Magnetic And Photocatalytic Properties Of Two-dimensional Self-assembly Materials Based On TM@Si₁₆?TM=Ta,Ti? Superatom

In recent years,the miniaturization of electronic devices has made ultra-thin two-dimensional?2D?materials highly concerned.The development of spintronics urgently needs some ultra-thin 2D ferromagnetic materials with excellent performance and high Curie temperature.So far,most reported ultra-thin 2D materials have been obtained only by peeling off layered compounds from a top-down approach,limiting their large-scale applications in increasingly sophisticated technologies such as spintronics.With the development of nanotechnology,it has become possible to design and assemble new-type nanomaterials with specific functions by using a new type of nanostructure-clusters as building units,through a"bottom-up"method.This paper first designed and assembled several low-lying Ta@Si₁₆2D self-assembled structures using density functional theory?DFT?and molecular dynamics?MD?simulations based on the experimentally synthesized Ta@Si₁₆superatomic clusters.On the basis of studying their stability and electronic structure,explored the potential applications of these assembled structures in magnetic and photocatalysis.The results show that Ta@Si₁₆superatoms can maintain their own structural framework in all structures,and can be stable at room temperature.The hexagonal honeycomb lattice Hex-d and the two Ta@Si₁₆/C₆₀interfaces(Line-C₆₀-2D and Face-C₆₀-2D)are new semiconductors.Their magnetic properties can be controlled by adsorption sites.The line contact Ta@Si₁₆/C₆₀interface(Line-C₆₀-2D)has intrinsic ferromagnetism,and the Curie temperature can reach 294K;the face contact Ta@Si₁₆/C₆₀interface(Face-C₆₀-2D)has a certain photocatalytic activity.The graphene-supported Ta@Si₁₆2D array has a long-range magnetic coupling.When the supercell size reaches 5×5,the system has weak ferromagnetic coupling characteristics.Next,we also studied the geometric and electronic structure and photocatalytic properties of the 2D interface of Ti@Si₁₆cluster adsorbed on the C₆₀surface by DFT,the results show that all Ti@Si₁₆/C₆₀2D interfaces have lower energy and are more stable than Ti@Si₁₆-C₆₀dimer.Among them,Face3-6 2D structure is new semiconductor with band gap of 1.89 e V,which is good potential solar photocatalyst.This study demonstrates that TM@Si₁₆clusters can be used as a promising building block primitive to construct and assemble new 2D nanomaterials with potential applications in spintronic devices,quantum computing,new clean energy and other fields.