Copper(I) oxide

Last updated
Copper(I) oxide
CopperIoxide.jpg
Copper(I)-oxide-unit-cell-A-3D-balls.png
Copper(I)-oxide-xtal-3x3x3-3D-bs-17.png
Names
IUPAC name
Copper(I) oxide
Other names
Cuprous oxide
Dicopper oxide
Cuprite
Red copper oxide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.013.883 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 215-270-7
KEGG
PubChem CID
RTECS number
  • GL8050000
UNII
  • InChI=1S/2Cu.O/q2*+1;-2 Yes check.svgY
    Key: KRFJLUBVMFXRPN-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/2Cu.O/rCu2O/c1-3-2
    Key: BERDEBHAJNAUOM-YQWGQOGZAF
  • InChI=1/2Cu.O/q2*+1;-2
    Key: KRFJLUBVMFXRPN-UHFFFAOYAM
  • [Cu]O[Cu]
  • [Cu+].[Cu+].[O-2]
Properties
Cu2O
Molar mass 143.09 g/mol
Appearancebrownish-red solid
Density 6.0 g/cm3
Melting point 1,232 °C (2,250 °F; 1,505 K)
Boiling point 1,800 °C (3,270 °F; 2,070 K)
Insoluble
Solubility in acidSoluble
Band gap 2.137  eV
−20×10−6 cm3/mol
Structure
cubic
Pn3m, #224
a = 4.2696
Thermochemistry
Std molar
entropy (S⦵298)
93 J·mol−1·K−1
−170 kJ·mol−1
Hazards
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
Danger
H302, H318, H332, H410
P273, P305+P351+P338 [1]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
0
1
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m3 (as Cu) [2]
REL (Recommended)
TWA 1 mg/m3 (as Cu) [2]
IDLH (Immediate danger)
TWA 100 mg/m3 (as Cu) [2]
Safety data sheet (SDS) SIRI.org
Related compounds
Other anions
Copper(I) sulfide
Copper(II) sulfide
Copper(I) selenide
Other cations
Copper(II) oxide
Silver(I) oxide
Nickel(II) oxide
Zinc oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Copper(I) oxide or cuprous oxide is the inorganic compound with the formula Cu2O. It is one of the principal oxides of copper, the other being copper(II) oxide or cupric oxide (CuO). Cuprous oxide is a red-coloured solid and is a component of some antifouling paints. The compound can appear either yellow or red, depending on the size of the particles. [3] Copper(I) oxide is found as the reddish mineral cuprite.

Contents

Preparation

Copper(I) oxide may be produced by several methods. [4] Most straightforwardly, it arises via the oxidation of copper metal:

4 Cu + O2 → 2 Cu2O

Additives such as water and acids affect the rate of this process as well as the further oxidation to copper(II) oxides. It is also produced commercially by reduction of copper(II) solutions with sulfur dioxide.

Alternatively, it may be prepared via the reduction of Copper (II) Hydroxide with hydrogen peroxide during "a complex mechanism with the participation of three different reaction pathways is involved." with the final reducing reaction being: [5]

2 CuOOH+ → 2Cu(I) + H2O2 + O2

2Cu 2+ + OH- + H2O2 → 2Cu + + O2 + H2O [6]

Reactions

Aqueous cuprous chloride solutions react with base to give the same material. In all cases, the color is highly sensitive to the procedural details.

Pourbaix diagram for copper in uncomplexed media (anions other than OH not considered). Ion concentration 0.001 mol/kg water. Temperature 25 degC. Cu-pourbaix-diagram.svg
Pourbaix diagram for copper in uncomplexed media (anions other than OH not considered). Ion concentration 0.001 mol/kg water. Temperature 25 °C.

Formation of copper(I) oxide is the basis of the Fehling's test and Benedict's test for reducing sugars. These sugars reduce an alkaline solution of a copper(II) salt, giving a bright red precipitate of Cu2O.

It forms on silver-plated copper parts exposed to moisture when the silver layer is porous or damaged. This kind of corrosion is known as red plague.

Little evidence exists for copper(I) hydroxide CuOH, which is expected to rapidly undergo dehydration. A similar situation applies to the hydroxides of gold(I) and silver(I).

