Editing Cadmium (section)

==Applications==
Cadmium is a common component of electric batteries, [[cadmium pigments|pigments]],<ref name="colors" /> coatings,<ref name="fff" /> and electroplating.<ref name="HgCdPb" />

===Batteries===
[[File:NiCd various.jpg|thumb|Ni–Cd batteries]]
In 2009, 86% of cadmium was used in [[Battery (electricity)|batteries]], predominantly in [[rechargeable battery|rechargeable]] [[nickel–cadmium battery|nickel–cadmium batteries]]. Nickel–cadmium cells have a nominal cell potential of 1.2&nbsp;[[Volt|V]]. The cell consists of a positive [[nickel hydroxide]] [[electrode]] and a negative cadmium electrode plate separated by an [[alkaline]] [[electrolyte]] ([[potassium hydroxide]]).<ref>{{cite book |last= Krishnamurthy |first= N. |date= 2 July 2013 |title= Engineering Chemistry, 2nd edition |location= New York |publisher= PHI Learning Private Limited |pages= 82–83 |isbn= 978-81-203-3666-7 }}</ref> The European Union put a limit on cadmium in electronics in 2004 of 0.01%,<ref>{{CELEX|32011L0065|text=Directive 2011/65/EU of the European Parliament and of the Council of 8 June 2011 on the restriction of the use of certain hazardous substances in electrical and electronic equipment}}</ref> with some exceptions, and in 2006 reduced the limit on cadmium content to 0.002%.<ref name="EC_Directive">{{CELEX|32006L0066|text=Directive 2006/66/EC of the European Parliament and of the Council of 6 September 2006 on batteries and accumulators and waste batteries and accumulators and repealing Directive 91/157/EEC}}</ref> Another type of battery based on cadmium is the [[silver–cadmium battery]].

===Electroplating===
[[File:CdSeqdots.jpg|thumb|A photograph and representative spectrum of [[photoluminescence]] from colloidal CdSe [[quantum dot]]s]]
Cadmium [[electroplating]], consuming 6% of the global production, is used in the aircraft industry to reduce [[corrosion]] of steel components.<ref name="HgCdPb">{{cite book|url = https://books.google.com/books?id=9yzN-QGag_8C|title = Mercury, Cadmium, Lead: Handbook for Sustainable Heavy Metals Policy and Regulation|first1 = Michael J.|last1 = Scoullos|last2= Vonkeman|first2=Gerrit H.|last3 = Thornton|first3=Iain|last4 = Makuch |first4=Zen| publisher = Springer|date = 2001|isbn = 978-1-4020-0224-3}}</ref> This coating is passivated by [[Chromate and dichromate|chromate]] salts.<ref name="fff">{{cite web |url=http://ftp.rta.nato.int/public//PubFulltext/RTO/MP/RTO-MP-025///MP-025-15.pdf |title=Advances to Protective Coatings and their Application to Ageing Aircraft |last1=Smith|first1=C.J.E.|last2=Higgs|first2=M.S.|last3=Baldwin|first3=K.R. |date=20 April 1999 |publisher=RTO MP-25 |access-date=29 May 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110517202722/http://ftp.rta.nato.int/public/ |archive-date=17 May 2011}}</ref> A limitation of cadmium plating is [[hydrogen embrittlement]] of high-strength steels from the electroplating process. Therefore, steel parts heat-treated to tensile strength above 1300 MPa (200 ksi) should be coated by an alternative method (such as special low-embrittlement cadmium electroplating processes or physical vapor deposition).

Titanium embrittlement from cadmium-plated tool residues resulted in banishment of those tools (and the implementation of routine tool testing to detect cadmium contamination) in the A-12/SR-71, U-2, and subsequent aircraft programs that use titanium.<ref>{{cite web|url = https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/a-12/breaking-through-technological-barriers.html|archive-url = https://web.archive.org/web/20071009211528/https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/a-12/breaking-through-technological-barriers.html|url-status = dead|archive-date = 9 October 2007|title = CIA – Breaking Through Technological Barriers – Finding The Right Metal (A-12 program)|date=1 October 2007}}</ref>

===Nuclear technology===
Cadmium is used in the [[control rod]]s of nuclear reactors, acting as a very effective [[neutron poison]] to control [[neutron flux]] in [[nuclear fission]].<ref name="HgCdPb" /> When cadmium rods are inserted in the core of a nuclear reactor, cadmium absorbs neutrons, preventing them from creating additional fission events, thus controlling the amount of reactivity. The [[pressurized water reactor]] designed by [[Westinghouse Electric Company]] uses an alloy consisting of 80% silver, 15% indium, and 5% cadmium.<ref name="HgCdPb" />

===Televisions===
[[Quantum dot display|QLED TVs]] have been starting to include cadmium in construction. Some companies have been looking to reduce the environmental impact of human exposure and pollution of the material in televisions during production.<ref>{{Cite news|url=https://theconversation.com/are-quantum-dot-tvs-and-their-toxic-ingredients-actually-better-for-the-environment-35953|title=Are quantum dot TVs – and their toxic ingredients – actually better for the environment?|last=Maynard|first=Andrew|work=The Conversation|access-date=2017-07-23|language=en}}</ref>

