Uranate
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Benjah-bmm27
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'''Uranate''' is the chemical term for [[oxide]] [[ion|anion]]s of the element [[uranium]]. Examples of uranates include UO<sub>2</sub><sup>2+</sup>, UO<sub>3</sub><sup>2−</sup>, and UO<sub>4</sub><sup>2−</sup>.
The metal uranium forms several oxides:
*[[Uranium dioxide]] or uranium(IV) oxide (UO<sub>2</sub>, the mineral [[Uraninite]] or pitchblende)
*[[Uranium trioxide]] or uranium(VI) oxide (UO<sub>3</sub>)
*[[Triuranium octaoxide]] (U<sub>3</sub>O<sub>8</sub>, the mineral uranite, the most stable uranium oxide)
[[Yellowcake]], an intermediary product in uranium processing, also contains various uranium oxides.
==Applications==
===Catalysts===
Uranium oxides are known to have high efficiency and long-term stability when used to destroy [[volatile organic compound]]s (VOCs) when compared with some of the commercial [[catalyst]]s, such as [[precious metal]]s, [[titanium dioxide|TiO<sub>2</sub>]], and [[cobalt oxide|Co<sub>3</sub>O<sub>4</sub>]] 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''.)
===Semiconductors===
{{main|Uranium dioxide}}
Some uranium oxides, namely [[uranium dioxide]], have [[semiconductor]] properties similar to other [[semiconductor material]]s. 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 upset]]s. [[Schottky diode]]s made of uranium oxide and a [[p-n-p transistor]] of [[uranium dioxide]] were successfully demonstrated in a laboratory. [http://www.ornl.gov/~webworks/cppr/y2001/pres/109607_.pdf] [http://web.ead.anl.gov/uranium/mgmtuses/duuses/semiconductors/index.cfm]
[[Category:Uranates| ]]