Cadmium sulfide
{{chembox
| Watchedfields = changed
| verifiedrevid = 476999857
| Name = Cadmium sulfide
| ImageFileL1 = Hawleyite-3D-balls.png
| ImageNameL1 = 3D model of the structure of hawleyite
| ImageFileR1 = Greenockite-3D-balls.png
| ImageNameR1 = 3D model of the structure of greenockite
| ImageFile2 = Cadmium sulfide.jpg
| OtherNames = cadmium(II) sulfide
greenockite
hawleyite
cadmium yellow
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 7969586
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 057EZR4Z7Q
| ChEBI = 50833
| Gmelin = 13655
| InChI = 1/Cd.S/q+2;-2
| SMILES = [S-2].[Cd+2]
| SMILES_Comment = monomer
| SMILES1 = [SH+2]12[CdH2-2] [SH+2]3[CdH2-2] [SH+2]([CdH-2]14)[CdH-2]1[S+2]5([CdH-2]38)[Cd-2]26[SH+2]2[CdH-2]([S+2]4)[SH+2]1[CdH2-2] [SH+2]3[CdH-2]2[S+2] [CdH-2]([SH+2]6[CdH-2]([SH+2])[SH+2]68)[SH+2]([CdH2-2]6)[CdH-2]35
| SMILES1_Comment = hawleyite
| SMILES2 = [CdH2-2]1[S+2]47[CdH-2]2[S+2] [CdH-2]3[S+2]8([CdH2-2] [SH+2]([CdH2-2]4)[CdH2-2]6)[CdH-2]4[S+2] [CdH-2]5[S+2]6([CdH2-2]6)[Cd-2]78[S+2]78[CdH-2]([SH+2]69)[SH+2]5[CdH2-2] [SH+2]4[CdH-2]7[SH+2]3[CdH2-2] [SH+2]2[CdH-2]8[SH+2]1[CdH2-2]9
| SMILES2_Comment = greenockite
| SMILES3 = [CdH2-2]1[SH+2]([CdH2-2]6)[CdH2-2] [SH+2]7[CdH-2]2[S+2] [Cd-2]3([S+2] [CdH-2]9[S+2]5)[S+2]18[Cd-2]45[S+2] [CdH-2]5[SH+2]6[Cd-2]78[S+2]78[CdH2-2] [SH+2]5[CdH2-2] [S+2]4([CdH2-2] [SH+2]9[CdH2-2]4)[CdH-2]7[S+2]34[CdH2-2] [SH+2]2[CdH2-2]8
| SMILES3_Comment = greenockite
| InChIKey = FRLJSGOEGLARCA-UHFFFAOYAL
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Cd.S/q+2;-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = FRLJSGOEGLARCA-UHFFFAOYSA-N
| CASNo = 1306-23-6
| CASNo_Ref = {{cascite|correct|CAS}}
| EINECS = 215-147-8
| RTECS = EV3150000
| UNNumber = 2570
| PubChem = 14783
}}
|Section2={{Chembox Properties
| Cd=1 | S=1
| Appearance = Yellow-orange to brown solid.
| Density = 4.826 g/cm3, solid.
| Solubility = insoluble{{cite book
| last = Lide
| first = David R.
| year = 1998
| title = Handbook of Chemistry and Physics
| edition = 87
| location = Boca Raton, FL
| publisher = CRC Press
| isbn = 978-0-8493-0594-8
| pages = 4–67; 1363}}
| SolubleOther = soluble in acid
very slightly soluble in ammonium hydroxide
| MeltingPtC = 1750
| MeltingPt_notes = 10 MPa
| BoilingPtC = 980
| BoilingPt_notes = (sublimation)
| BandGap = 2.42 eV
| RefractIndex = 2.529
| MagSus = −50.0·10−6 cm3/mol
}}
|Section3={{Chembox Structure
| Coordination =
| CrystalStruct = Hexagonal, Cubic
}}
|Section4={{Chembox Thermochemistry
| DeltaHf = −162 kJ·mol−1{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| publisher = Houghton Mifflin Company| year = 2009| isbn = 978-0-618-94690-7|page=A21}}
}}
|Section7={{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0404.htm ICSC 0404]
| GHSPictograms = {{GHS07}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|341|350|361|372|413}}
| PPhrases = {{P-phrases|201|202|260|264|270|273|281|301+312|308+313|314|330|405|501}}
| NFPA-H = 3
| NFPA-F = 0
| NFPA-R = 0
| NFPA-S =
| FlashPt = Non-flammable
| LD50 = 7080 mg/kg (rat, oral)
| REL = Ca{{PGCH|0087}}
| PEL = [1910.1027] TWA 0.005 mg/m3 (as Cd)
}}
|Section8={{Chembox Related
| OtherAnions = Cadmium oxide
Cadmium selenide
Cadmium telluride
| OtherCations = Zinc sulfide
Mercury sulfide
}}
}}
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow salt.Egon Wiberg, Arnold Frederick Holleman (2001) [https://books.google.com/books?id=Mtth5g59dEIC&pg=PA522 Inorganic Chemistry], Elsevier {{ISBN|0-12-352651-5}} It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium. As a compound that is easy to isolate and purify, it is the principal source of cadmium for all commercial applications. Its vivid yellow color led to its adoption as a pigment for the yellow paint "cadmium yellow" in the 1800s.
