turn, this research is poised to enable applications in various areas, including electrocatalysis and flexible electronic devices. This work not only provides a new platform to integrate metals with organic building units but also introduces new 2D material candidates with vastly expanded molecular engineering potential.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.