===Anticancer drugs===
Complexes based on cadmium and other heavy metals have potential for the treatment of cancer, but their use is often limited due to toxic side effects.<ref>{{Cite journal|last1=Abyar|first1=Selda|last2=Khandar|first2=Ali Akbar|last3=Salehi|first3=Roya|last4=Abolfazl Hosseini-Yazdi|first4=Seyed|last5=Alizadeh|first5=Effat|last6=Mahkam|first6=Mehrdad|last7=Jamalpoor|first7=Amer|last8=White|first8=Jonathan M.|last9=Shojaei|first9=Motahhareh|last10=Aizpurua-Olaizola|first10=O.|last11=Masereeuw|first11=Rosalinde|display-authors=3|date=December 2019|title=In vitro nephrotoxicity and anticancer potency of newly synthesized cadmium complexes|journal=Scientific Reports|language=en|volume=9|issue=1|pages=14686|doi=10.1038/s41598-019-51109-9|issn=2045-2322|pmc=6789105|pmid=31604983|bibcode=2019NatSR...914686A}}</ref>

===Compounds===
[[File:Tyne and Wear Metro train 4001 at Pelaw 01.jpg|thumb|Train painted with [[Cadmium pigments|cadmium orange]]]]
[[Cadmium oxide]] was used in black and white television phosphors and in the blue and green phosphors of color television cathode ray tubes.<ref>{{cite journal|journal = [[Environmental Science & Technology]] |volume = 36|issue = 1|pages = 69–75|date = 2002|doi = 10.1021/es010517q|title = Recycling of Scrap Cathode Ray Tubes|first1 = Ching-Hwa|last1 = Lee|pmid = 11811492|last2 = Hsi|first2 = C. S.|bibcode = 2002EnST...36...69L }}</ref> [[Cadmium sulfide]] (CdS) is used as a photoconductive surface coating for photocopier drums.<ref>{{cite book|chapter-url = https://books.google.com/books?id=8Yt6GzSEZRkC&pg=PR18|title =Electronic materials: from silicon to organics|first1= L. S.|last1 = Miller|first2=J. B. |last2= Mullin|publisher = Springer|date = 1991|isbn = 978-0-306-43655-0|page = 273|chapter = Crystalline Cadmium Sulfide}}</ref>

[[File:Cadmium sulfide.jpg|thumb|left|upright=0.5|Cadmium sulfide]]
Various cadmium salts are used in paint pigments, with CdS as a [[Cadmium pigments|yellow pigment]] being the most common. [[Cadmium selenide]] is a red pigment, commonly called ''cadmium red''. To painters who work with the pigment, cadmium provides the most brilliant and durable yellows, oranges, and reds&nbsp;– so much so that during production, these colors are significantly toned down before they are ground with oils and binders or blended into [[watercolor]]s, [[gouache]]s, [[Acrylic paint|acrylics]], and other paint and pigment formulations. Because these pigments are potentially toxic, for safety users normally use a [[barrier cream]] on the hands to prevent absorption through the skin<ref name="colors">{{cite book|chapter = Cadmium Pigments|chapter-url = https://books.google.com/books?id=_OrB0ew_HgAC&pg=PA121|pages = 121–123|isbn = 978-3-527-30363-2|publisher = Wiley-VCH|date = 2005|title = Industrial inorganic pigments|first1 = Gunter|last1 = Buxbaum|first2 = Gerhard|last2 = Pfaff}}{{Dead link|date=March 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> even though the amount of cadmium absorbed into the body through the skin is reported to be less than 1%.<ref name = "ATSDR" />

In [[polyvinyl chloride|PVC]], cadmium was used as heat, light, and weathering stabilizers.<ref name="HgCdPb" /><ref>{{cite book|chapter-url = https://books.google.com/books?id=YUkJNI9QYsUC&pg=PA149|page = 149|first = Thomas C.|last = Jennings|isbn = 978-1-56990-379-7| publisher = Hanser Verlag|date = 2005|title = PVC handbook|chapter = Cadmium Environmental Concerns}}</ref> Currently, cadmium stabilizers have been completely replaced with barium-zinc, calcium-zinc and organo-tin stabilizers. Cadmium is used in many kinds of [[solder]] and bearing alloys, because it has a low [[coefficient of friction]] and fatigue resistance.<ref name="HgCdPb" /> It is also found in some of the lowest-melting [[alloy]]s, such as [[Wood's metal]].<ref>{{cite book|first1= George Stuart|last1= Brady|first2= George S.|last2= Brady|first3= Henry R.|last3= Clauser|first4 = John A.|last4 = Vaccari|isbn = 978-0-07-136076-0|url = https://books.google.com/books?id=vIhvSQLhhMEC&pg=PA425|title = Materials handbook: an encyclopedia for managers, technical professionals, purchasing and production managers, technicians, and supervisors|publisher = McGraw-Hill Professional|date = 2002| page = 425}}</ref>

===Semiconductors===
Cadmium is an element in some [[semiconductor]] materials. Cadmium sulfide, cadmium selenide, and [[cadmium telluride]] are used in some [[photodetectors]] and [[solar cell]]s. [[HgCdTe]] detectors are sensitive to mid-[[infrared]] light<ref name="HgCdPb" /> and used in some motion detectors.

