新型氢键型二维层状材料MOHXenes的制备及高压研究

Two-dimensional (2D) layered materials have become one of the most highlighted scientific subjects worldwide due to their unique structures and versatile applications. Especially they have attracted immense attention of the high pressure research field. In our previous foundational work, we have found a novel type of hydrogen bonded 2D layered materials, MOHXenes, which can be a good model system for the high pressure studies of 2D layered materials. In this project, we intend to realize the controllable preparation of MOHXenes through multiple synthetic routes, and carry out systematic high pressure studies on MOHXenes by using various experimental techniques in parallel. Taking advantages of the mutual corroboration of the various experimental results, as well as those of the theoretical simulations, we intend to explore the pressure-dependent evolutions of the crystal structures and the spatial configuration of the interlayer hydrogen bonds of MOHXenes under high pressures. Simultaneously we intend to study the competition and collaboration between the interlayer hydrogen bonds and the intralayer strong chemical bonds. We want to elucidate the general effects of the compression behaviors of hydrogen bonds on the structural evolution and interlayer-intralayer interactions in these 2D layered materials. We also plan to explore the electrical transport behaviors of MOHXenes and their interactions with electromagnetic waves under high pressures. And consequently, we look forward to discover the general effects of high pressure on the electron energy band structures and the carrier characteristics, as well as the intrinsic nature of these effects. Through comparison with the high pressure study results of the van der Waals type 2D materials, we would like to summarize the general rules of the variations of the physical properties of 2D layered materials under high pressures, and to provide new insights and important experimental and theoretical reference data for the applications of 2D layered materials.

二维材料以其独特结构和广泛应用已成为世界范围的研究热点，尤其引起高压界的热切关注。申请者在前期工作基础上，发现一类新型氢键型二维层状材料MOHXenes，而且是二维材料高压研究的理想模型体系。本项目拟通过多种方式实现MOHXenes的可控制备，并采用多种原位高压实验技术对其进行系统的高压研究，通过不同高压实验结果的相互佐证，结合理论计算模拟，探索高压下MOHXenes的晶体结构、层间氢键构型随压力的演化过程，及压力与层间氢键、层内强化学键间的竞争、协同关系，揭示氢键的压缩行为对其结构演变过程、层间—层内相互作用的影响规律；探索其在高压下的电输运行为及其与电磁波的相互作用规律，揭示其电子能带结构、载流子特性等受压力调控的规律及物理根源。并与已有van der Waals型二维材料的高压研究结果的比对，总结高压下二维层状材料物理性质变化的共性规律，为其实际应用提供新思路和重要的实验与理论依据。

因其独特的成分和结构，二维材料展现出优异的性质和广泛的潜在应用，成为备受关注的研究热点之一。MOHXenes因其有别于van der Waals型二维材料的层间氢键，成为一类别具特色的研究二维材料压力响应的良好模型体系。本项目研究了氢键型二维层状材料MOHXenes的可控制备方法，在此基础上，采用多种原位高压实验技术，结合理论计算和模拟，对其进行了系统的高压研究。通过本项目的研究，建立了具有独立自主知识产权的制备新型氢键型二维层状材料MOHXenes的新方法，制备出了一系列成分和形貌可控、分散性好、结晶度高的MOHXenes准二维材料，揭示了其生长机制，为其潜在应用提供了必要的理论基础和实验数据；获得了MOHXenes中层间氢键强度及构型随压力的演化过程及其微观机制，揭示了高压调控下氢键与层间van der Waals相互作用、层内原子间共价/离子型强化学键之间的竞争与协同及其物理/化学本质，有助于构建出氢键空间构型的较为直观的图像，揭示氢键的压缩行为及其演化规律，并进而认识氢键的本质；探索了MOHXenes在高压下的相变序列、相变压力、高压相结构、状态方程和体弹模量等特性，深化了对其相变机制的认识，确定了MOHXenes中氢键与晶格压缩行为的内在关联，揭示了外加压力、内部层间氢键—层内强化学键等多种因素在决定其微观晶体结构、电子能带结构上的竞争、协同关系及其规律。