Fabrication and characterization of Ni-decorated h-BN powders with ChCl-EG ionic liquid as addition by electroless deposition

Electroless plating nickel particles on hexagonal boron nitride (h-BN) of ceramic powders are investigated in this paper. As comparison, the different additive concentration of choline chloride-ethylene glycol (ChCl-EG) ionic liquid (0g/L, 30g/L, 60g/L, 90g/L) is presented. The effects of ChCl-EG concentration are studied, including the surface morphologies, phase analysis of Ni-decorated h-BN powders, and the residual Ni2+ concentration is measured in electroless plating bath. It is demonstrated that the deposition phenomena of nickel particles on h-BN surface is changed with the addition of ChCl-EG. When the concentration of ChCl-EG is 30g/L, the Ni particles on h-BN surface are in dispersed and spheroid state with the average size of 10-1000nm. It can be found that 30g/L ChCl-EG is conducive to the arise of deposition phenomena, which is the formation of the single nickel particle on h-BN surface. Besides, more Ni particles are deposited on h-BN surface with the increase of plating nickel times, which is characterized with scanning electron microscope (SEM) and transmission electron microscope (TEM). Furthermore, the deposition phenomenon and growth mechanism are proposed without and with ChCl-EG as additive to further elaborate the formation of Ni particles on h-BN surface.

本文针对陶瓷粉末六方氮化硼（h-BN）表面负载化学镀镍颗粒开展研究。为进行对照，本文设置了氯化胆碱-乙二醇（ChCl-EG）离子液体的不同添加浓度梯度：0g/L、30g/L、60g/L、90g/L。本文研究了ChCl-EG浓度对负载镍的h-BN粉末的表面形貌、物相组成的影响，并测定了化学镀镀液中的残留Ni²+浓度。研究证实，ChCl-EG的添加会改变h-BN表面的镍颗粒沉积行为。当ChCl-EG浓度为30g/L时，h-BN表面的镍颗粒呈分散球形形貌，平均粒径为10~1000nm。研究发现，30g/L的ChCl-EG可有效促进沉积行为的发生，实现h-BN表面单个镍颗粒的均匀形成。此外，随着化学镀次数的增加，h-BN表面沉积的镍颗粒数量增多，该结果通过扫描电子显微镜（SEM）与透射电子显微镜（TEM）进行了表征。进一步，本文分别针对未添加与添加ChCl-EG的体系，提出了镍颗粒的沉积现象与生长机理，以深入阐明h-BN表面镍颗粒的形成过程。