Properties

The solid is diamagnetic. In terms of their coordination spheres, copper centres are 2-coordinated and the oxides are tetrahedral. The structure thus resembles in some sense the main polymorphs of SiO2, but cuprous oxide's lattices interpenetrate.

Copper(I) oxide dissolves in concentrated ammonia solution to form the colourless complex [Cu(NH3)2]+, which is easily oxidized in air to the blue [Cu(NH3)4(H2O)2]2+. It dissolves in hydrochloric acid to give solutions of CuCl−
2. Dilute sulfuric acid and nitric acid produce copper(II) sulfate and copper(II) nitrate, respectively. [7]

Cu2O degrades to copper(II) oxide in moist air.

Structure

Cu2O crystallizes in a cubic structure with a lattice constant al = 4.2696 Å. The copper atoms arrange in a fcc sublattice, the oxygen atoms in a bcc sublattice. One sublattice is shifted by a quarter of the body diagonal. The space group is Pn3m, which includes the point group with full octahedral symmetry.

Semiconducting properties

In the history of semiconductor physics, Cu2O is one of the most studied materials, and many experimental semiconductor applications have been demonstrated first in this material:

The lowest excitons in Cu2O are extremely long lived; absorption lineshapes have been demonstrated with neV linewidths, which is the narrowest bulk exciton resonance ever observed. [11] The associated quadrupole polaritons have low group velocity approaching the speed of sound. Thus, light moves almost as slowly as sound in this medium, which results in high polariton densities. Another unusual feature of the ground state excitons is that all primary scattering mechanisms are known quantitatively. [12] Cu2O was the first substance where an entirely parameter-free model of absorption linewidth broadening by temperature could be established, allowing the corresponding absorption coefficient to be deduced. It can be shown using Cu2O that the Kramers–Kronig relations do not apply to polaritons. [13]

Applications

Cuprous oxide is commonly used as a pigment, a fungicide, and an antifouling agent for marine paints. Rectifier diodes based on this material have been used industrially as early as 1924, long before silicon became the standard. Copper(I) oxide is also responsible for the pink color in a positive Benedict's test.

In December 2021, Toshiba announced the creation of a transparent cuprous oxide (Cu2O) thin-film solar cell. The cell achieved an 8.4% energy conversion efficiency, the highest efficiency ever reported for any cell of this type as of 2021. The cells could be used for high-altitude platform station applications and electric vehicles. [14]

Similar compounds

An example of natural copper(I,II) oxide is the mineral paramelaconite, Cu4O3 or CuI
2CuII
2O3. [15] [16]

See also

Related Research Articles

<span class="mw-page-title-main">Exciton</span> Quasiparticle which is a bound state of an electron and an electron hole

An electron and an electron hole that are attracted to each other by the Coulomb force can form a bound state called an exciton. It is an electrically neutral quasiparticle that exists mainly in condensed matter, including insulators, semiconductors, some metals, but also in certain atoms, molecules and liquids. The exciton is regarded as an elementary excitation that can transport energy without transporting net electric charge.

Benedict's reagent is a chemical reagent and complex mixture of sodium carbonate, sodium citrate, and copper(II) sulfate pentahydrate. It is often used in place of Fehling's solution to detect the presence of reducing sugars. The presence of other reducing substances also gives a positive result. Such tests that use this reagent are called the Benedict's tests. A positive test with Benedict's reagent is shown by a color change from clear blue to brick-red with a precipitate.

<span class="mw-page-title-main">Basic copper carbonate</span> Chemical compound

Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It is an ionic compound consisting of the ions copper(II) Cu2+
, carbonate CO2−
3, and hydroxide OH−
.

<span class="mw-page-title-main">Copper oxide</span> Index of chemical compounds with the same name

Copper oxide is any of several binary compounds composed of the elements copper and oxygen. Two oxides are well known, Cu2O and CuO, corresponding to the minerals cuprite and tenorite, respectively. Paramelaconite (Cu4O3) is less well characterized.

<span class="mw-page-title-main">Copper(II) oxide</span> Chemical compound – an oxide of copper with formula CuO

Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds.

