Electroless deposition of Ni nanoparticles on micron-sized boron carbide particles: Physicochemical and oxidation properties

Abstract

The present work describes the electroless deposition of Ni nanoparticles on micron sized (10 μm) boron carbide particles at room temperature. The weight of the boron carbide particles varied in relation to the other parameters during electroless deposition. A uniform and continuous nanolayer of Ni nanoparticles changed into a discontinuous layer, with irregular distribution and insignificant presence of Ni nanoparticles, as the weight of the boron carbide increased. The EDS measurement, elemental mapping and line scanning profile results showed a decrease in Ni percentage, as the weight of boron carbide increased in the samples. Further, FIB cross-sectional SEM images demonstrated a core-shell like structure of Ni coated boron carbide particle, when the weight of boron carbide was low in the sample. XRD showed the nanocrystalline nature of Ni-particles, and the presence of Ni, B and C elements was confirmed by XPS analysis. When thermogravimetric analysis was conducted in air atmosphere, the boron carbide, Ni nanoparticles and Ni-coated boron carbide samples exhibited oxidation at high temperature accompanied by weight gain. After being coated with Ni nanoparticles, even a small amount of Ni, the oxidation temperature of the boron carbide shifted to a lower temperature, with enhanced exothermic reaction as well as higher weight gain.