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Cadmium sulfide
3D model of the structure of hawleyite
3D model of the structure of greenockite
Other names Cadmium(II) sulfide
Identifiers
CAS number [1306-23-6]
EINECS number 215-147-8
RTECS number EV3150000
Properties
Molecular formula CdS
Molar mass 144. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The EINECS number (for European Inventory of Existing Chemical Substances) is a registry number given to each Chemical substance commercially available in the Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 46 g/mol
Appearance Yellow-orange solid.
Density 4. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 82 g/cm3, solid.
Melting point

1750°C at 100 bar
Boiling point

980°C subl. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid

Solubility in water Insoluble
Structure
Crystal structure Hexagonal
Hazards
EU classification Toxic
Carc. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. Regular hexagon The internal Angles of a regular hexagon (one where all sides and all angles are equal are all 120 ° and the hexagon has 720 degrees Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling Toxicity is the degree to which a substance is able to damage an exposed organism Cat. 2
Muta. Cat. 3
Repr. Cat. 3
Dangerous for
the environment
Flash point non flammable
Related compounds
Other anions Cadmium oxide
Cadmium selenide
Other cations Zinc sulfide
Mercury sulfide
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Cadmium sulfide is a chemical compound with the formula CdS. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Cadmium oxide is an Inorganic compound with the formula CdO CdO is one of the main precursors to other cadmium compounds It crystallizes in a cubic lattice Cadmium selenide ( Cd[[Selenium Se]] is a solid binary compound of cadmium and selenium An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Zinc sulfide (or zinc sulphide is a Chemical compound with the formula Zn[[Sulfur S]] Mercury sulfide, mercuric sulfide, or mercury(II sulfide is a chemical compound composed of the Chemical elements mercury and Sulfur In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly Cadmium (ˈkædmiəm is a Chemical element with the symbol Cd and Atomic number 48 Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Cadmium sulfide is yellow in colour and is a semiconductor. [1] It exists in nature as two different minerals, greenockite[1] and hawleyite. Greenockite is a rare Cadmium Mineral that consists of Cadmium sulfide, CdS in crystalline form Hawleyite is a rare Sulfide mineral in the Sphalerite group dimorphous and easily confused with Greenockite. [2] Cadmium sulfide is a direct band gap semiconductor (gap 2. 42 eV [3]) and has many applications for example in light detectors. A photoresistor or Light Dependent Resistor or CdS Cell is a Resistor whose resistance decreases with increasing incident light intensity It forms thermally stable pigments and with the addition of e. g CdTe, HgS colours ranging from deep red to yellow are formed. Cadmium telluride (CdTe is a Crystalline compound formed from Cadmium and Tellurium with a zinc blende (cubic crystal structure Mercury sulfide, mercuric sulfide, or mercury(II sulfide is a chemical compound composed of the Chemical elements mercury and Sulfur [4]

Contents

Preparation

Cadmium sulfide can be prepared by the precipitation from soluble cadmium(II) salts with sulfide ion and this has been used in the past for the gravimetric analysis of cadmium. [5]
Pigment production usually involves the precipitation of CdS, the washing of the precipitate to remove soluble cadmium salts followed by calcination(roasting) to convert it to the hexagonal form followed by milling to produce a powder. [6] When cadmium sulfide selenides are required the CdSe is co-precipitated with CdS and the cadmium sulfoselenide is created during the calcination step. [6]
Industrially the production of thin films of CdS is required in e. g. photoresistors and CBD, Chemical bath deposition, has been investigated using the hydrolysis of thiourea as the source of sulfide anions and an ammonium salt /ammonia buffer solution to control pH:[7]

