Molybdenum disulfide and Hafnium disulfide: Difference between pages
(Difference between pages)
Content deleted Content added
m r2.7.1) (robot Adding: fr:Disulfure de molybdène |
No edit summary |
||
| Line 1: | Line 1: | ||
{{redirect|HfS2|the radio station|HFS2}} |
|||
{{chembox |
{{chembox |
||
| Verifiedfields = changed |
|||
| verifiedrevid = 444016513 |
|||
| Watchedfields = changed |
|||
| Name = Molybdenum disulfide |
|||
| verifiedrevid = 444652607 |
|||
| ImageFile = MoS2chips.jpg |
|||
| Name = Hafnium disulfide |
|||
| ImageFile2 = Molybdenite-3D-balls.png |
|||
| ImageFile = HfS2chips.jpg |
|||
| ImageSize = 200px |
|||
| ImageFile2 = HfS2 structure.png |
|||
| ImageName = Molybdenum disulfide |
|||
| ImageSize = 240px |
|||
| IUPACName = Molybdenum disulfide |
|||
| ImageSize2 = 240px |
|||
| OtherNames = [[Molybdenite]] |
|||
| ImageName = |
|||
| Section1 = {{Chembox Identifiers |
|||
| IUPACName = Hafnium disulfide |
|||
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
|||
| OtherNames = |
|||
| ChemSpiderID = 14138 |
|||
|Section1={{Chembox Identifiers |
|||
| InChI = 1/Mo.2S/rMoS2/c2-1-3 |
|||
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
|||
| InChIKey = CWQXQMHSOZUFJS-FRBXWHJUAU |
|||
| ChemSpiderID = 8374205 |
|||
| InChI = |
|||
| InChIKey = |
|||
| ChEBI_Ref = {{ebicite|correct|EBI}} |
| ChEBI_Ref = {{ebicite|correct|EBI}} |
||
| ChEBI = |
| ChEBI = |
||
| SMILES = S=[ |
| SMILES = S=[Hf]=S |
||
| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
||
| StdInChI = 1S/ |
| StdInChI = 1S/Hf.2S |
||
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
||
| StdInChIKey = |
| StdInChIKey = |
||
| CASNo = |
| CASNo = 18855-94-2 |
||
| |
| CASNo_Ref = {{cascite|correct|CAS}} |
||
| |
| RTECS = |
||
| PubChem = 101811522 |
|||
}} |
}} |
||
| |
|Section2={{Chembox Properties |
||
| |
| Formula = HfS<sub>2</sub> |
||
| |
| MolarMass = 246.62 g/mol<ref name=b92>{{RubberBible92nd|page=4.66}}</ref> |
||
| |
| Appearance = Brown solid |
||
| |
| Density = 6.03 g/cm<sup>3</sup><ref name=b92/> |
||
| MeltingPtC = |
|||
| MeltingPt = 1185 °C decomp. |
|||
| BandGap = ~1.8 eV (indirect)<ref>{{cite journal|title=Indirect absorption edge of ZrS<sub>2</sub> and HfS<sub>2</sub>|journal=Solid State Communications|volume=63|issue=4|pages=315|doi=10.1016/0038-1098(87)90916-1|year=1987|last1=Terashima|first1=K.|last2=Imai|first2=I.|bibcode=1987SSCom..63..315T}}</ref> |
|||
| MeltingPt_notes = |
|||
| Solubility = |
|||
| SolubleOther = |
|||
| MagSus = |
|||
}} |
}} |
||
| |
|Section3={{Chembox Structure |
||
| CrystalStruct = [[Pearson symbol|hP3]], [[space group|P{{overline|3}}m1]], No 164<ref name=str>{{Cite journal | doi = 10.1016/0022-4596(84)90176-2| title =Anomalies in the properties of Hf(S<sub>2−x</sub>Te<sub>x</sub>)<sub>1-y</sub> and Hf(Se<sub>2−x</sub>Te<sub>x</sub>)<sub>1-y</sub> near the metal-insulator transition| journal =Journal of Solid State Chemistry| volume =54| issue =3| pages =438| year =1984| last1 =Hodul| first1 =David T.| last2 =Stacy| first2 =Angelica M.| bibcode =1984JSSCh..54..438H}}</ref> |
|||
| CrystalStruct = [[Hexagonal crystal system|Hexagonal]], [[Pearson symbol|hP6]], [[space group]] P6<sub>3</sub>/mmc, No 194 |
