How Is Nickel(II) Oxide Prepared?

Nickel(II) oxide can be prepared by heating nickel(II) hydroxide, nickel carbonate, or nickel(II) nitrate in air at a temperature above 300°C until the desired oxide is formed. The reaction can be represented as:

Ni(OH)2 → NiO + H2O

NiCO3 → NiO + CO2

Ni(NO3)2 → NiO + 2NO2 + 1/2O2

The resulting nickel(II) oxide can be further purified by washing it with water to remove any impurities before drying and storing.