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Silver molybdate

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Silver molybdate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.962 Edit this at Wikidata
  • InChI=1S/2Ag.Mo.4O/q2*+1;;;;2*-1 checkY
    Key: MHLYOTJKDAAHGI-UHFFFAOYSA-N checkY
  • InChI=1/2Ag.Mo.4O/q2*+1;;;;2*-1/r2Ag.MoO4/c;;2-1(3,4)5/q2*+1;-2
    Key: ^@€×,&#+=+÷×¥× ndnzjsnssi-QWQXGURBAC
  • [Ag+].[Ag+].[O-][Mo]([O-])(=O)=O
Properties
Ag2MoO4
Molar mass 375.67 g/mol
Appearance yellow crystals
Density 6.18 g/cm3, solid
Melting point 483 °C (901 °F; 756 K)
slightly soluble
Structure
cubic
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Silver molybdate is an inorganic compound with the chemical formula Ag2MoO4. It is a yellow solid that crystallizes in the cubic system and exhibits dimorphism. It is often used in glass.[citation needed]

Structure

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Silver molybdate crystals present two types of electronic structure, depending on the pressure conditions to which the crystal is subjected.[1] At room temperature, it exhibits a spinel-type cubic structure, known as β-Ag2MoO4, which is more stable in nature. However, when exposed to high hydrostatic pressure, the tetragonal α-Ag2MoO4 forms as a metastable phase.[2]

Synthesis and properties

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α-Ag2MoO4

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α-Ag2MoO4 can be prepared by solution-phase precipitation under ambient conditions, using 3-bis(2-pyridyl)pyrazine (dpp) as a doping agent.[3] The pH of the starting solution influences the growth and formation processes of distinct heterostructures (brooms, flowers and rods).[4][5]

β-Ag2MoO4

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β-Ag2MoO4 crystals can be prepared by solid-state reaction or oxide mixture at high temperature,[6] melt-quenching,[7] and Czochralski growth.[8]

Additional methods include co-precipitation,[citation needed] microwave-assisted hydrothermal synthesis,[9] a dynamic template route using polymerization of acrylamide assisted templates,[10] and an impregnation/calcination method.[11]

β-Ag2MoO4 microcrystals can be synthesized by precipitation employing polar solvents.[12]

Photocatalytic properties of β–Ag2MoO4 crystals can be improved through hydrothermal processing at different temperatures.[13] The replacement of Ag atoms with Zn to form silver-zinc molybdate [β–(Ag2−2xZnx)MoO4] microcrystals by a sonochemical method also leads to improvements.[14] These crystals are able to degrade rhodamine B and Remazol Brilliant Violet 5R.[13][14]

Ag-Ag2MoO4 composites

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Ag-Ag2MoO4 composites can be prepared by microwave-assisted hydrothermal synthesis. These composites present photocatalytic activity for the degradation of rhodamine B under visible light.[15]

Other properties

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Ag2MoO4 mixed with graphite acts as a good lubricant for Ni-based composites, improving the tribological properties of the system.[16]