Production
Cadmium sulfide can be prepared by the precipitation from soluble cadmium(II) salts with sulfide ion. This reaction has been used for gravimetric analysis and qualitative inorganic analysis.Fred Ibbotson (2007), The Chemical Analysis of Steel-Works' Materials,Read Books, {{ISBN|1-4067-8113-4}}
The preparative route and the subsequent treatment of the product, affects the polymorphic form that is produced (i.e., cubic vs hexagonal). It has been asserted that chemical precipitation methods result in the cubic zincblende form.Paul Klocek (1991), Handbook of Infrared Optical Materials, CRC Press {{ISBN|0-8247-8468-5}}
Pigment production usually involves the precipitation of CdS, the washing of the solid precipitate to remove soluble cadmium salts followed by calcination (roasting) to convert it to the hexagonal form followed by milling to produce a powder.{{cite book| author = Hugh MacDonald Smith|title = High Performance Pigments|year = 2002|publisher = Wiley-VCH|isbn = 978-3-527-30204-8 }} When cadmium sulfide selenides are required the CdSe is co-precipitated with CdS and the cadmium sulfoselenide is created during the calcination step.
Cadmium sulfide is sometimes associated with sulfate reducing bacteria.Larry L. Barton 1995 [https://books.google.com/books?id=yu2lmzwcQ6UC Sulfate reducing bacteria], Springer, {{ISBN|0-306-44857-2}}{{cite journal|doi=10.1016/j.chembiol.2004.08.022|title=Bacterial Biosynthesis of Cadmium Sulfide Nanocrystals|pmid=15556006|year=2004|last1=Sweeney|first1=Rozamond Y.|last2=Mao|first2=Chuanbin|last3=Gao|first3=Xiaoxia|last4=Burt|first4=Justin L.|last5=Belcher|first5=Angela M.|last6=Georgiou|first6=George|last7=Iverson|first7=Brent L.|journal=Chemistry & Biology|volume=11|issue=11|pages=1553–9|doi-access=free}}
=Routes to thin films of CdS=
Special methods are used to produce films of CdS as components in some photoresistors and solar cells. In the chemical bath deposition method, thin films of CdS have been prepared using thiourea as the source of sulfide anions and an ammonium buffer solution to control pH:{{cite journal | last1 = Oladeji | first1 = I.O. | last2 = Chow | first2 = L. | year = 1997 | title = Optimization of Chemical Bath Deposited Cadmium Sulfide | journal = J. Electrochem. Soc. | volume = 144 | issue = 7| page = 7 | doi = 10.1149/1.1837815 | citeseerx = 10.1.1.563.1643 }}
:Cd2+ + H2O + (NH2)2CS + 2 NH3 → CdS + (NH2)2CO + 2 NH4+
Cadmium sulfide can be produced using metalorganic vapour phase epitaxy and MOCVD techniques by the reaction of dimethylcadmium with diethyl sulfide:{{cite journal|doi=10.1016/S0927-0248(02)00163-0|title=Thin CdS films prepared by metalorganic chemical vapor deposition|year=2003|last1=Uda|first1=H|last2=Yonezawa|first2=H|last3=Ohtsubo|first3=Y|last4=Kosaka|first4=M|last5=Sonomura|first5=H|journal=Solar Energy Materials and Solar Cells|volume=75|issue=1–2|page=219|bibcode=2003SEMSC..75..219U }}
:Cd(CH3)2 + Et2S → CdS + CH3CH3 + C4H10
Other methods to produce films of CdS include