|||
| LattConst_a = 0.363 nm |
|||
| Coordination = [[Trigonal prism]]atic (Mo<sup>IV</sup>)<br/>Pyramidal (S<sup>2−</sup>) |
|||
| LattConst_c = 0.584 nm |
|||
| UnitCellFormulas = 1 |
|||
| Coordination = |
|||
}} |
}} |
||
| |
|Section7={{Chembox Hazards |
||
| ExternalSDS = |
|||
| ExternalMSDS = [http://www.gfschemicals.com/Search/MSDS/1468MSDS.PDF External MSDS] |
|||
| NFPA-H = |
|||
| EUIndex = not listed |
|||
| |
| NFPA-F = |
||
| |
| NFPA-R = |
||
| |
| FlashPt = |
||
| NFPA-H = |
|||
| NFPA-F = |
|||
| NFPA-R = |
|||
| FlashPt = |
|||
}} |
}} |
||
| |
|Section8={{Chembox Related |
||
| |
| OtherAnions = [[Hafnium dioxide]] |
||
| |
| OtherCations = [[Tungsten disulfide]]<br/>[[Molybdenum disulfide]] |
||
| OtherFunction = |
|||
| OtherFunctn = [[Graphite]] |
|||
| OtherFunction_label = |
|||
| Function = [[lubricant]]s |
|||
}} |
}} |
||
}} |
}} |
||
'''Hafnium disulfide''' is an [[inorganic chemistry|inorganic compound]] of [[hafnium]] and [[sulfur]]. It is a layered di[[chalcogenide]] with the [[chemical formula]] is HfS<sub>2</sub>. A few atomic layers of this material can be exfoliated using the standard [[Graphene production techniques#Adhesive tape|Scotch Tape technique]] (see [[graphene]]) and used for the fabrication of a [[field-effect transistor]].<ref>{{cite journal|doi=10.1038/srep22277|title=Few-layer HfS<sub>2</sub> transistors|journal=Scientific Reports|volume=6|pages=22277|year=2016|last1=Kanazawa|first1=Toru|last2=Amemiya|first2=Tomohiro|last3=Ishikawa|first3=Atsushi|last4=Upadhyaya|first4=Vikrant|last5=Tsuruta|first5=Kenji|last6=Tanaka|first6=Takuo|last7=Miyamoto|first7=Yasuyuki|pmid=26926098|pmc=4772098|bibcode=2016NatSR...622277K}}</ref> High-yield synthesis of HfS<sub>2</sub> has also been demonstrated using liquid phase exfoliation, resulting in the production of stable few-layer HfS<sub>2</sub> flakes.<ref>{{cite journal|last1=Kaur|first1=Harneet|title=High Yield Synthesis and Chemical Exfoliation of Two-Dimensional Layered Hafnium Disulphide|journal=Nano Research|arxiv=1611.00895|doi=10.1007/s12274-017-1636-x|year=2017|s2cid=99414438 }}</ref> Hafnium disulfide powder can be produced by reacting [[hydrogen sulfide]] and hafnium oxides at 500–1300 °C.<ref>{{Cite journal|last1=Kaminskii|first1=B. T.|last2=Prokof'eva|first2=G. N.|last3=Plygunov|first3=A. S.|last4=Galitskii|first4=P. A.|date=1973-07-01|title=Manufacture of zirconium and hafnium sulfide powders|journal=Soviet Powder Metallurgy and Metal Ceramics|volume=12|issue=7|pages=521–524|doi=10.1007/BF00796747|s2cid=95277086 }}</ref> |
|||
== References == |
|||
'''Molybdenum disulfide''' is the [[inorganic chemistry|inorganic compound]] with the [[chemical formula|formula]] MoS<sub>2</sub>. This black crystalline [[sulfide]] of [[molybdenum]] occurs as the mineral [[molybdenite]]. It is the principal ore from which molybdenum metal is extracted. The natural amorphous form is known as the rarer mineral jordisite. MoS<sub>2</sub> is less reactive than other [[transition metal]] [[chalcogenide]]s, being unaffected by dilute [[acid]]s. In its appearance and feel, molybdenum disulfide is similar to [[graphite]]. Indeed, like graphite, it is widely used as a solid lubricant because of its low friction properties, sometimes to relatively high temperatures. |
