Uranate

From Wikipedia, the free encyclopedia

Uranate is the chemical term for oxide anions of the element uranium. Examples of uranates include UO₂⁻², UO₃⁻², and UO₄⁻².

The metal uranium forms several oxides:

• Uranium dioxide or uranium(IV) oxide (UO₂, the mineral Uraninite or pitchblende)
• Uranium trioxide or uranium(VI) oxide (UO₃)
• Triuranium octaoxide (U₃O₈, the mineral uranite, the most stable uranium oxide)

Yellowcake, an intermediary product in uranium processing, also contains various uranium oxides.

[edit] Applications

[edit] Catalysts

Uranium oxides are known to have high efficiency and long-term stability when used to destroy volatile organic compounds (VOCs) when compared with some of the commercial catalysts, such as precious metals, TiO₂, and Co₃O₄ catalysts. Much research is being done in this area, depleted uranium being favoured for the uranium component due to its low radioactivity. (Hutchings, G. J., et. al., AUranium-Oxide-Based Catalysts for the Destruction of Volatile Chloro-Organic compounds,@ Nature, 384, pp. 341B343, 1996.)

[edit] Semiconductors

Main article: Uranium dioxide

Some uranium oxides, namely uranium dioxide, have semiconductor properties similar to other semiconductor materials. Its band gap lies at around 1.3 eV. Its Seebeck coefficient is very high, making it a promising material for thermoelectric applications. It is also capable of withstanding high temperatures.

The low level of alpha radiation produced in the material is a cause of electronic noise, causing multiple single-event upsets. Schottky diodes made of uranium oxide and a p-n-p transistor of uranium dioxide were successfully demonstrated in a laboratory. [1] [2]