===Laboratory uses===
[[File:HeCd laser.jpg|thumb|Violet light from a [[helium]] cadmium metal vapor [[laser]]. The highly [[monochromatic]] color arises from the 441.563 nm transition [[spectral line|line]] of cadmium.]]
Helium–cadmium lasers are a common source of blue or ultraviolet laser light. Lasers at wavelengths of 325, 354 and 442&nbsp;nm are made using this [[gain medium]]; some models can switch between these wavelengths. They are notably used in [[fluorescence microscopy]] as well as various laboratory uses requiring laser light at these wavelengths.<ref>{{cite web| url = http://www.olympusfluoview.com/java/hecdlasers/index.html| title = Helium–Cadmium Lasers| publisher = Olympus| access-date = 14 May 2011| url-status = dead| archive-url = https://web.archive.org/web/20110715000100/http://www.olympusfluoview.com/java/hecdlasers/index.html| archive-date = 15 July 2011}}</ref><ref>{{cite book|chapter-url = https://books.google.com/books?id=JxASQpi0LXoC&pg=PA488| chapter = Helium–cadmium Laser|title = Lasers: Principles, Types and Applications|isbn = 978-81-224-1492-9|author1 = Nambiar, K.R|date = 2006| publisher = New Age International}}</ref>

Cadmium selenide [[quantum dot]]s emit bright [[luminescence]] under UV excitation (He–Cd laser, for example). The color of this luminescence can be green, yellow or red depending on the particle size. Colloidal solutions of those particles are used for imaging of biological tissues and solutions with a [[fluorescence microscope]].<ref>{{cite news|url=http://mix.msfc.nasa.gov/abstracts.php?p=3906|publisher=NASA|title=Cadmium Selenium Testing for Microbial Contaminants|date=10 June 2003|access-date=20 November 2009|archive-url=https://web.archive.org/web/20110725023512/http://mix.msfc.nasa.gov/abstracts.php?p=3906|archive-date=25 July 2011|url-status=dead}}</ref>

In molecular biology, cadmium is used to block [[Voltage-gated calcium channel|voltage-dependent calcium channels]] from fluxing calcium ions, as well as in [[Hypoxia (medical)|hypoxia]] research to stimulate [[proteasome]]-dependent degradation of [[Hypoxia-inducible factors|Hif-1α]].<ref>{{cite journal|journal = European Journal of Biochemistry|volume = 267|issue = 13|pages = 4198–4204|date = 2000|doi = 10.1046/j.1432-1327.2000.01453.x|title = Cadmium blocks hypoxia-inducible factor (HIF)-1-mediated response to hypoxia by stimulating the proteasome-dependent degradation of HIF-1alpha|first1 = Chun Y. S.|last1 = Park J. W.|pmid = 10866824|last2 = Choi|first2 = E.|last3 = Kim|first3 = G. T.|last4 = Choi|first4 = H.|last5 = Kim|first5 = C. H.|last6 = Lee|first6 = M. J.|last7 = Kim|first7 = M. S.|last8 = Park|first8 = J. W.|doi-access = free}}</ref>

Cadmium-selective sensors based on the [[fluorophore]] [[BODIPY]] have been developed for imaging and sensing of cadmium in cells.<ref>{{cite book
|last1=Taki
|first1=Masayasu
|title=Cadmium: From Toxicity to Essentiality
|chapter=Imaging and Sensing of Cadmium in Cells
|editor=Astrid Sigel
|editor2=Helmut Sigel
|editor3=Roland K. O. Sigel
|series=Metal Ions in Life Sciences
|volume=11
|date=2013
|publisher=Springer
|pages=99–115
|doi=10.1007/978-94-007-5179-8_5|pmid=23430772
|isbn=978-94-007-5178-1
}}
</ref> One powerful method for monitoring cadmium in aqueous environments involves [[electrochemistry]]. By employing a [[self-assembled monolayer]] one can obtain a cadmium selective electrode with a [[Parts-per notation|ppt]]-level sensitivity.<ref>{{Cite journal|last1=Noyhouzer|first1=Tomer|last2=Mandler|first2=Daniel|date=2011-01-17|title=Determination of low levels of cadmium ions by the under potential deposition on a self-assembled monolayer on gold electrode|journal=Analytica Chimica Acta|volume=684|issue=1–2|pages=1–7|doi=10.1016/j.aca.2010.10.021|pmid=21167979|bibcode=2011AcAC..684....1N }}</ref>