Nickel(III) oxide
Nickel (III) oxide is the inorganic compound with the formula Ni2O3. It is not well characterized,[1] and is sometimes referred to as black nickel oxide. Traces of Ni2O3 on nickel surfaces have been mentioned.[2][3]
Nickel (III) oxide has been studied theoretically since the early 1930s,[4] supporting its unstable nature at standard temperatures. A nanostructured pure phase of the material was synthesized and stabilized for the first time in 2015 from the reaction of nickel(II) nitrate with sodium hypochlorite and characterized using powder X-ray diffraction and electron microscopy.[5]