Method for preparing hexagonal boron nitride nano composite structure

Abstract

As an important III-V main group compound, hexagonal boron nitride (h-BN) has multiple excellent physical and chemical properties, such as high-temperature resistance, oxidation resistance, corrosion resistance, self-lubrication and high thermal conductivity, and can be widely used in the fields of chemical industry, machinery, electronics, aerospaces, and the like. In recent years, a research on BN is relatively focused on BN nanotubes; by contrast, the research on BN nanowires is little, and a report on relevant BN micro-nano composite structures is rarer. The novel BN micro-nano composite structure is synthesized by taking amorphous boron powder, ferric chloride hexahydrate, absolute ethyl alcohol, high-purity nitrogen and liquid ammonia as raw materials. The synthetic method is simple in technology; the raw materials are nontoxic, environment-friendly and low in cost; the product purity is high; the yield is high; no purification is required; and scale production is facilitated. In addition, the novel BN micro-nano composite structure has a very high specific surface area, and has very wide development and application prospects in the fields of catalyst carrier materials, novel energy storage materials, ceramic compound materials and polymer composites.

Description

technical field [0001] The invention relates to a method for preparing a boron nitride micro-nano composite structure, in particular to a method for preparing a hexagonal boron nitride micro-nano composite structure. Background technique [0002] Boron Nitride (Boron Nitride molecular formula BN, molecular weight 24.81, theoretical density 2.27g / cm 3 ) is a substance composed of nitrogen atoms and boron atoms. The chemical composition is 43.6% boron and 56.4% nitrogen, and crystalline BN has four structures: hexagonal boron nitride (h-BN), rhombohedral boron nitride (r-BN), cubic boron nitride (c-BN ) and close-packed hexagonal boron nitride (w-BN / wurtzite boron nitride). [0003] Hexagonal boron nitride has no obvious melting point. It sublimes at 3000°C in 0.1MPa nitrogen, and has a melting point of 3000°C in inert gas. , Poor stability in oxygen atmosphere, use temperature below 1000℃. Hexagonal boron nitride is insoluble in cold water. When the water is boiled, it hy...

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Problems solved by technology

[0003] Hexagonal boron nitride has no obvious melting point. It sublimes at 3000°C in 0.1MPa nitrogen, and has a melting point of 3000°C in inert gas. , Poor stability in oxygen atmosphere, use temperature below 1000℃

[0014] However, in the current prior art, a large number of synthetic methods have been used for the synthesis of boron nitride nanostructures, for example, metal-catalyzed method, carbothermal reduction method, pyrolysis method, ball milling-annealing method, pyrolysis method and ammonia gas direct Nitriding method, etc., the steps of the above method are cumbersome, the purity of the product obtained is low, and a large amount of impurities coexist

Other methods, such as arc discharge method, electron beam radiation method, laser evaporation method, chemical vapor deposition method, laser ablation method, etc., rely on large and expensive equipment and the output of the resulting product is small

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