Cd2+ + NH3 → [Cd(NH3)4]2+
NH2CS + OH− → SH− + H2O + H2CN2
SH− + OH− → S2− + CdS

Cadmium sulfide can be produced from volatile cadmium alkyls, an example is the reaction of dimethylcadmium with diethyl sulfide to produce a film of CdS using MOCVD techniques. A photoresistor or Light Dependent Resistor or CdS Cell is a Resistor whose resistance decreases with increasing incident light intensity For an individual weak acid or weak base component see Buffering agent. Diethyl sulfide is a clear Flammable Chemical compound with a pungent garlic-like odor Metalorganic vapour phase epitaxy (MOVPE is a Chemical vapour deposition method of epitaxial growth of materials especially Compound semiconductors from [8]

The preparative route and the subsequent treatment of the product, affects the polymorphic form that is produced. It has been asserted in the past that chemical precipitation methods produce the cubic zincblende form [9] however there more recent examples where the hexagonal form is produced, e. g. see[10]

Chemical Properties

Cadmium sulfide is soluble in acids and this has been investigated as a method of extracting the pigment from waste polymers e. g. HDPE pipes [11]:

CdS + HCl → CdCl2 + H2S

When sulfide solutions containing dispersed CdS particles are irradiated with light hydrogen gas is generated: [12]

H2S → H2 + S ΔHf = +9. High-Density Polyethylene ( HDPE) or PolyEthylene High-Density ( PEHD) is a Polyethylene Thermoplastic made from Petroleum 4 kcal/mol

The reaction mechanism proposed involves the electron/hole pairs created when incident light is absorbed by the cadmium sulfide[3] followed by these reacting with water and sulfide:[12]

Production of an electron hole pair
CdS + hν → e− + hole+
Reaction of electron
2e− + 2H2O → H2 + 2OH−
Reaction of hole
2hole+ + 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 (found in the mineral Hawleyite). Zinc sulfide (or zinc sulphide is a Chemical compound with the formula Zn[[Sulfur S]] This article is about the mineral wurtzite For the wurtzite crystal structure see Wurtzite (crystal structure. Greenockite is a rare Cadmium Mineral that consists of Cadmium sulfide, CdS in crystalline form Sphalerite (( Zn, Fe) S) is a Mineral that is the chief Ore of Zinc. Hawleyite is a rare Sulfide mineral in the Sphalerite group dimorphous and easily confused with Greenockite. In both of these forms the Cadmium and sulfur atoms are four coordinate. [13] There is also a high pressure form with the NaCl rock salt structure. [13]

Cadmium sulfide is a direct bandgap semiconductor with a bandgap of 2. In Semiconductor Physics, a direct Bandgap means that the minimum energy of the Conduction band lies directly above the maximum energy of the A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that In Solid state physics and related applied fields a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states 42 eV at 300 K. [3]The magnitude of its band gap means that it appears coloured. [1]
As well as this obvious property others properties result:

Industrial Processes used to produce thin films

Thin films of CdS are required in components such as a photoresistor and solar cells. A photoresistor or Light Dependent Resistor or CdS Cell is a Resistor whose resistance decreases with increasing incident light intensity A solar cell or photovoltaic cell is a device that converts Solar energy into Electricity by the photovoltaic effect. A solar cell or photovoltaic cell is a device that converts Solar energy into Electricity by the photovoltaic effect. Cathodoluminescence is an optical and electrical Phenomenon whereby a beam of Electrons is generated by an Electron gun (e A phosphor is a substance that exhibits the phenomenon of Phosphorescence (sustained glowing after exposure to energized particles such as Electrons Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to Pyroelectricity is the ability of certain materials to generate an Electrical potential when they are heated or cooled Electroluminescence (EL is an Optical phenomenon and Electrical phenomenon in which a material emits light in response to an Electric current passed through Various methods have been used to deposit these thin films, for example (note: there is a large body of research in this area and only representative references are given):