- Sol–gel techniques{{cite journal|doi=10.1016/S0925-8388(02)00059-2|title=Nanosized semiconductor particles in glasses prepared by the sol–gel method: their optical properties and potential uses|year=2002|last1=Reisfeld|first1=R|journal=Journal of Alloys and Compounds|volume=341|issue=1–2|page=56}}
- Sputtering{{cite journal|doi=10.1016/j.tsf.2005.11.080|title=Comparative studies of the properties of CdS films deposited on different substrates by R.F. sputtering|year=2006|last1=Moon|first1=B|last2=Lee|first2=J|last3=Jung|first3=H|journal=Thin Solid Films|volume=511–512|page=299|bibcode = 2006TSF...511..299M }}
- Electrochemical deposition{{cite journal|title=Defect reduction in electrochemically deposited CdS thin films by annealing in O2 |doi=10.1016/S0927-0248(97)00136-0|year=1998|last1=Goto|first1=F|last2=Shirai|first2=Katsunori|last3=Ichimura|first3=Masaya|journal=Solar Energy Materials and Solar Cells|volume=50|issue=1–4|page=147}}
- Spraying with precursor cadmium salt, sulfur compound and dopant{{US patent|4086101}} Photovoltaic cells, J.F. Jordan, C.M. Lampkin Issue date: April 25, 1978
- Screen printing using a slurry containing dispersed CdS{{US patent|3208022}}, High performance photoresistor, Y.T. Sihvonen, issue date: September 21, 1965
Reactions
Cadmium sulfide can be dissolved in acids.{{cite journal|doi=10.1002/app.22962|title=Extraction of CdS pigment from waste polyethylene|year=2006|last1=Wanrooij|first1=P. H. P.|last2=Agarwal|first2=U. S.|last3=Meuldijk|first3=J.|last4=Kasteren|first4=J. M. N. van|last5=Lemstra|first5=P. J.|journal=Journal of Applied Polymer Science|volume=100|issue=2|page=1024}}
:CdS + 2 HCl → CdCl2 + H2S
When solutions of sulfide containing dispersed CdS particles are irradiated with light, hydrogen gas is generated:Mario Schiavello (1985) Photoelectrochemistry, Photocatalysis, and Photoreactors: Fundamentals and Developments Springer {{ISBN|90-277-1946-2}}
: H2S → H2 + S ΔfH = +9.4 kcal/mol
The proposed mechanism involves the electron/hole pairs created when incident light is absorbed by the cadmium sulfide followed by these reacting with water and sulfide:
:Production of an electron–hole pair
::CdS + hν → e− + h+
:Reaction of electron
::2e− + 2H2O → H2 + 2OH−
:Reaction of hole
::2h+ + S2− → S
Structure and physical properties
Cadmium sulfide has, like zinc sulfide, two crystal forms. The more stable hexagonal wurtzite structure (found in the mineral Greenockite) and the cubic zinc blende structure (found in the mineral Hawleyite). In both of these forms the cadmium and sulfur atoms are four coordinate.Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications {{ISBN|0-19-855370-6}} There is also a high pressure form with the NaCl rock salt structure.
Cadmium sulfide is a direct band gap semiconductor (gap 2.42 eV).D. Lincot, Gary Hodes [https://books.google.com/books?id=bpWe4TNGnBAC&pg=PA49 Chemical Solution Deposition of Semiconducting and Non-Metallic Films: Proceedings of the International Symposium] The Electrochemical Society, 2006 {{ISBN|1-56677-433-0}} The proximity of its band gap to visible light wavelengths gives it a coloured appearance.
