Copper Oxide Assisted Synthesis Of Hexagonal Boron Nitride Nanomaterials

Hexagonal boron nitride (h-BN), which structurally resembles graphite, it is well known for its advantageous properties such as high temperature stability, extreme hardness, acid-base resistance, oxidation resistance, high thermal conductivity and insulativity. Those advantageous properties make h-BN wide applications as hydrogen storage media, catalyst supports under relatively harsh conditions, reinforced filler in heat conductive materials and inorganic-organic composite materials. Three different kinds of hexagonal boron nitride nanomaterials are synthesized by adjusting reaction materials, reaction time and amount of copper oxide (CuO).1. Hexagonal boron nitride nanoparticles were synthesized via a simple reaction of boric acid, ammonium chloride, potassium chloride and a certain amount of CuO in high temperature tube furnace. Morphology and crystal structure of h-BN nanomaterials were characterized and analyzed by SEM, TEM, XRD, FTIR, XPS, BET etc, aqueous dispersion and stability of h-BN nanoparticles were investigated further. Copper oxide was found to affect particle size, surface area and surface property of the BN nanoparticles, camparing with boron nitride nanoparticles synthesized without the precence of copper oxide, the average size of the spherical h-EN nanoparticles synthesized with the addition of CuO was about30nm, the h-BN had a high surface area of75m2g-1, the zeta potentials of BN were between-30and-50mV in the pH range of4to10, the h-BN nanoparticles were well-dispersed and stable in aqueous solution.2. Quadrangular boron nitride nanowires were synthesized by increasing amount of CuO and prolonging reaction time. Various reaction conditions including reaction temperature, amount of copper oxide and reaction time had effects on the formation of nanowires. Length and width of the BN nanowires were about25μm and100nm, the ratio of l/d was about250:1, the boron nitride nanowires were rarely reported. However, hexagonal boron nitride nanosheets could be synthesized using boron acid, potassium chloride and copper oxide powders as precursors under ammonia atmosphere, thickness of uniform boron nitride nanosheets was about30nm.