Preparation And Properties Of Two Dimensional Material Of Mica And Metal Nanosheets

Ever since graphene was discovered,two dimensional material has always been attractive in the nano material area.Due to their unique structure and dimension,two dimensional materials show some better and completely new properties comparing to their original bulk material.The unusual properties of these materials associated with dimensionality and band structure impart them with strong potential for use in a wide range of applications in electronics,optoelectronics,catalysis,biomedicine,energy conversion and storage.On the other hand,a number of methods,including “bottom-up“and “top-down”,have been developed to prepare two dimensional minerals,metals and oxides.However,large-scale environmental-friendly production method with high efficiency is still needed.In this paper,we mainly focus on 2-D materials: Mica and 2-D metal.Verify and develop the suitable methods for the preparation of 2-D mica and metal respectively.The mechanical exfoliation was applied to mica nanosheets,obtaining the mica nanosheets with thickness of tens of nanometers by simply band tape strategy assisted with thermal release tape.Mica nanosheets with different thickness could be fabricated through different mechanical exfoliation times.AFM characterization exhibited that the thickness of mica nanosheets ranged from 10 nm to 100 nm At the same time,C-AFM with high voltage was used to measure the breakdown voltage of each mica nanosheet,observing that the breakdown field strength changed inversely with the thickness.As to 2-D metal,a general strategy to fabricate free-standing two-dimensional metallic nanosheets at room temperature was developped.By simply repeated folding and calendaring of two different metal foils,metal plates filled with nanosheets are obtained,after selected etching one of the two kinds of the metal,free standing metal nanosheets were fabricated.Up to now,Ag,Au and Fe nanosheets were prepared and systematically investigated.The thickness range from 1nm to 10 nm,and most nanosheets share this range of thickness.The mean lateral sizes of the nanosheets fabricated by this physical method are approximately 3-5 ?m,the dispersibility and purity turned to be good.The magnetic anisotropic behavior of the Fe nanosheets was verified by direct experimental evidence which matched well with the former theoretical calculations.Ag nanosheets also showed excellent photo-thermal properties.