As well as this obvious property other properties result:
- the conductivity increases when irradiated, (leading to uses as a photoresistor)
- when combined with a p-type semiconductor it forms the core component of a photovoltaic (solar) cell and a CdS/Cu2S solar cell was one of the first efficient cells to be reported (1954)Antonio Luque, Steven Hegedus, (2003), [https://books.google.com/books?id=u-bCMhl_JjQC Handbook of Photovoltaic Science and Engineering] John Wiley and Sons {{ISBN|0-471-49196-9}}{{cite journal|doi=10.1103/PhysRev.96.533|title=Photovoltaic Effect in Cadmium Sulfide|year=1954|last1=Reynolds|first1=D.|last2=Leies|first2=G.|last3=Antes|first3=L.|last4=Marburger|first4=R.|journal=Physical Review|volume=96|issue=2|page=533|bibcode = 1954PhRv...96..533R }}
- when doped with for example Cu+ ("activator") and Al3+ ("coactivator") CdS luminesces under electron beam excitation (cathodoluminescence) and is used as phosphorC. Fouassier,(1994), Luminescence in Encyclopedia of Inorganic Chemistry, John Wiley & Sons {{ISBN|0-471-93620-0}}
- both polymorphs are piezoelectric and the hexagonal is also pyroelectric{{cite journal|doi=10.1103/PhysRev.138.A1277|title=Temperature Dependence of the Pyroelectric Effect in Cadmium Sulfide|year=1965|last1=Minkus|first1=Wilfred|journal=Physical Review|volume=138|issue=4A|pages=A1277–A1287|bibcode = 1965PhRv..138.1277M }}
- electroluminescence{{cite journal|doi=10.1103/PhysRev.105.900|title=Low-Field Electroluminescence in Insulating Crystals of Cadmium Sulfide|year=1957|last1=Smith|first1=Roland|journal=Physical Review|volume=105|issue=3|page=900|bibcode = 1957PhRv..105..900S }}
- CdS crystals can act as a gain medium in solid state laser{{cite journal|doi=10.1070/QE1972v002n03ABEH004443|year=1972|last1=Akimov|first1=Yu A|title=KGP-2: An Electron-Beam-Pumped Cadmium Sulfide Laser|last2=Burov|first2=A A|last3=Drozhbin|first3=Yu A|last4=Kovalenko|first4=V A|last5=Kozlov|first5=S E|last6=Kryukova|first6=I V|last7=Rodichenko|first7=G V|last8=Stepanov|first8=B M|last9=Yakovlev|first9=V A|journal=Soviet Journal of Quantum Electronics|volume=2|issue=3|page=284|bibcode = 1972QuEle...2..284A }}{{cite journal|last1=Agarwal|first1=Ritesh|last2=Barrelet|first2=Carl J.|last3=Lieber|first3=Charles M.|title=Lasing in Single Cadmium Sulfide Nanowire Optical Cavities|journal=Nano Letters|year=2005|volume=5|issue=5|pages=917–920|doi=10.1021/nl050440u|arxiv=cond-mat/0412144v1|pmid=15884894|bibcode = 2005NanoL...5..917A |s2cid=651903 }}
- In thin-film form, CdS can be combined with other layers for use in certain types of solar cells.{{cite journal|doi=10.1016/j.tsf.2008.11.041|title=The effect of impurities on the doping and VOC of Cd Te/CDS thin film solar cells|journal=Thin Solid Films|volume=517|issue=7|pages=2365–2369|year=2009|last1=Zhao|first1=H.|last2=Farah|first2=Alvi|last3=Morel|first3=D.|last4=Ferekides|first4=C.S.|bibcode=2009TSF...517.2365Z}} CdS was also one of the first semiconductor materials to be used for thin-film transistors (TFTs).{{cite journal | doi = 10.1109/JRPROC.1962.288190 | volume=50 | title=The TFT A New Thin-Film Transistor | year=1962 | journal=Proceedings of the IRE | pages=1462–1469 | last1 = Weimer | first1 = Paul| issue=6 | s2cid=51650159 }} However interest in compound semiconductors for TFTs largely waned after the emergence of amorphous silicon technology in the late 1970s.
- Thin films of CdS can be piezoelectric and have been used as transducers which can operate at frequencies in the GHz region.
- Nanoribbons of CdS show a net cooling due annihilation of phonons, during anti-Stokes luminescence at ~510 nm. As a result, a maximum temperature drop of 40 and 15 K has been demonstrated when the nanoribbons are pumped with a 514 or 532 nm laser.{{cite journal|last1=Zhang|first1=Jun|title=Laser cooling of a semiconductor by 40 kelvin.|journal=Nature|date=24 January 2013|volume=493|issue=7433|pages=504–508|doi=10.1038/nature11721|pmid=23344360|bibcode=2013Natur.493..504Z|s2cid=4426843 }}
Applications
=Pigment=
CdS is used as pigment in plastics, showing good thermal stability, light and weather fastness, chemical resistance and high opacity. As a pigment, CdS is known as cadmium yellow (CI pigment yellow 37).R. M. Christie 2001 [https://books.google.com/books?id=IIC3sYWh_NUC&pg=PA155 Colour Chemistry], p. 155 Royal Society of Chemistry {{ISBN|0-85404-573-2}} About 2000 tons are produced annually as of 1982, representing about 25% of the cadmium processed commercially.Karl-Heinz Schulte-Schrepping, Magnus Piscator "Cadmium and Cadmium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2007 Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a04_499}}.
