Uranyl hydroxide

Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO2(OH)2 in the monomeric form and (UO2)2(OH)2 in the dimeric; both isomers may exist in normal aqueous media. Uranyl hydroxide hydrate is precipitated as a colloidal yellowcake from oxidized uranium liquors near neutral pH.

Uranyl hydroxide was once used in glassmaking and ceramics in the colouring of the vitreous phases and the preparation of pigments for high temperature firing. The introduction of alkaline diuranates into glasses leads to yellow by transmission, green by reflection; moreover these glasses become dichroic and fluorescent under ultraviolet rays. The material conducts protons and when pressed under steadily increasing pressure (subsequently gradually released) and may find use as a fuel cell component.(United States Patent 4179491)

Uranyl hydroxide is teratogenic and radioactive, and should be handled with the appropriate care.