Nickel oxide, also known as NiO, is the main oxide of nickel. It is rare in the mineralogical form (bunsenite) but millions of kilograms are produced each year as an intermediate for nickel alloy production.
For making electrical ceramics such as thermistors and varistors e.g. ferrites (nickel-zinc ferrite) Pigments for ceramic, glasses and glazes
In the electrochemical industry, a wide variety of electrodes are prepared by coating a thin layer of nickel oxide on a substrate, usually carbon steel or copper, and then heating at an elevated temperature. The resulting conductive network is typically a recipitative material containing a varying amount of cobalt hydroxide and zinc hydroxide, each usually between 1 and 5 wt%.
Additives and cations:
A number of cations, including lithium, cadmium, and zinc, can be added to the paste to enhance its performance characteristics such as conductivity and oxygen overpotential. The most common additive is cobalt hydroxide. Other additives may include calcium hydroxide, fluoride, sulfide, or oxide and yttrium oxide.
Sintering of nickel oxide nanoparticles:
Various methods for preparing NiO nanostructured materials have been developed, which include conventional sintering and electrospun nickel hydroxide through a sol-gel route . These methods are economical and can be used to produce nanoparticles with varied morphologies and microstructures that can be used for sensing, catalytic, magnetic, and photovoltaic domains.
Cyclic voltammetry of NiO:
A cyclic voltammetric study was performed on NiO prepared via conventional sintering and annealing at different temperatures (Fig. 1). The results showed that the process of oxidation is kinetically limited by charge transfer at the electrode/electrolyte interface. The voltammograms of both bare and dye-sensitized NiO presented a linear dependence of the current intensity peaks with the scan rate.