|||
{{Commons category|Hafnium disulfide}} |
|||
{{reflist}} |
|||
{{Hafnium compounds}} |
|||
==Production== |
|||
{{Sulfides}} |
|||
[[Image:Molly Hill molybdenite.JPG|thumb|left|Molybdenite]] |
|||
Molybdenite ore is processed by [[Froth flotation|flotation]] to give relatively pure MoS<sub>2</sub>, the main contaminant being carbon. MoS<sub>2</sub> also arises by the thermal treatment of virtually all molybdenum compounds with [[hydrogen sulfide]]. |
|||
[[Molybdenite]] is the principal ore from which molybdenum metal is extracted.<ref name=ullmann>Roger F. Sebenik et al. "Molybdenum and Molybdenum Compounds" in Ullmann's Encyclopedia of Chemical Technology 2005; Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a16_655}}</ref> |
|||
{{DEFAULTSORT:Hafnium disulfide}} |
|||
==Structure and physical properties== |
|||
[[Category:Hafnium compounds]] |
|||
In MoS<sub>2</sub>, each Mo(IV) center occupies a trigonal prismatic coordination sphere, being bound to six sulfide ligands. Each sulfur centre is pyramidal, being connected to three Mo centres. In this way, the trigonal prisms are interconnected to give a layered structure, wherein molybdenum atoms are sandwiched between layers of sulfur atoms.<ref>{{cite book| author = Wells, A.F. | year =1984| title = Structural Inorganic Chemistry| location = Oxford| publisher = Clarendon Press| isbn = 0-19-855370-6}}</ref> Because of the weak [[van der Waals force|van der Waals]] interactions between the sheets of sulfide atoms, MoS<sub>2</sub> has a low [[coefficient of friction]], resulting in its lubricating properties. Other layered inorganic materials exhibit lubricating properties (collectively known as [[solid lubricant]]s or [[dry lubricant]]s) including graphite, which requires volatile additives, and hexagonal [[boron nitride]].<ref>{{cite book| author = Thorsten Bartels ''et al.'' | chapter =Lubricants and Lubrication| title = Ullmann's Encyclopedia of Industrial Chemistry| publisher = Wiley VCH| location = Weinheim| year = 2002| doi = 10.1002/14356007.a15_423}}</ref> |
|||
[[Category:Disulfides]] |
|||
[[Category:Transition metal dichalcogenides]] |
|||
MoS<sub>2</sub> is diamagnetic and a [[semiconductor]]. |
|||
[[Category:Monolayers]] |
|||
==Chemical properties== |
|||
Molybdenum disulfide is stable in air or oxygen at normal conditions, but reacts with oxygen upon heating forming [[molybdenum trioxide]]: |
|||
:2 MoS<sub>2</sub> + 9 O<sub>2</sub> → 2 MoO<sub>3</sub> + 4 SO<sub>3</sub> |
|||
Chlorine attacks molybdenum disulfide at elevated temperatures to form molybdenum pentachloride: |
|||
:2 MoS<sub>2</sub> + 7 Cl<sub>2</sub> → 2 MoCl<sub>5</sub> + 2 S<sub>2</sub>Cl<sub>2</sub> |
|||
Molybdenum disulfide reacts with alkyl lithium under controlled conditions to form intercalation compounds Li<sub>x</sub>MoS<sub>2</sub>. With [[n-Butyllithium|butyl lithium]], the product is LiMoS<sub>2</sub>.<ref name=ullmann/> |
|||
==Use as lubricant== |
|||
