Synthesis And Properties Of Boron Nitride Nanomaterials

Hexagonal boron nitride (h-BN) is a layered material with a graphite-like structure.As the structural analogue of a carbon nanotube (CNT), a BN nanotube (BNNT) was first predicted in 1994. Since then, it has attracted considerable attention for their particular properties. BNNT is an electrical insulator with a band gap of ca. 5eV, basically independent of tube geometry. Besides, BNNTs possess a high chemical stability, excellent mechanical properties, and high thermal conductivity. The same advantages are likely applicable to a graphene analogue-a monatomic layer of a hexagonal BN. The unique structure induced properties of BNNTs bring a series of opportunities for their potential applications as hydrogen storage media, biological probes, piezoelectric materials, composite reinforcements and harsh-environment semiconductor devices. These promises have motivated intense research efforts seeking to develop synthetic strategies for preparing BNNTs. The main research of BN nanomaterial in this paper mainly involved three fields:systhsized BNNTs, composite of BNNSs and biosensor based on Au anchored on BNNSs.1. Various shaped boron nitride nanotubes(BNNTs)have been synthesized by CVD method.The structure and chemical composition of as-synthesizd BNNTs are extensively characterized by X-ray diffraction, Scanning electron microscopy, high-resolution transmission.When the BNNTs growth temperature at 800℃, the SEM images reveal that the products actually consists of three morphologies of 1D nanostructures. Two nanostructures of BNNTs grow partially vertical aligned to the Si substrate, the other do not. Higher growth temperature at 1000℃, Uniform BNNTs with almost open tips were synthesized.We also analyse the grouth mechanism of BN nanotubes.Our experiments support a different growth model by kinds of catalyst.2. The composites of BN nanosheets (BNNSs) and polythiophene(PT) were prepared by a simple method.The thermogravimetric analysis (TGA) shows about 10wt% weight loss of the BNNSs/PT composite between 320℃and 550℃, corresponding to the complete decomposition of PT.Proof of the strong interactions between BNNSs and PT is given by Raman. UV-Vis absorption, and XRD experiments. The present studies may help BN nanosheets application as an effective composite additive in PT in order to improve the polymer processing and handling.3. Au modified BNNSs has been obtained by a simple hydrothermal method. We employ the high-loading Au NPs on BNNSs as the electrochemical enhanced material for H2O2 sensing. The wide linear ranges and low detection limits are obtained.