Zinc sulfide

Last updated
Zinc sulfide
ZnS powders2.jpg
ZnS powders containing different concentrations of sulfur vacancies [1]
Names
Other names
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.866 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
RTECS number
  • ZH5400000
UNII
  • InChI=1S/S.Zn/q-2;+2
    Key: DRDVZXDWVBGGMH-UHFFFAOYSA-N
  • [Zn+2].[S-2]
Properties
ZnS
Molar mass 97.474 g/mol
Density 4.090 g/cm3
Melting point 1,850 °C (3,360 °F; 2,120 K) (sublime)
negligible
Band gap 3.54 eV (cubic, 300 K)
3.91 eV (hexagonal, 300 K)
2.3677
Structure
see text
Tetrahedral (Zn2+)
Tetrahedral (S2−)
Thermochemistry
−204.6 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Flash point Non-flammable
Safety data sheet (SDS) ICSC 1627
Related compounds
Other anions
Zinc oxide
Zinc selenide
Zinc telluride
Other cations
Cadmium sulfide
Mercury sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics.

Contents

Structure

Sphalerite, the more common polymorph of zinc sulfide Sphalerite-unit-cell-3D-balls.png
Sphalerite, the more common polymorph of zinc sulfide
Wurtzite, the less common polymorph of zinc sulfide Wurtzite-unit-cell-3D-balls.png
Wurtzite, the less common polymorph of zinc sulfide

ZnS exists in two main crystalline forms. This dualism is an example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically. [2] The transition from the sphalerite form to the wurtzite form occurs at around 1020  °C.

Applications

Luminescent material

Zinc sulfide, with addition of a few ppm of a suitable activator, exhibits strong phosphorescence. The phenomenon was described by Nikola Tesla in 1893, [3] and is currently used in many applications, from cathode ray tubes through X-ray screens to glow in the dark products. When silver is used as activator, the resulting color is bright blue, with maximum at 450 nanometers. Using manganese yields an orange-red color at around 590 nanometers. Copper gives a longer glow, and it has the familiar greenish glow-in-the-dark. Copper-doped zinc sulfide ("ZnS plus Cu") is used also in electroluminescent panels. [4] It also exhibits phosphorescence due to impurities on illumination with blue or ultraviolet light.

Optical material

Zinc sulfide is also used as an infrared optical material, transmitting from visible wavelengths to just over 12 micrometers. It can be used planar as an optical window or shaped into a lens. It is made as microcrystalline sheets by the synthesis from hydrogen sulfide gas and zinc vapour, and this is sold as FLIR-grade (Forward Looking Infrared), where the zinc sulfide is in a milky-yellow, opaque form. This material when hot isostatically pressed (HIPed) can be converted to a water-clear form known as Cleartran (trademark). Early commercial forms were marketed as Irtran-2 but this designation is now obsolete.

Pigment

Zinc sulfide is a common pigment, sometimes called sachtolith. When combined with barium sulfate, zinc sulfide forms lithopone. [5]

Catalyst

Fine ZnS powder is an efficient photocatalyst, which produces hydrogen gas from water upon illumination. Sulfur vacancies can be introduced in ZnS during its synthesis; this gradually turns the white-yellowish ZnS into a brown powder, and boosts the photocatalytic activity through enhanced light absorption. [1]

Semiconductor properties

Both sphalerite and wurtzite are intrinsic, wide-bandgap semiconductors. These are prototypical II-VI semiconductors, and they adopt structures related to many of the other semiconductors, such as gallium arsenide. The cubic form of ZnS has a band gap of about 3.54 electron volts at 300 kelvins, but the hexagonal form has a band gap of about 3.91 electron volts. ZnS can be doped as either an n-type semiconductor or a p-type semiconductor.

History

The phosphorescence of ZnS was first reported by the French chemist Théodore Sidot in 1866. His findings were presented by A. E. Becquerel, who was renowned for the research on luminescence. [6] ZnS was used by Ernest Rutherford and others in the early years of nuclear physics as a scintillation detector, because it emits light upon excitation by x-rays or electron beam, making it useful for X-ray screens and cathode ray tubes. [7] This property made zinc sulfide useful in the dials of radium watches.

