Structures, properties and application of 2D monoelemental materials (Xenes) as graphene analogues under defect engineering

Abstract From the group-IIIA (borophene), to the group-IVA (silicene, germanene and stanine), as well as the group-VA (phosphorene, arsenene, antimonene and bismuthene) and even the group-VIA (selenene and tellurene nanosheets), these two-dimensional (2D) monoelemental materials are highly similar to graphene in lattice structure, and they can also be collectively referred to as Xenes. However, the unique specific atomic arrangement of these materials gives rise to a vast diversity of properties, and these single element 2D materials as graphene analogues are the most chemically tractable materials for synthetic exploration, thus attracting widespread attention and research. Intrinsic defects, as an defects inevitably introduced in the of experimental preparation, and extrinsic defects, as an artificially introduced and controllable way, both of them can effectively improve the environmental stability of single element materials and regulate the properties of Xenes. Herein, a review of the historical work about the properties and application of defective 2D monoelemental materials is presented. Based on the structure and properties of original single element 2D materials, the change of electronic and optoelectronic properties of these materials from different main groups under the action of different defects are classified and compared. In addition, the existing methods of realizing defects of 2D Xenes-based materials are summarized, and the application of the defects engineering in the field of optoelectronic devices, energy storage and conversion, catalysts as well are also comprehensively searched and reviewed. Finally, this review provides the prospect and challenge for the preparation and application of defective 2D monoelemental materials on the basis of the current research and development.