Preparation of Ni/C core-shell composite powders by electroless plating method
(1. Institute of High Temperature Ceramics, Zhengzhou University, Zhengzhou 450052, China;
2. College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, China)
2. College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, China)
Abstract: Ni/C core-shell composite powders were prepared by electroless nickel-plating. The effects of concentration of NiSO4, bathing temperature, ratio of hydrazine hydrate to NiSO4, pH of the solution, amounts of complexing reagent and surfactant, bath load of activated carbon and reaction time, and so on, on the preparation of Ni/C core-shell composite powders were studied. The results show that the principal factors for Ni/C composite powders preparation are bathing temperature, ratio of hydrazine hydrate to NiSO4 and pH of the solution. The optimum conditions are plating at 90 ℃ with pH10.7 and molar ratio of N2H4×H2O to Ni2+of 3.0. The plated nickel powders are observed to be sphere-like in morphology with size about 100 nm. The maximum dielectric loss of Ni/C core-shell composite powders is about 0.35, and its magnetic loss was low with value about 0 in 2−16 GHz.
Key words: Ni/C; core-shell powders; electroless plating; preparation