Synthesis and Characterization of Nickel, Cobalt and Ni-Doped Cobalt Hydroxides

Abstract

In the current research work nickel hydroxide, cobalt hydroxide and Ni-doped cobalt hydroxide powders were synthesized through the precipitation method by using 0.5 molar sodium hydroxide solution, 1 molar nickel chloride hexahydrate, cobalt chloride hexahydrate solution respectively along with hydrazine hydrate solution. Morphology of as-synthesised powders indicated spherical structure of nickel hydroxide and polyhedral structure of cobalt hydroxide. The surface morphology of the doped sample was similar to cobalt hydroxide because of higher amount of cobalt present in the doped sample. The DSC-TG curve shows that there is maximum percentage of mass loss at around 3000 C which is due to conversion of nickel hydroxide into nickel oxide and for cobalt hydroxide and the doped sample the weight loss happened around 1700 C.The photoluminescence test of the hydroxide and oxide samples are carried out. The result showed all the hydroxides have photoluminescence property in the violet-blue region. But among the calcined powders (300 °C), calcined nickel hydroxides and Ni-doped cobalt hydroxide showed the same violet-blue luminescence.