The Copper sulphides Describe a family of chemical and mineral compounds with the formula Cu X S Y . These compounds comprise economically important minerals and synthetic materials.
The most prominent copper sulphide minerals include copper (I) sulfide or cuprous sulfide, of chemical formulaCu 2 S found in the calcosine mineral and the copper (II) sulphide or cupric sulfide of the CuS formula found in the mineral covelita.
Figure 1: Structure of the copper sulfide (I) (left) and copper (II) sulfide (right)
Calcosine has been mined for centuries and is one of the most profitable copper minerals. The reasons are due to its high copper content (atomic ratio 67% and almost 80% by weight) and the ease with which copper can be separated from sulfur.
However, it is not the main mineral of copper due to its scarcity. Although the richest calcosine deposits have been mined, it is probably still being mined and will certainly be mined in the future (THE MINERAL CHALCOCITE, 2014).
Figure 2: Calcosine mineral.
Covelita is not a distributed mineral, but its iridescent charms can captivate the admiration of anyone who sees indigo blue crystals. Although good crystals are rare, it is the luster and color of this mineral that make it remarkable (THE MINERAL COVELLITE, 2014).
Figure 3: Covelite mineral.
In the mining industry, bornite or chalcopyrite minerals, which consist of mixed sulphides of copper and iron, are often referred to as"copper sulphides".
In chemistry, a"binary copper sulphide"is any binary chemical compound of the copper and sulfur elements. Whatever their source, copper sulphides vary widely in composition with 0.5 ≤ Cu / S ≤ 2, including numerous non-stoichiometric compounds.
Physical and chemical properties of copper sulphides
Copper (I) and (II) sulfide have similar appearances, both being dark, gray or black crystals.
Figure 4: appearance of copper (II) sulfide.
These compounds can be differentiated by their crystalline structure. Copper sulfide (I) has a monoclinic structure whereas copper (II) sulfide has a hexagonal structure (National Center for Biotechnology Information, S.F.).
They have a molecular weight of 159.16 g / mol and 95.611 g / mol and a density of 5.6 g / ml and 4.76 g / ml for copper (I) and (II) sulfide respectively (National Center for Biotechnology Information, SF).
Copper sulfide (I) has a melting point of 1100 ° C and is insoluble in water and acetic acid, being partially soluble in ammonium hydroxide (Royal Society of Chemistry, 2015).
Copper (II) sulfide has a melting point of 220 ° C where it decomposes, is insoluble in water, hydrochloric and sulfuric acid and is soluble in nitric acid, ammonium hydroxide and potassium cyanide (Royal Society of Chemistry, 2015 ).
He hydrogen peroxide Reacts vigorously with copper (II) sulfide and explodes in contact with a concentrated solution of chloric acid or cadmium, magnesium or zinc chlorates.
Reactivity and hazards
Copper (I) and (II) sulphides are not classified as hazardous, however they may be toxic if swallowed due to the production of hydrogen sulphide. Symptoms include vomiting, gastric pain and dizziness, may cause irritation to the skin and eyes and inhalation may cause respiratory irritation (MATERIAL SAFETY DATA SHEET Copper Sulfide, 1995).
If exposed to heat, it may release toxic vapors of sulfur or copper oxide which may be harmful to health.
In case of contact with eyes, they should be rinsed immediately with sufficient amount of water for 15 minutes, raising the lower and upper eyelids occasionally.
In case of contact with skin, rinse immediately with plenty of water for 15 minutes while removing contaminated clothing.
If swallowed, call a poison control center immediately. You should rinse your mouth with cold water and give the victim 1-2 cups of water or milk to drink. Immediately induce vomiting.
In case of inhalation, the victim should be taken to a cool place. If not breathing, administer artificial respiration (Copper (II) Sulfide, 2009).
Applications
Copper sulfide (I) is used as semiconductor and in photographic applications (americanelements, 1998-2017). Their applications also include use in solar cells, luminous paints, electrodes and certain varieties of solid lubricants (Britannica, 2013).
On the other hand, copper (II) sulfide finds applications in solar cells, superionic conductors, photodetectors, electroconductive electrodes, photothermal conversion devices, microwave protective coating, active radio wave absorbers, gas sensors and radiation polarizers Infrared (azom, 2013).
Also the copper (II) sulfide (covelita) is used in the study of nanoparticles:
- With different manufacturing procedures (solvothermic routes, aerosol methods, solution methods and thermolysis)
- And applications (photocatalytic degradation, cancer cell ablation, electrode material in lithium-ion and gas-cell batteries, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, bio- Electrochemical detection, enhanced PEC characteristics of pre-cut CuS film electrodes) (Umair Shamraiz, 2016).
In the work of Geng Ku (2012) the use of nanoparticles of semiconductor copper sulphide (CuS NPs) was demonstrated for the visualization of photoacoustic tomographies with an Nd: YAG laser at a wavelength of 1064 nm.
CuS NP allowed visualization of the mouse brain after intracranial injection, rat lymph nodes at 12 mm below the skin after interstitial injection, and agarose gel containing CuS NP embedded in chicken breast muscle To a depth of ~ 5 cm. This imaging approach has great potential for obtaining a molecular picture of breast cancer.
References
- (1998-2017). Copper (I) Sulfide. Retrieved from americanelements.com.
- (2013, April 19). Copper Sulfide (CuS) Semiconductors. Retrieved from azom.com.
- Britannica, T. E. (2013, Aug. 23). Copper (Cu). Retrieved from britannica.com.
- Copper (II) Sulfide. (2009, January 23). Retrieved from onboces.org.
- Geng Ku, M. Z. (2012). Copper Sulfide Nanoparticles As a New Class of Photoacoustic Contrast Agent for Deep Tissue Imaging at 1064 nm. ACS Nano 6 (8), 7489-7496.
- MATERIAL SAFETY DATA SHEET Copper Sulfide. (1995, November). Retrieved from onboces.org.
- National Center for Biotechnology Information. (S.F.). PubChem Compound Database; CID = 14831. Retrieved from pubchem.ncbi.nlm.nih.gov.
- National Center for Biotechnology Information. (S.F.). PubChem Compound Database; CID = 62755. Retrieved from pubchem.ncbi.nlm.nih.gov.
- Royal Society of Chemistry. (2015). Copper (II) sulfide. Retrieved from chemspider.com.
- Royal Society of Chemistry. (2015). Dicopper (1+) sulfide. Retrieved from chemspider.com.
- THE MINERAL CHALCOCITE. (2014). Retrieved from galleries.com.
- THE MINERAL COVELLITE. (2014). Retrieved from galleries.com.
- Umair Shamraiz, R.A. (2016). Fabrication and applications of copper sulfide (CuS) nanostructures. Journal of Solid State Chemistry Volume 238, 25-40.