Preparation Of Boron Nitride And Titanium Nitride Nanomaterials

The aim of this dissertation is to explore the synthesis of boron nitride(BN) and transition metal nitrides(TiN) in the autoclave at 500—700℃,The morphologies of the as-prepared inorganic nanomaterials are characterized and the properties are investigated.The main contents are summarized as follows:1.(1) Nanocrystalline boron nitride(BN) is synthesized by co-reduction of NH₄Cl and H₃BO₃ using Mg as reductant at 600℃for 10 h。Through the analysis,and the sample is proved as h-BN.TEM images shows flake-like morphology with a mean size of about 100 nm in width and 600 nm in length;(2) Flaky boron nitride (BN) is prepared by co-reduction of NaBH₄ and NaN₃ using NH₄Cl or Fe as assistant at 500-550℃for 10 h,respectively。Through the analysis,the sample is proved as h-BN too,howerer,some curled into thin tubes,the diameter of tubes is about 500 nm and the wall thickness is about 10-20nm.(3) Boron nitride(BN) with flake-like morphology is synthesized by co-reduction of NaN₃ and H₃BO₃ using Mg as reductant at 500℃for 10 h.Through the analysis of XRD and TEM, the sample is h-BN and has comparative morphology of uniform size and particle films.2.(1) Nanocrystalline titanium nitride(TIN) is synthesized by the reaction of TiO₂ and NaNH₂ at 550℃for 10 h.When added to Co as catalyzer,TEM images show solide and hollowe balls morphology,while without Co,TEM images show particle morphology with uniform mean size;(2) Titanium nitride(TIN) nanocages is prepared by the reaction of TiO₂ and NaNH₂ at 600-650℃;(3) Titanium nitride (TIN) with nanocages morphology can also be observed when Mg and NH₄Cl substitute for NaNH₂ as reactant at 700℃for 10 h.Through the analysis of TEM, the morphology of the sample is showed as the solid and hollow nanocages mixed.