Preparation Of Boron Nitride Nanotubes By Nano Scale Catalyst And Its Modification

Boron Nitride Nanotube(BNNT)has a high resistance to oxidation,good chemical and thermal stability.The material has high research values on many applications such as nano energy collection,aerospace detector,space energy utilization,nanoelectronic devices,sensor networks,Radiation shielding and other fields.Although the BNNT electrical characteristics are not subject to chirality and diameter changes,the bandgap width is high,seriously restricting its applications in the electrical field.But can be through the doping and surface modification and functional methods of its artificial forbidden band width control to improve its electrical characteristics.The excellent properties of BNNTs have promoted the application of two-dimensional BNNT films.However,there are many problems in the preparation of two-dimensional BNNT films.There are problems such as complex operation,low purity and low yield,resulting in the researches on two-dimensional BNNT thin film progressing slowly.At present,the researches on BNNT thin films are mainly focused on the researches of composite materials.The research on pure BNNT films is rarely studied.Based on the above problems,the following researches are carried out: 1)The nano scale metal oxide catalysts are used to optimize the catalytic paths and the experimental steps are simplified to realize the high purity and high yield preparation of BNNT.2)Nanostructured Al2O3 was used as catalyst to prepare BNNT,and the boron nitride nanotube film was obtained by mechanical stripping method.The operation was simple and feasible.What’s more,we also provide a crude purification method and obtain the large area of self supported BNNT film with high purity and characterization;3)The modification of the BNNT synthesized above are investigated.That is,the use of magnetron sputtering method,as well as the surface modification of BN nanotubes by carrying out the special metal particles on the surface.and the condensation reaction of the activator and BNNT was carried out.The BNNT surface was suspended with-CF3 organic functional groups.4)The BNNT films were analyzed by cantilever method and also analyed the piezoelectricitythe of the BNNT films.After the systematic study and analysis,the following conclusions were obtained:the nano scale catalyst was used to assist the growth of BNNT,and the boron nitride nanotubes with high purity and high yield could be obtained.For the first time,mechanical stripping was used to obtain large area,flexible BNNT thin films were prepared.The surface modification of Au and Ni metal particles and the chemical modification of-CF3 organic functional groups were completed and their piezoelectric properties were studied.These studies promoted the development of BNNT and its thin films,which improves its potential value and provides reference value for the future application of boron nitride nanomaterials.