Production

Mixtures of zinc and sulfur react pyrotechnically, leaving behind zinc sulfide. The reaction of zinc and sulfur.jpg
Mixtures of zinc and sulfur react pyrotechnically, leaving behind zinc sulfide.

Zinc sulfide is usually produced from waste materials from other applications. Typical sources include smelter, slag, and pickle liquors. [5] As an example, the synthesis of ammonia from methane requires a priori removal of hydrogen sulfide impurities in the natural gas, for which zinc oxide is used. This scavenging produces zinc sulfide:

ZnO + H2S → ZnS + H2O

Laboratory preparation

It is easily produced by igniting a mixture of zinc and sulfur. [8] Since zinc sulfide is insoluble in water, it can also be produced in a precipitation reaction. Solutions containing Zn2+ salts readily form a precipitate ZnS in the presence of sulfide ions (e.g., from H2S).

Zn2+ + S2− → ZnS

This reaction is the basis of a gravimetric analysis for zinc. [9]

Related Research Articles

<span class="mw-page-title-main">Phosphor</span> Luminescent substance

A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or visible light, and cathodoluminescent substances which glow when struck by an electron beam in a cathode-ray tube.

<span class="mw-page-title-main">Sphalerite</span> Zinc-iron sulfide mineral

Sphalerite is a sulfide mineral with the chemical formula (Zn,Fe)S. It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite, calcite, dolomite, quartz, rhodochrosite, and fluorite.

Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. Sulfide also refers to large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (SH−) are the conjugate acids of sulfide.

<span class="mw-page-title-main">Phosphorescence</span> Process in which energy absorbed by a substance is released relatively slowly in the form of light

Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed.

<span class="mw-page-title-main">Zinc oxide</span> White powder insoluble in water

Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.

<span class="mw-page-title-main">Zinc chloride</span> Chemical compound

Zinc chloride is the name of inorganic chemical compounds with the formula ZnCl2. It forms hydrates. Zinc chloride, anhydrous and its hydrates are colorless or white crystalline solids, and are highly soluble in water. Five hydrates of zinc chloride are known, as well as four forms of anhydrous zinc chloride. This salt is hygroscopic and even deliquescent. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

<span class="mw-page-title-main">Cadmium sulfide</span> Chemical compound

Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow salt. 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 18th century.

<span class="mw-page-title-main">Wurtzite</span>

Wurtzite is a zinc and iron sulfide mineral with the chemical formula (Zn,Fe)S, a less frequently encountered structural polymorph form of sphalerite. The iron content is variable up to eight percent. It is trimorphous with matraite and sphalerite.

Lithopone, C.I. Pigment White 5, is a mixture of inorganic compounds, widely used as a white pigment powder. It is composed of a mixture of barium sulfate and zinc sulfide. These insoluble compounds blend well with organic compounds and confer opacity. It was made popular by the cheap production costs, greater coverage. Related white pigments include titanium dioxide, zinc oxide, zinc sulfide, and white lead.

<span class="mw-page-title-main">Mercury sulfide</span> Chemical compound

Mercury sulfide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water.

<span class="mw-page-title-main">Zinc selenide</span> Chemical compound

Zinc selenide is the inorganic compound with the formula ZnSe. It is a lemon-yellow solid although most samples have a duller color due to the effects of oxidation. It is an intrinsic semiconductor with a band gap of about 2.70 eV at 25 °C (77 °F). ZnSe occurs as the rare mineral stilleite, named after Hans Stille.

<span class="mw-page-title-main">Magnesium sulfide</span> Inorganic compound generated in the production of metallic iron

Magnesium sulfide is an inorganic compound with the formula MgS. It is a white crystalline material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron.

