Control The Synthesis And Study Of The Boride, Nitride And Phosphide Nanomaterials

The aim of this dissertation is to explore the synthesis of boron nitride (BN), boron phosphide (BP), transition metal borides (TiB₂ ZrB₂ HfB₂), phosphorus nitride (P₃N₅), titaniun nitride(TiN) and metal phosphides (GaP ZrP) under the condition of low temperature or room temperature. The as-prepared inorganic nanomaterials are characterized and investigated. The major contents can be summarized as follows:1. Nanocrystalline boron nitride (BN) is synthesized by co-reduction of NH₄Cl and BBr₃ using Na as reductant. TEM images showed flake-like and hollow spherical morphology. The morphologies of solid balls, hollow spheres, tubes, bamboo-like tubes and crossing-like tubes can be observed when NaBF₄ substitute for BBr₃ as reactant.Nanocrystalline BN is also prepared by the reaction of BBr₃ and NaN₃ at 350℃ The morphologies of particles, needles, flakes and solid balls were controlled by solvothermal growth using benzene as solvent.2. Nanocrystalline BP TiB₂ ZrB₂ HfB₂ are prepared by the reaction of chloride (PCl₃ TiCl₄ ZrCl₄ HfCl₄) or TiO₂ with NaBH₄ in an autoclave. TEM images show particle morphology with average size of 10-30 nm for the powder obtained at 600℃.TiB₂ or ZrB₂ are also prepared by using Ti (or TiCl₄) and BBr₃ (or NaBF₄) as reactants, and Na as reductant at 400℃. TEM image shows particle morphology with uniform average size.3. Amorphous phosphorus nitride (P₃N₅) or cubic TiN hollow spheres are synthesized via reacting PCl₃ or TiCU with NaNH₂ at room temperature. TEM images show the hollow spheres. XPS is used to determine the molar ratio of 1:1.60 for P: N, close to that of P3N5 (1:1.67). In this process PCl₃ or TiCl₄ droplets may serve as a template with the shells formed near the liquid-solid interface.