摘要：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。

关键词： 水热氢还原；核壳结构；复合粉末

Abstract：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. 

Keywords： hydrothermal hydrogen reduction； core-shell structure； composite particle