<span class="mw-page-title-main">Chalcogenide</span>

A chalcogenide is a chemical compound consisting of at least one chalcogen anion and at least one more electropositive element. Although all group 16 elements of the periodic table are defined as chalcogens, the term chalcogenide is more commonly reserved for sulfides, selenides, tellurides, and polonides, rather than oxides. Many metal ores exist as chalcogenides. Photoconductive chalcogenide glasses are used in xerography. Some pigments and catalysts are also based on chalcogenides. The metal dichalcogenide MoS2 is a common solid lubricant.

<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">Zinc telluride</span> Chemical compound

Zinc telluride is a binary chemical compound with the formula ZnTe. This solid is a semiconductor material with a direct band gap of 2.26 eV. It is usually a p-type semiconductor. Its crystal structure is cubic, like that for sphalerite and diamond.

<span class="mw-page-title-main">Roasting (metallurgy)</span> Process of heating a sulfide ore

Roasting is a process of heating a sulfide ore to a high temperature in the presence of air. It is a step in the processing of certain ores. More specifically, roasting is often a metallurgical process involving gas–solid reactions at elevated temperatures with the goal of purifying the metal component(s). Often before roasting, the ore has already been partially purified, e.g. by froth flotation. The concentrate is mixed with other materials to facilitate the process. The technology is useful in making certain ores usable but it can also be a serious source of air pollution.

Zinc compounds are chemical compounds containing the element zinc which is a member of the group 12 of the periodic table. The oxidation state of zinc in most compounds is the group oxidation state of +2. Zinc may be classified as a post-transition main group element with zinc(II). Zinc compounds are noteworthy for their nondescript appearance and behavior: they are generally colorless, do not readily engage in redox reactions, and generally adopt symmetrical structures.

<span class="mw-page-title-main">Zinc bis(dimethyldithiocarbamate)</span> Chemical compound

Zinc dimethyldithiocarbamate is a coordination complex of zinc with dimethyldithiocarbamate. It is a pale yellow solid that is used as a fungicide, the sulfur vulcanization of rubber, and other industrial applications.

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

Gallium(III) sulfide, Ga2S3, is a compound of sulfur and gallium, that is a semiconductor that has applications in electronics and photonics.

References

  1. 1 2 Wang, Gang; Huang, Baibiao; Li, Zhujie; Lou, Zaizhu; Wang, Zeyan; Dai, Ying; Whangbo, Myung-Hwan (2015). "Synthesis and characterization of ZnS with controlled amount of S vacancies for photocatalytic H2 production under visible light". Scientific Reports. 5: 8544. Bibcode:2015NatSR...5E8544W. doi:10.1038/srep08544. PMC   4339798 . PMID   25712901.
  2. ↑ Wells, A. F. (1984), Structural Inorganic Chemistry (5th ed.), Oxford: Clarendon Press, ISBN   0-19-855370-6 .
  3. ↑ Tesla, Nikola (1894). "The Inventions, Researches, and Writings of Nikola Tesla". Internet Archive. p. 290. Retrieved 2 January 2024.
  4. ↑ Karl A. Franz, Wolfgang G. Kehr, Alfred Siggel, Jürgen Wieczoreck, and Waldemar Adam "Luminescent Materials" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a15_519
  5. 1 2 Gerhard Auer, Peter Woditsch, Axel Westerhaus, Jürgen Kischkewitz, Wolf-Dieter Griebler and Marcel Liedekerke "Pigments, Inorganic, 2. White Pigments" in Ullmann's Encyclopedia of Industrial Chemistry 2009, Wiley-VCH, Weinheim. doi : 10.1002/14356007.n20_n01
  6. ↑ Sidot, T. (1866). "Sur les propriétés de la blende hexagonale". Compt. Rend. 63: 188–189.
  7. ↑ Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 1405. ISBN   978-0-08-022057-4.
  8. ↑ Sur un nouveau procédé de préparation – du sulfure de zinc phosphorescent" by R. Coustal, F. Prevet, 1929
  9. ↑ Mendham, J.; Denney, R. C.; Barnes, J. D.; Thomas, M. J. K. (2000), Vogel's Quantitative Chemical Analysis (6th ed.), New York: Prentice Hall, ISBN   0-582-22628-7
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