Towards supramolecular chemistry with inorganic 2D nanomaterial building blocks

自从突破性的发现，即石墨中的各个层可以稳定地分离出来，以产生原子薄的石墨烯纳米片以来，层状晶体受到了极大的关注。除了石墨，各种无机材料，如过渡金属二卤化物或III-VI半导体，都以层状形式广泛存在。作为一个过程，对单个纳米薄片的分层已经对材料科学和技术产生了革命性的影响，因为它打开了在二维(2D)剥离形式中发现的令人兴奋的性质，而不一定在它们的块状对应形式中看到。此外，剥离会产生高纵横比和表面积的材料。近年来，在从根本上研究一些2D材料的物理性质方面取得了重大进展。此外，还证明了它们可以在液体中剥离，从而可以从溶液中进行加工，这有利于将这些材料用作构建块，在从电子到储能或电催化的广泛潜在应用中。然而，到目前为止，对2D材料的化学研究还很少。特别是，广泛缺乏用于修饰光学、电子和表面性质的湿化学官能化序列。为了充分开发它们的潜力，有必要对它们的性质进行微调。在这个方案中，将在研究液体剥离的无机2D材料与广泛的有机分子和聚合物的非共价相互作用的基础上，探索一种多功能和高通量的功能化。纳米材料的光学指纹对其化学环境高度敏感，将用于跟踪掺杂或光致电荷转移等相互作用。在这种高通量筛选的基础上，将确定适合于阴离子、阳离子或中性官能团官能化的锚基。这将提供一系列具有定制性能的2D材料，这些材料可以通过旋转涂层、滴注或印刷等现有技术从液体中加工出来。反过来，这将允许使用超分子化学来制造多组分无机/有机杂化系统。这类体系对基础研究和各种应用都很有兴趣，因为可以利用不同类别的纳米材料之间的协同效应。

Since the ground-breaking discovery that individual layers in graphite can be stably isolated to yield atomically thin graphene nanosheets, layered crystals have received enormous attention. In addition to graphite, a broad range of inorganic materials such as transition metal dichalcogenides or III-VI semiconductors are widely abundant in their layered form. As a process, delamination to individual nanosheets has had a transformative effect on materials science and technology by opening up exciting properties found in the two-dimensional (2D) exfoliated forms, not necessarily seen in their bulk counterparts. In addition, exfoliation creates materials with high aspect ratio and surface area. Recent years have seen significant progress to fundamentally study physical properties of a number of 2D materials. In addition, it was demonstrated that they can be exfoliated in liquids giving access to processing from solution which is beneficial for using these materials as building blocks in a broad range of potential applications from electronics to energy storage or electrocatalysis. However, up until now, the chemistry of the 2D materials is only little explored. In particular, wet chemical functionalization sequences to modify optical, electronic and surface properties are widely lacking. To fully exploit their potential, it will be necessary to fine-tune their properties.Within this proposal, a versatile and high throughput functionalization will be explored based on studying the noncovalent interaction of liquid exfoliated inorganic 2D materials with a broad range of organic molecules and polymers. The optical fingerprints of the nanomaterials which are highly sensitive to their chemical surrounding will be used to track interactions such as doping or photoinduced charge transfer. Based on this high throughput screening, suitable anchor groups for the functionalization with anionic, cationic or neutral functional moieties will be identified. This will give access to a broad range of 2D materials with tailored properties which can be processed from liquids by established techniques such as spin coating, drop casting or printing. In turn, this will allow for the fabrication of multicomponent inorganic/organic hybrid systems using supramolecular chemistry. Such systems are of great interest for both fundamental studies and various applications, as synergistic effects between different classes of nanomaterials can be exploited.