Authors: Haifeng Lv | Xiaojun Wu
Source: Chinese Science Bulletin (Chinese Version) (article, 2023-10-01)
Field: Materials Science — Materials Chemistry

Molecular design of low-dimensional functional materials based on first-principles calculation <p indent="0mm">In recent decades, low-dimensional materials have encountered great advances in scientific research and practical applications, which have attracted much attentions from researchers worldwide. Due to the significant quantum confinement effect, low-dimensional materials usually exhibit superior physical and chemical properties to their bulk counterpart, rendering them great potential in many applications, such as catalysts, nanoelectronics, spintronics, and energy, but how to realize specific structures and functionalities is the basis for their practical applications. Theoretical simulation of low-dimensional materials is of particular interest for the discovery of new materials because it provides an effective approach to create a direct relationship between their structural information and physical properties (especially the electronic structure of low-dimensional materials) at the atomic level by using modern computational methods, mainly represented by first-principles calculations. In past decades, substantial efforts have been devoted to the theoretical design of low-dimensional materials, providing some hints for experimental studies to accelerate the discovery of new materials, such as global structure prediction, multiscale simulation, and machine-learning based material design. However, it is a major challenge to predict/design the structure of low-dimensional materials with targeted functionalities merely starting from their composition. One major hinderance is the extremely complicated potential surface, with its complexity increasing exponentially with the number of atoms, resulting in huge computational effort to predict the global stable structures of materials and establish a reliable structure/property relationship only from their composition to directly design materials with targeted functionalities. In addition, the theoretical design of low-dimensional materials with targeted functionalities starting from their compositions, i.e., element and number of atoms, usually requires building an explicit structure with specific atoms, raising great challenges to experimental synthesis and postprocessing methods at the nanoscale. Molecule is the basic unit of substance with complete chemical properties of that substance that can be used as building block to develop low-dimensional materials, feature spanning chemical space, controllable synthesis, porosity, multifunctional properties, and various postsynthetic methods. Compared with building low-dimensional material with atoms, the complexity of the potential energy surface can be significantly reduced if building low-dimensional materials with molecules, of which the structures are constrained by the basic bonding theory between molecular building blocks. Additionally, the basic chemical function of molecules can be integrated into low-dimensional materials, providing a practical strategy to design low-dimensional materials with targeted functionalities with specific molecular building blocks. Meanwhile, polycondensation and self-assembly reactions provide synthetic methods to construct molecule-based low-dimensional materials using predesigned primary and high-order structures, leading to modular synthesis. In past decades, increasing attention has been devoted to molecule-based low-dimensional materials, with wide applications in gas adsorption or separation, luminescence, sensors, energy storage, transport media, catalysis, magnets, and biomaterials. The rational design of low-dimensional materials based on molecular building blocks with specific configurations and functionalities has also attracted theoretical interest to describe the interactions between molecule-based units, and create a relationship between low-dimensional materials and molecular building blocks to realize the inverse design of low-dimensional materials with targeted functionalities. This paper aims to provide an overview of low-dimensional material design based on the joint molecular design strategy and first-principles electronic structure calculation method from theoretical aspects, including the structural prediction of two-dimensional allotropic crystals, a series of low-dimensional photocatalysts, and low-dimensional spintronics, in which the interplay between the properties of molecules and functionalities of low-dimensional materials is emphasized. We conclude with the benefits and challenges of molecule-based low-dimensional materials and outline the efforts to bridge the molecules and low-dimensional materials. Computer science ; Materials science 2D Materials and Applications ; Advanced Photocatalysis Techniques ; Machine Learning in Materials Science