Uranyl hydroxide
Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO(OH) in the monomeric form and (UO)(OH) in the dimeric; both forms may exist in normal aqueous media. Uranyl hydroxide hydrate is precipitated as a colloidal yellowcake from oxidized uranium liquors near neutral pH.
Nickel compounds
Nickel hydroxides are used in nickel–cadmium and Nickel–metal hydride batteries.
Nickel(II) hydroxide Ni(OH), the main hydroxide of nickel is coloured apple green. It is known as the mineral theophrastite.
β-NiO(OH) is a black powder with nickel in the +3 oxidation state. It can be made by oxidising nickel nitrate in a cold alkaline solution with bromine. A mixed oxidation state hydroxide NiO(OH) is made if oxidation happens in a hot alkaline solution. A Ni hydroxide: nickel peroxide hydrate NiO, can be made by oxidising with alkaline peroxide. It is black, and unstable and oxidises water.