=Historical use in art=
The general commercial availability of cadmium sulfide from the 1840s led to its adoption by artists, notably Van Gogh, Monet (in his London series and other works) and Matisse (Bathers by a River 1916–1919).Sidney Perkowitz, 1998, [https://books.google.com/books?id=ROHJnk2JOfIC Empire of Light: A History of Discovery in Science and Art] Joseph Henry Press, {{ISBN|0-309-06556-9}} The presence of cadmium in paints has been used to detect forgeries in paintings alleged to have been produced prior to the 19th century.W. Stanley Taft, James W. Mayer, Richard Newman, Peter Kuniholm, Dusan Stulik (2000) [https://books.google.com/books?id=Z720KVxkInYC The Science of Paintings], Springer, {{ISBN|0-387-98722-3}}
=CdS-CdSe solutions=
CdS and CdSe form solid solutions with each other. Increasing amounts of cadmium selenide, gives pigments verging toward red, for example CI pigment orange 20 and CI pigment red 108.
Such solid solutions are components of photoresistors (light dependent resistors) sensitive to visible and near infrared light.{{citation needed|date=May 2015}}
Safety
Cadmium sulfide is toxic, especially dangerous when inhaled as dust, and cadmium compounds in general are classified as carcinogenic.{{Cite web|url=https://www.cdc.gov/niosh/ipcsneng/neng0404.html|title=CDC - CADMIUM SULFIDE - International Chemical Safety Cards - NIOSH|date=June 26, 2018|archive-url=https://web.archive.org/web/20180626155057/https://www.cdc.gov/niosh/ipcsneng/neng0404.html |archive-date=2018-06-26 }} Problems of biocompatibility have been reported when CdS is used as colors in tattoos.{{cite journal | last1 = Bjornberg | first1 = A | date = Sep 1963 | title = Reactions to light in yellow tattoos from cadmium sulfide | journal = Arch Dermatol | volume = 88 | issue = 3| pages = 267–71 | pmid = 14043617 | doi=10.1001/archderm.1963.01590210025003}} CdS has an LD50 of approximately 7,080 mg/kg in rats - which is higher than other cadmium compounds due to its low solubility.{{Cite web |title=Sicherheitsdatenblatt |url=http://www.alfa.com/content/msds/german/A14544.pdf |website= |archive-url=https://web.archive.org/web/20150724053453/http://www.alfa.com/content/msds/german/A14544.pdf |archive-date=24 July 2015 |url-status=dead}}
References
{{Reflist|30em}}
External links
{{Commons category|Cadmium sulfide}}
- [https://web.archive.org/web/20060317152905/http://www.webelements.com/webelements/compounds/text/Cd/Cd1S1-1306236.html Cadmium(II) sulphide information at Webelements]
- [https://web.archive.org/web/20051015082333/http://www-cie.iarc.fr/htdocs/monographs/vol58/mono58-2.htm IARC Monograph: "Cadmium and Cadmium Compounds"] Last access November 2005.
- [https://web.archive.org/web/20111018214721/http://inchem.org/documents/icsc/icsc/eics0404.htm International Chemical Safety Card 0404]
- [https://web.archive.org/web/20061210213049/http://www.npi.gov.au/database/substance-info/profiles/17.html National Pollutant Inventory - Cadmium and compounds]
- [https://web.archive.org/web/20070110041648/http://www.mod.uk/DefenceInternet/AboutDefence/CorporatePublications/ScienceandTechnologyPublications/InformationSheets/ZincCadmiumSulphideDispersionTrials.htm Defence Internet | About Defence | Zinc Cadmium Sulphide Dispersion Trials] Report by the Academy of Medical Sciences to the Chief Scientific Adviser, Ministry of Defence on the zinc cadmium sulphide dispersion trials undertaken in the United Kingdom between 1953 and 1964.
{{Cadmium compounds}}
{{Sulfides}}
Category:IARC Group 1 carcinogens
Category:Phosphors and scintillators
Category:Zincblende crystal structure