Nickel oxide (Ni₂O₃) has been referred to in the literature but is not a well characterised compound. The substance black nickel oxide is sometimes described as being Ni₂O₃ however the composition quoted by suppliers has a nickel content of around 77% by weight whereas Ni₂O₃ would have 70.98% Ni by weight, and may be non-stoichiometric NiO

Nickel(II) oxide

Nickel oxide is the chemical compound with the formula NiO. It is notable as being the only well characterized oxide of nickel . The mineralogical form of NiO, bunsenite, is very rare. It is classified as a basic metal oxide...

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plus is fable 3
There are references in the literature to traces of Ni₂O₃ on nickel surfaces, and as intermediates in nickel oxidation, e.g. .

Nickel oxide hydroxide

The related nickel oxide hydroxide (NiOOH) can be prepared by reaction of nickel(II) chloride

Nickel(II) chloride

Nickel chloride , is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. It is very rarely found in nature as mineral nickelbischofite. A dihydrate is also known. In general nickel chloride, in various forms, is the most important source of...

 with sodium hypochlorite; the sodium hypochlorite functions as an oxidizing agent

Oxidizing agent

An oxidizing agent can be defined as a substance that removes electrons from another reactant in a redox chemical reaction...

. In one modification the compound is used in a catalytic amount with bleach in stoichometric amount in the oxidation of benzyl alcohol

Benzyl alcohol

Benzyl alcohol is an organic compound with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn", thus benzyl alcohol is denoted as BnOH. Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful solvent due to its polarity, low toxicity, and low vapor...

 to benzoic acid

Benzoic acid

Benzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...

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or in double oxidation of 3-butenoic acid to fumaric acid

Fumaric acid

Fumaric acid or trans-butenedioic acid is the chemical compound with the formula HO2CCH=CHCO2H. This white crystalline compound is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid. In fumaric acid the carboxylic acid groups are trans and in maleic acid they are cis...

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External links

• Reade Advanced Materials - Nickel oxide