MoS<sub>2</sub> with particle sizes in the range of 1–100 µm is a common [[dry lubricant]]. Few alternatives exist that can confer the high lubricity and stability up to 350 °C in oxidizing environments. Sliding friction tests of MoS<sub>2</sub> using a [[pin on disc tester]] at low loads (0.1–2 N) give friction coefficient values of <0.1.<ref>{{cite book| author =G. L. Miessler and D. A. Tarr | title =Inorganic Chemistry, 3rd Ed| publisher= Pearson/Prentice Hall publisher| isbn = 0-13-035471-6| year =2004}}</ref><ref>{{cite book| author =Shriver, D. F.; Atkins, P. W.; Overton, T. L.; Rourke, J. P.; Weller, M. T.; Armstrong, F. A. | title =Inorganic Chemistry| publisher = W. H. Freeman| location= New York| year = 2006| isbn = 0-7167-4878-9}}</ref> |
|||
Molybdenum disulfide is often a component of blends and composites where low friction is sought. A variety of [[oil]]s and [[grease (lubricant)|grease]]s are used, because they retain their lubricity even in cases of almost complete oil loss, thus finding a use in critical applications such as [[aircraft engine]]s. When added to [[plastic]]s, MoS<sub>2</sub> forms a [[composite material|composite]] with improved strength as well as reduced friction. Polymers that have been filled with MoS<sub>2</sub> include [[nylon]] (with the [[trade name]] [[Nylatron]]), [[Teflon]], and [[Vespel]]. Self-lubricating composite coatings for high-temperature applications have been developed consisting of molybdenum disulfide and [[titanium nitride]] by [[chemical vapor deposition]].<ref>{{cite web| accessdate = 2009-06-06| url = http://www.ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr19950329-01 | title= ORNL develops self-lubricating coating for engine parts}}</ref> |
|||
===Specific uses=== |
|||
MoS<sub>2</sub> is often used in [[two-stroke engine]]s; e.g., motorcycle engines. It is also used in [[Constant-velocity joint|CV]] and [[universal joint]]s. MoS<sub>2</sub>-coatings allow [[bullet]]s easier passage through the rifle barrel causing less barrel fouling allowing the barrel to retain ballistic accuracy much longer.<ref>{{cite web| accessdate = 2009-06-06| url = http://www.norma.cc/content.asp?Typ=27&Lang=2&DocumentID=398&Submeny=3&Rubrik=Diamond%20line&Title=Barrels%20retain%20accuracy%20longer%20with%20Diamond%20Line| title = Barrels retain accuracy longer with Diamond Line| publisher=Norma}}</ref> This resistance to barrel fouling comes at a cost of lower muzzle velocity with the same load due to a decreased chamber pressure.MoS<sub>2</sub> is applied to bearings in [[ultra-high vacuum]] applications up to 10<sup>−9</sup> torr (at −226 to 399 °C). The lubricant is applied by burnishing and the excess is wiped from the bearing surface.<ref>{{cite web| accessdate = 2009-08-18| url = http://www.polysi.com/dow%20corning%20msds%20sheets/.../DC%20Z%20powder.pdf| title = DOW CORNING Z moly-powder| publisher=Dow Corning}} {{Dead link|date=September 2010|bot=H3llBot}}</ref> |
|||
MoS<sub>2</sub> is also used in ski glide wax. Many ski wax manufacturers use it now to prevent static buildup in dry snow conditions and to add glide when sliding in dirty snow.<ref>{{cite web| accessdate = 2011-01-06| url = http://www.swixsport.com/dav/8dde5f4784.pdf| title = On dry lubricants in ski waxes| publisher=Swix Sport AX}}</ref><ref>{{cite web| accessdate = 2011-01-06| url = http://www.tokous.com/Chemical%20Makeup%20of%20Glide%20Wax.htm| title = GENERAL INFORMATION ON WAX| publisher=Toko}}</ref> |