Pigment

CdS is known as Cadmium yellow [1] (CI pigment yellow 37[27]) By adding varying amounts of selenium as selenide it is possible to obtain a range of colors for example CI pigment orange 20 and CI pigment red 108. The sol-gel process is a wet-chemical technique ( Chemical Solution Deposition) for the fabrication of materials (typically a Metal oxide) starting either from a chemical Metalorganic vapour phase epitaxy (MOVPE is a Chemical vapour deposition method of epitaxial growth of materials especially Compound semiconductors from Sputtering is a process whereby Atoms are Ejected from a solid target material due to bombardment of the target by energetic Ions It is commonly used for Screen printing is a printing technique that uses a woven mesh to support an ink blocking stencil Selenium (səˈliniəm is a Chemical element with the Atomic number 34 represented by the chemical symbol Se, an atomic mass of 78 The selenide Ion is Se2&minus A selenide is a chemical compound in which Selenium serves as an Anion with Oxidation number [27]
Synthetic cadmium pigments based on cadmium sulfide are valued for their good thermal stability, light and weather fastness, chemical resistance and high opacity. Cadmium pigments are a class of Pigments that have Cadmium as one of the chemical components [6] The general commercial availability of cadmium sulfide from the 1840's lead to its adoption by artists notably Van Gogh, Monet(in his London series and other works) and Matisse (Bathers by a river 1916-1919)[28] the presence of cadmium in paints has been used to detect forgeries in paintings alleged to have been produced prior to the 19th century. Claude Monet ( French klod mɔnɛ also known as Oscar-Claude Monet or Claude Oscar Monet (14 November 1840 &ndash 5 December 1926 was a founder Henri Matisse (31 December 1869 – 3 November 1954 was a French Artist, known for his use of Colour and his fluid brilliant and original draughtsmanship [29] CdS is used as pigment in plastics[6]

Biological

Cadmium sulfide is produced by sulfate reducing bacteria. [30] This ability is being investigated as a means of producing nano- crystalline CdS [31]