References

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  1. ↑ Arora, A. K.; Nithya, R.; Misra, Sunasira; Yagi, Takehiko (2012-12-01). "Behavior of silver molybdate at high-pressure". Journal of Solid State Chemistry. 196: 391–397. Bibcode:2012JSSCh.196..391A. doi:10.1016/j.jssc.2012.07.003.
  2. ↑ Beltrán, Armando; Gracia, Lourdes; Longo, Elson; Andrés, Juan (2014-02-20). "First-Principles Study of Pressure-Induced Phase Transitions and Electronic Properties of Ag2MoO4". The Journal of Physical Chemistry C. 118 (7): 3724–3732. doi:10.1021/jp4118024. ISSN 1932-7447.
  3. ↑ Ng, Choon Hwee Bernard; Fan, Wai Yip (2015-06-03). "Uncovering Metastable α-Ag2MoO4 Phase Under Ambient Conditions. Overcoming High Pressures by 2,3-Bis(2-pyridyl)pyrazine Doping". Crystal Growth & Design. 15 (6): 3032–3037. doi:10.1021/acs.cgd.5b00455. ISSN 1528-7483.
  4. ↑ Singh, D. P.; Sirota, B.; Talpatra, S.; Kohli, P.; Rebholz, C.; Aouadi, S. M. (2012-03-09). "Broom-like and flower-like heterostructures of silver molybdate through pH controlled self assembly". Journal of Nanoparticle Research. 14 (4): 781. Bibcode:2012JNR....14..781S. doi:10.1007/s11051-012-0781-0. hdl:10533/128243. ISSN 1388-0764. S2CID 96310636.
  5. ↑ Fodjo, Essy Kouadio; Li, Da-Wei; Marius, Niamien Paulin; Albert, Trokourey; Long, Yi-Tao (2013-01-23). "Low temperature synthesis and SERS application of silver molybdenum oxides". Journal of Materials Chemistry A. 1 (7): 2558–2566. doi:10.1039/c2ta01018f.
  6. ↑ Suthanthiraraj, S. Austin; Premchand, Y. Daniel (2004-05-01). "Molecular structural analysis of 55mol% CuI-45mol% Ag2MoO4 solid electrolyte using XPS and laser raman techniques". Ionics. 10 (3–4): 254–257. doi:10.1007/BF02382825. ISSN 0947-7047. S2CID 95974644.
  7. ↑ Rocca, F; Kuzmin, A; Mustarelli, P; Tomasi, C; Magistris, A (1999-06-01). "XANES and EXAFS at Mo K-edge in (AgI)1−x(Ag2MoO4)x glasses and crystals". Solid State Ionics. 121 (1–4): 189–192. doi:10.1016/S0167-2738(98)00546-3.
  8. ↑ Brown, Stephen; Marshall, Alison; Hirst, Philip (1993-12-20). "The growth of single crystals of lead molybdate by the Czochralski technique". Materials Science and Engineering: A. 173 (1–2): 23–27. doi:10.1016/0921-5093(93)90179-I.
  9. ↑ Gouveia, A. F.; Sczancoski, J. C.; Ferrer, M. M.; Lima, A. S.; Santos, M. R. M. C.; Li, M. Siu; Santos, R. S.; Longo, E.; Cavalcante, L. S. (2014-06-02). "Experimental and Theoretical Investigations of Electronic Structure and Photoluminescence Properties of β-Ag2MoO4 Microcrystals". Inorganic Chemistry. 53 (11): 5589–5599. doi:10.1021/ic500335x. ISSN 0020-1669. PMID 24840935.
  10. ↑ Jiang, Hao; Liu, Jin-Ku; Wang, Jian-Dong; Lu, Yi; Yang, Xiao-Hong (2015-07-14). "Thermal perturbation nucleation and growth of silver molybdate nanoclusters by a dynamic template route". CrystEngComm. 17 (29): 5511–5521. doi:10.1039/c5ce00039d.
  11. ↑ Zhao, Songjian; Li, Zhen; Qu, Zan; Yan, Naiqiang; Huang, Wenjun; Chen, Wanmiao; Xu, Haomiao (2015-10-15). "Co-benefit of Ag and Mo for the catalytic oxidation of elemental mercury". Fuel. 158: 891–897. doi:10.1016/j.fuel.2015.05.034.
  12. ↑ Cunha, F. S.; Sczancoski, J. C.; Nogueira, I. C.; Oliveira, V. G. de; Lustosa, S. M. C.; Longo, E.; Cavalcante, L. S. (2015-10-28). "Structural, morphological and optical investigation of β-Ag 2 MoO 4 microcrystals obtained with different polar solvents". CrystEngComm. 17 (43): 8207–8211. doi:10.1039/c5ce01662b.
  13. 1 2 Sousa, Giancarlo da Silva; Nobre, Francisco Xavier; Júnior, Edgar lves Araújo; Sambrano, Julio Ricardo; Albuquerque, Anderson dos Reis; Bindá, Rosane dos Santos; Couceiro, Paulo Rogério da Costa; Brito, Walter Ricardo; Cavalcante, Laecio Santos; Santos, Maria Rita Morais; Matos, Jose Milton Elias (20 July 2018). "Hydrothermal synthesis, structural characterization and photocatalytic properties of β--Ag2MoO4 microcrystals: Correlation between experimental and theoretical data". Arabian Journal of Chemistry. 13: 2806–2825. doi:10.1016/j.arabjc.2018.07.011.
  14. 1 2 Coimbra, D.W.; Cunha, F.S.; Sczancoski, J.C.; de Carvalho, J.F.S.; de Macêdo, F.R.C.; Cavalcante, L.S. (2019). "Structural refinement, morphology and photocatalytic properties of β-(Ag2−2xZnx)MoO4 microcrystals synthesized by the sonochemical method". Journal of Materials Science: Materials in Electronics. 30 (2): 1322–1344. doi:10.1007/s10854-018-0401-6. S2CID 139865569.
  15. ↑ Li, ZhaoQian; Chen, XueTai; Xue, Zi-Ling (2013-02-22). "Microwave-assisted hydrothermal synthesis of cube-like Ag-Ag2MoO4 with visible-light photocatalytic activity". Science China Chemistry. 56 (4): 443–450. doi:10.1007/s11426-013-4845-5. ISSN 1674-7291. S2CID 100948033.
  16. ↑ Liu, Eryong; Gao, Yimin; Jia, Junhong; Bai, Yaping (2013-03-24). "Friction and Wear Behaviors of Ni-based Composites Containing Graphite/Ag2MoO4 Lubricants". Tribology Letters. 50 (3): 313–322. doi:10.1007/s11249-013-0131-0. ISSN 1023-8883. S2CID 137297325.
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