|||
==Use in petrochemistry== |
|||
Synthetic MoS<sub>2</sub> is employed as a [[catalyst]] for desulfurization in [[Petrochemistry|petroleum refineries]]; e.g., [[hydrodesulfurization]].<ref>{{cite book| author =Topsøe, H.; Clausen, B. S.; Massoth, F. E. | title =Hydrotreating Catalysis, Science and Technology| publisher = Springer-Verlag| location= Berlin| year = 1996}}</ref> The effectiveness of the MoS<sub>2</sub> catalysts is enhanced by [[Doping (semiconductor)|doping]] with small amounts of cobalt or nickel and the intimate mixture is supported on [[alumina]]. Such catalysts are generated in situ by treating molybdate/cobalt or nickel-impregnated alumina with H<sub>2</sub>S or an equivalent reagent. |
|||
== Future developments == |
|||
=== Lubrication === |
|||
With the exception of hexagonal boron nitride, there are currently no clear lubrication alternatives to molybdenum disulfide or the very similar [[tungsten disulfide]] that can resist temperatures higher than 350 °C in oxidizing environments. Research has been conducted on [[compacted oxide layer glaze]]s, which form during metallic surface sliding wear at several hundred degrees Celsius. However, because these oxide layers are physically unstable, their use has currently not proven practical. |
|||
=== Photocatalyst === |
|||
When combined with [[cadmium sulfide]], MoS<sub>2</sub> increases the rate of photocatalytic [[hydrogen production]].<ref>{{cite web| accessdate = 2009-06-06| url = http://english.cas.ac.cn/eng2003/news/detailnewsb.asp?InfoNo=27192| title = CAS researchers discover low-cost photocatalyst for H2 production| publisher = Chinese Academy of Sciences}} {{Dead link|date=September 2010|bot=H3llBot}}</ref> |
|||
=== Electronics === |
|||
Molybdenum disulfide has been found to have semi-conductive properties with distinct advantages over traditional silicon or germanium for use in electronics applications.<ref name="physorg">{{cite web|url=http://www.physorg.com/news/2011-01-transistors-alternative-silicon-graphene.html|title=New transistors: An alternative to silicon and better than graphene|publisher=[[Physorg.com]]|date=January 30, 2011|accessdate=January 30, 2011}}</ref> |
|||
==References== |
|||
{{reflist|2}} |
|||
==Further reading== |
|||
*{{cite book| page =50| url =http://books.google.com/?id=IyB_rPo3osUC&pg=PA50| title =Progress in intercalation research| author = W. Müller-Warmuth, R. Schöllhorn| publisher= Springer| year = 1994| isbn =0792323572}} |
|||
{{Molybdenum compounds}} |
|||
{{DEFAULTSORT:Molybdenum Disulfide}} |
|||
[[Category:Molybdenum compounds]] |
|||
[[Category:Sulfides]] |
|||
[[Category:Non-petroleum based lubricants]] |
|||
[[Category:Dry lubricants]] |
|||
[[Category:Semiconductor materials]] |
|||
[[de:Molybdän(IV)-sulfid]] |
|||
[[fr:Disulfure de molybdène]] |
|||
[[nl:Molybdeen(IV)sulfide]] |
|||
[[ja:硫化モリブデン(IV)]] |
|||
[[ru:Сульфид молибдена(IV)]] |
|||
[[fi:Molybdeenidisulfidi]] |
|||
[[zh:二硫化钼]] |
|||