References

  1. ^ a b c d Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN 0123526515
  2. ^ Hawleyite, isometric cadmium sulphide, a new mineral Traill R J, Boyle R W American Mineralogist 40 (1955) 555-559
  3. ^ a b c d Charles Kittel Introduction to Solid State Physics- 7th Edition (1995) Wiley-India ISBN 1081-265-1045-5
  4. ^ Greenwood, N. N. ; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.  
  5. ^ Fred Ibbotson (2007) The Chemical Analysis of Steel-Works' Materials READ BOOKS ISBN 1406781134
  6. ^ a b c d Hugh MacDonald Smith High Performance Pigments 2002 Wiley-VCH ISBN 3527302042
  7. ^ a b Optimization of Chemical Bath Deposited Cadmium Sulfide, I. O. Oladeji, L. Chow, J. Electrochem. Soc. , 144, 7, (1997)
  8. ^ a b Thin CdS films prepared by metalorganic chemical vapor deposition, Hiroshi Uda , Hideo Yonezawa, Yoshikazu Ohtsubo, Manabu Kosaka and Hajimu Sonomura Solar Energy Materials and Solar Cells 75, 1-2, (2003), 219-226 doi:10.1016/S0927-0248(02)00163-0
  9. ^ Paul Klocek (1991) Handbook of Infrared Optical Materials CRC Press ISBN 0824784685
  10. ^ Optical characterization of vacuum evaporated cadmium sulfide films U. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. Pal, R. Silva-González, G. Martínez-Montes, M. Gracia-Jiménez, M. A. Vidal and Sh. Torres Thin Solid Films 305, 1-2, 1997, 345-350,doi:10.1016/S0040-6090(97)00124-7
  11. ^ Extraction of CdS pigment from waste polyethylene Wanrooij P. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. H. P. , Agarwal U. S. , Meuldijk J. , van Kasteren J. M. N. , Lemstra P. J. , Journal of Applied Polymer Science 100, 2 , 1024 – 1031 doi:10.1002/app.22962
  12. ^ a b Mario Schiavello (1985 ) Photoelectrochemistry, Photocatalysis, and Photoreactors: Fundamentals and Developments Springer ISBN:9027719462
  13. ^ a b Wells A. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
  14. ^ Antonio Luque, Steven Hegedus, (2003), Handbook of Photovoltaic Science and Engineering John Wiley and Sons ISBN 0471491969
  15. ^ Photovoltaic Effect in Cadmium Sulfide D. C. Reynolds, G. Leies, L. L. Antes, R. E. Marburger, Phys. Rev. 96, 2, 533 - 534 (1954) doi:10.1103/PhysRev.96.533
  16. ^ C. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. Fouassier,(1994), Luminescence in Encyclopedia of Inorganic Chemistry, John Wiley & Sons ISBN 0471936200
  17. ^ A. K. Cheetham, P. Day 1992 Solid State Chemistry: Compounds Oxford University Press ISBN 0198551665
  18. ^ Temperature Dependence of the Pyroelectric Effect in Cadmium Sulfide W. J. Minkus Phys. Rev. 138, A1277 - A1287 (1965) doi:10.1103/PhysRev.138.A1277
  19. ^ Low-Field Electroluminescence in Insulating Crystals of Cadmium Sulfide, Roland W. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. Smith, Phys. Rev. 105, 900 - 904 (1957) doi:10.1103/PhysRev.105.900
  20. ^ KGP-2: an electron-beam-pumped cadmium sulfide laser, Yu A Akimov, A A Burov, Yu A Drozhbin, V A Kovalenko, S E Kozlov, I V Kryukova, G V Rodichenko, B M Stepanov , V A Yakovlev, Sov. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. J. Quantum Electron. 2 284-285 doi:10.1070/QE1972v002n03ABEH004443
  21. ^ Lasing in single cadmium sulfide nanowire optical cavities, Agarwal R, Barrelet CJ, Lieber CM. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. ,Nano Lett. 2005 5(5):917-20. [1]
  22. ^ Nanosized semiconductor particles in glasses prepared by the sol–gel method: their optical properties and potential uses, Journal of Alloys and Compounds, 341, 1-2,(2002),56-61,doi:10.1016/S0925-8388(02)00059-2
  23. ^ Comparative studies of the properties of CdS films deposited on different substrates by R. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. F. sputtering, Byung-Sik Moon, Jae-Hyeong Lee, Hakkee Jung, Thin Solid Films,511-512,(2006),299-303,doi:10.1016/j.tsf.2005.11.080
  24. ^ Defect reduction in electrochemically deposited CdS thin films by annealing in 02 Fumitaka Goto, Katsunori Shirai, Masaya Ichimura, Solar Energy Materials and Solar Cells, 50, 1-4, (1998), 147-153, doi:10.1016/S0927-0248(97)00136-0
  25. ^ United States Patent 4,086,101, Photovoltaic cells, J. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. F Jordan, C. M Lampkin Issue date: April 25, 1978
  26. ^ US Patent 3208022, High performance photoresistor,Y . T. Sihvonen Issue date: Sep 21, 1965
  27. ^ a b Colour Chemistry R. M. Christie 2001 Royal Society of Chemistry ISBN:0854045732
  28. ^ Sidney Perkowitz 1998 Empire of Light: A History of Discovery in Science and Art, Joseph Henry Press, ISBN 0309065569
  29. ^ W. Stanley Taft, James W. Mayer, Richard Newman, Peter Kuniholm, Dusan Stulik (2000) The Science of Paintings, Springer, ISBN 0387987223
  30. ^ Larry L. Barton 1995 Sulfate reducing bacteria, Springer, ISBN 0306448572
  31. ^ Bacterial Biosynthesis of Cadmium Sulfide Nanocrystals. R. Sweeney , C. Mao , X. Gao , J. Burt , A. Belcher , G. Georgiou , B. Iverson, Chemistry & Biology , 11 , 11 , 1553 - 1559, doi:10.1016/j.chembiol.2004.08.022

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