<span class="mw-page-title-main">Copper(I) chloride</span> Chemical compound

Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride (CuCl2).

<span class="mw-page-title-main">Copper(II) chloride</span> Chemical compound

Copper(II) chloride, also known as cupric chloride, is an inorganic compound with the chemical formula CuCl2. The monoclinic yellowish-brown anhydrous form slowly absorbs moisture to form the orthorhombic blue-green dihydrate CuCl2·2H2O, with two water molecules of hydration. It is industrially produced for use as a co-catalyst in the Wacker process.

<span class="mw-page-title-main">Tin(II) oxide</span> Chemical compound, stannous oxide (SnO)

Tin(II) oxide is a compound with the formula SnO. It is composed of tin and oxygen where tin has the oxidation state of +2. There are two forms, a stable blue-black form and a metastable red form.

<span class="mw-page-title-main">Copper(I) iodide</span> Chemical compound

Copper(I) iodide is the inorganic compound with the formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding.

<span class="mw-page-title-main">Copper(II) hydroxide</span> Hydroxide of copper

Copper(II) hydroxide is the hydroxide of copper with the chemical formula of Cu(OH)2. It is a pale greenish blue or bluish green solid. Some forms of copper(II) hydroxide are sold as "stabilized" copper(II) hydroxide, although they likely consist of a mixture of copper(II) carbonate and hydroxide. Cupric hydroxide is a strong base, although its low solubility in water makes this hard to observe directly.

<span class="mw-page-title-main">Copper(I) sulfide</span> Chemical compound

Copper(I) sulfide is a copper sulfide, a chemical compound of copper and sulfur. It has the chemical compound Cu2S. It is found in nature as the mineral chalcocite. It has a narrow range of stoichiometry ranging from Cu1.997S to Cu2.000S. Samples are typically black.

Copper(I) hydroxide is the hydroxide of the metal copper with the chemical formula of CuOH. It is a mild, highly unstable alkali. The color of pure CuOH is yellow or orange-yellow, but it usually appears rather dark red because of impurities. It is extremely easily oxidized even at room temperature. It is useful for some industrial processes and in preventing condensation of formaldehyde. It is also an important reactant and intermediate for several important products including Cu2O3 and Cu(OH)2. Additionally, it can act as a catalyst in the synthesis pyrimidopyrrolidone derivatives.

<span class="mw-page-title-main">Delafossite</span> Copper iron oxide mineral

Delafossite is a copper iron oxide mineral with formula CuFeO2 or Cu1+Fe3+O2. It is a member of the delafossite mineral group, which has the general formula ABO2, a group characterized by sheets of linearly coordinated A cations stacked between edge-shared octahedral layers (BO6). Delafossite, along with other minerals of the ABO2 group, is known for its wide range of electrical properties, its conductivity varying from insulating to metallic. Delafossite is usually a secondary mineral that crystallizes in association with oxidized copper and rarely occurs as a primary mineral.

Copper(I) sulfate, also known as cuprous sulfate, is an inorganic compound with the chemical formula Cu2SO4. It is a white solid, in contrast to copper(II) sulfate, which is blue in hydrous form. Compared to the commonly available reagent, copper(II) sulfate, copper(I) sulfate is unstable and not readily available.

<span class="mw-page-title-main">Paramelaconite</span> Oxide mineral

Paramelaconite is a rare, black-colored copper(I,II) oxide mineral with formula CuI
2CuII
2O3 (or Cu4O3). It was discovered in the Copper Queen Mine in Bisbee, Arizona, about 1890. It was described in 1892 and more fully in 1941. Its name is derived from the Greek word for "near" and the similar mineral melaconite, now known as tenorite.

Bose–Einstein condensation can occur in quasiparticles, particles that are effective descriptions of collective excitations in materials. Some have integer spins and can be expected to obey Bose–Einstein statistics like traditional particles. Conditions for condensation of various quasiparticles have been predicted and observed. The topic continues to be an active field of study.

