▎ 摘　　要

NOVELTY - Preparing boron carbide nanoparticle comprises (1) taking boron source, carbon source and additives according to molar ratio (1-10):1:(0.001-0.1), and obtaining mixture A after mixing, (2) ultrasonically dissolving mixture A in solvent to obtain slurry B according to mass volume ratio of 1 g:(5-1000) ml, (3) placing obtained slurry B in hydrogen chloride (HCl) atmosphere, and heating and drying it at 30-300 degrees C for 0.2-24 hours to obtain dry mixture C, (4) placing dry mixture C in graphite crucible, heating it to 700-1700 degrees C in high-temperature furnace under inert atmosphere and keeping it for 0.1-6 hours, cooling in furnace, obtaining boron carbide powder, finishing preparation of boron carbide nanoparticles, where in the step (1), the boron source is crystalline boron, ammonium fluoroborate, boric acid, metaboric acid, pyroboric acid or trimethyl borate. USE - The method is useful for preparing boron carbide nanoparticle. ADVANTAGE - The nanoparticle: has nanometer scale, uniform particle size, high purity, low energy consumption during preparation, and no environmental pollution; is economical; can be mass-produced industrially; forms homogeneous mixture; controls the growth process of boron carbide under the action of the shape regulator magnesium chloride; realizes the preparation of nano-scale particles; and adjusts the size according to the ratio of the reactants and the addition amount of the shape regulator. DETAILED DESCRIPTION - Preparing boron carbide nanoparticle comprises (1) taking boron source, carbon source and additives according to molar ratio (1-10):1:(0.001-0.1), and obtaining mixture A after mixing, (2) ultrasonically dissolving mixture A in solvent to obtain slurry B according to mass volume ratio of 1 g:(5-1000) ml, (3) placing obtained slurry B in hydrogen chloride (HCl) atmosphere, and heating and drying it at 30-300 degrees C for 0.2-24 hours to obtain dry mixture C, (4) placing dry mixture C in graphite crucible, heating it to 700-1700 degrees C in high-temperature furnace under inert atmosphere and keeping it for 0.1-6 hours, cooling in furnace, obtaining boron carbide powder, finishing preparation of boron carbide nanoparticles, where in the step (1), the boron source is crystalline boron, ammonium fluoroborate, boric acid, metaboric acid, pyroboric acid or trimethyl borate, the carbon source is flake graphite, microcrystalline graphite, acetylene black, activated carbon, graphene, carbon nanotubes, hollow carbon spheres or carbon black, the additive is magnesium chloride, and in the step (2), the solvent is deionized water, absolute ethanol, glycerin, ethers or essential oils.