Ni2O3

Nickel(III) oxide, with the chemical formula Ni2O3, is a chemical compound. It is one of the oxides of nickel. Nickel is a transition metal, and its oxides exhibit various oxidation states, with Ni2O3 representing nickel in the +3 oxidation state. This compound is less common and generally less stable than nickel(II) oxide (NiO).

Ni2O3 is typically encountered as a black or dark brown solid. Its precise stoichiometry can vary, and it may exist as a non-stoichiometric compound, meaning the ratio of nickel to oxygen is not exactly 2:3. This non-stoichiometry often arises from the presence of vacancies in the crystal lattice or interstitial atoms. The stability of Ni2O3 is influenced by factors such as temperature and the surrounding chemical environment. Under certain conditions, it can decompose to form nickel(II) oxide and oxygen.

The synthesis of nickel(III) oxide can be achieved through various oxidation methods. One common approach involves the strong oxidation of nickel(II) compounds. For example, heating nickel(II) hydroxide or nickel(II) oxide in the presence of an oxidizing agent, or under an oxygen-rich atmosphere at elevated temperatures, can lead to the formation of Ni2O3. It is also observed in some electrochemical processes involving nickel. Due to its higher oxidation state, Ni2O3 can act as an oxidizing agent. Its applications are relatively limited compared to NiO, but it finds some use in areas where a strong oxidizing nickel compound is required.