Copper peroxide is a hypothetical inorganic compound with the chemical formula CuO2. The 1:2 ratio of copper and oxygen would be consistent with copper in its common +2 oxidation state and a peroxide group. Although samples of this composition have not been isolated, CuO2 has attracted interest from computational perspective. One highly cited analysis concludes that gaseous CuO2 is a superoxide, with copper in a +1 oxidation state: Cu+O−2.

<span class="mw-page-title-main">Copper(I) thiocyanate</span> Chemical compound

Copper(I) thiocyanate is a coordination polymer with formula CuSCN. It is an air-stable, white solid used as a precursor for the preparation of other thiocyanate salts.

<span class="mw-page-title-main">Chevreul's salt</span> Chemical compound

Chevreul's salt (copper(I,II) sulfite dihydrate, Cu2SO3•CuSO3•2H2O or Cu3(SO3)2•2H2O), is a copper salt which was prepared for the first time by a French chemist Michel Eugène Chevreul in 1812. Its unusual property is that it contains copper in both of its common oxidation states, making it a mixed-valence complex. It is insoluble in water and stable in air. What was known as Rogojski's salt is a mixture of Chevreul's salt and metallic copper.

<span class="mw-page-title-main">Copper compounds</span> Chemical compounds containing copper

Copper forms a rich variety of compounds, usually with oxidation states +1 and +2, which are often called cuprous and cupric, respectively. Copper compounds, whether organic complexes or organometallics, promote or catalyse numerous chemical and biological processes.

References

  1. ↑ https://www.nwmissouri.edu/naturalsciences/sds/c/Copper%20I%20oxide.pdf [ dead link ]
  2. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
  4. ↑ H. Wayne Richardson "Copper Compounds in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a07_567
  5. ↑ Perez-Benito, Joaquin F. (2004-03-01). "Reaction pathways in the decomposition of hydrogen peroxide catalyzed by copper(II)". Journal of Inorganic Biochemistry. 98 (3): 430–438. doi:10.1016/j.jinorgbio.2003.10.025. ISSN   0162-0134. PMID   14987843.
  6. ↑ Yener, Ersin (September 2017). "Improvement of Stability of Hydrogen Peroxide using Ethylene Glycol".
  7. ↑ D. Nicholls, Complexes and First-Row Transition Elements, Macmillan Press, London, 1973.
  8. ↑ L. O. Grondahl, Unidirectional current carrying device, Patent, 1927
  9. ↑ Hanke, L.; Fröhlich, D.; Ivanov, A. L.; Littlewood, P. B.; Stolz, H. (1999-11-22). "LA Phonoritons in Cu2O". Physical Review Letters. 83 (21): 4365–4368. Bibcode:1999PhRvL..83.4365H. doi:10.1103/PhysRevLett.83.4365.
  10. ↑ L. Brillouin: Wave Propagation and Group Velocity, Academic Press, New York City, 1960 ISBN   9781483276014.
  11. ↑ Brandt, Jan; Fröhlich, Dietmar; Sandfort, Christian; Bayer, Manfred; Stolz, Heinrich; Naka, Nobuko (2007-11-19). "Ultranarrow Optical Absorption and Two-Phonon Excitation Spectroscopy of Cu2O Paraexcitons in a High Magnetic Field". Physical Review Letters. 99 (21). American Physical Society (APS): 217403. Bibcode:2007PhRvL..99u7403B. doi:10.1103/physrevlett.99.217403. ISSN   0031-9007. PMID   18233254.
  12. ↑ J. P. Wolfe and A. Mysyrowicz: Excitonic Matter, Scientific American 250 (1984), No. 3, 98.
  13. ↑ Hopfield, J. J. (1958). "Theory of the Contribution of Excitons to the Complex Dielectric Constant of Crystals". Physical Review. 112 (5): 1555–1567. Bibcode:1958PhRv..112.1555H. doi:10.1103/PhysRev.112.1555. ISSN   0031-899X.
  14. ↑ Bellini, Emiliano (2021-12-22). "Toshiba claims 8.4% efficiency for transparent cuprous oxide solar cell". pv magazine. Retrieved 2021-12-22.
  15. ↑ "Paramelaconite".
  16. ↑ "List of Minerals". 21 March 2011.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.