水热氢还原法制备镍包覆六方氮化硼复合粉末

采用水热氢还原法,在氨水-柠檬酸钠双络合体系中制备高纯度的镍包覆六方氮化硼复合粉末,探讨反应温度、搅拌速度、氢分压、催化剂以及络合剂等因素对复合粉末包覆效果的影响。结果表明:在搅拌速度为700 r/min、NH3与Ni的物质的量比为2∶1、温度为110～120℃、氢分压为1.5～2.0 MPa、PdCl2质量浓度为0.05 g/L、柠檬酸钠的质量浓度为32.8 g/L的条件下,可制得较理想的镍包覆六方氮化硼复合粉末。

Preparation of Nickel-coated Hexagonal BN Particles by Hydrothermal Hydrogen Reduction

Ni coated hexagonal BN particles were prepared by hydrothermal reduction with hydrogen using ammonia-sodium citrate complex system.The effects of temperature,agitation,the partial pressure of hydrogen,the catalyzer and chelators on the coating were discussed.The optimum reaction conditions were proposed as follows: the molar ratio of NH3 and Ni was 2 ∶ 1,the reaction temperature was 110～120 ℃,the hydrigen pressure was 1.5～2.0 MPa,the amount of catalyzer PdCl2 was 0.05 g/L,the dosage of sodium citrate complexing agents was 32.8 g/L and the stirring speed was 700 r/min.