Nickel oxide (NiO) is widely used as a catalyst in chemical reactions, particularly in oxidation processes and as a precursor for nickel-based catalysts in hydrogenation and steam reforming for hydrogen production. It plays a crucial role in the positive electrodes of nickel-based batteries, such as nickel-cadmium (Ni-Cd) and nickel-metal hydride (Ni-MH), owing to its excellent electrochemical properties for energy storage and release.

In ceramics and glass production, it imparts green coloration. Nickel oxide is also utilized in manufacturing electronic components, resistors, fuel cells, sensors, and magnetic materials due to its electrical and magnetic properties. Additionally, it serves as a coating to improve corrosion resistance and high-temperature durability.