Two-dimensional Hexagonal Boron Nitride Nanosheets：From Preparation To Surface Modification

Hexagonal boron nitride nanosheets(BNNSs)as a late model of two-dimension nano material,has rapidly permeated into various research field.Due to its outstanding properties in physics and chemistry,it becomes focus of the scientific research on boron nitride nano material.Similar to graphene,BNNSs has more excellent properties including the thermostability,resistant to corrosion,antioxidant and a wide band-gap,which make it to be widely used in high temperature semiconductor materials,photoelectric material,ceramic material,composite material and so on.At present,there are various preparation methods for graphene,but a few for BNNSs.Because the BN lamellas are formed by strong ionic bonding rather than the weak VDW force which result in the preparation methods for graphene cannot completely accommodate the BNNSs preparation.Therefore,the preparation of high-quality BNNSs becomes a huge challenge.In this paper,we mainly around prepared BNNSs and the boron nitride nanosheets/gold nanoparticle composite nanomaterial(BNNS/AuNP)and discussed its properties.In the first place,two-dimension BNNSs was prepared by inorganic chemistry stripping method,using mixture solution of sulfuric acid and orthophosphoric acid as reactive solvent,stirring the block of h-BN powder.The crystal structure of the prepared BNNSs is not damaged and there is no introduction of any impurities.In addition,the crystallinity of BNNSs is very good.In the second place,the BNNSs was prepared by differential centrifugation and obtained with different layers.Different atomic layer thickness and lateral size of BNNSs can be sorted by different centrifugation rates.The thickness of the atomic layer is basically in the 4-10 layer,and the lateral size is from 200 nm To 6 μm.The BNNSs have good ultraviolet-visible(UV-vis)absorption properties.Finally,using self-organization of block copolymer to prepar gold nano-particles(AuAPs),the size and space of AuNPs can be adjustabled.The boron nitridenanosheets/gold nanoparticle composite nanomaterial were prepared by modified to surface of BNNSs by chemical bond.In addition,we studied the effects of different gold nanoparticles size and different preparation methods on Surface-enhanced Raman scattering.