Platinum diselenide
Names | |
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Other names
Platinum(IV) selenide
Sudovikovite | |
Identifiers | |
3D model (
JSmol ) |
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PubChem CID
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Properties | |
PtSe2 | |
Molar mass | 353.026 g·mol−1 |
Appearance | opaque metallic yellowish white |
Density | 9.54 |
Melting point | decomposes |
insoluble | |
Band gap | 0 (bulk) 1.3 eV monolayer |
Structure | |
space group P3m1 164 hexagonal | |
a = 3.728[1], c = 5.031
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octahedral | |
Related compounds | |
Other anions
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platinum disulfide platinum ditelluride PtSeTe PtSSe |
Other cations
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palladium diselenide NiSeTe
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Related platinum selenides
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Luberoite Pt5Se4 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Platinum diselenide is a
Synthesis
Minozzi was the first to report synthesising platinum diselenide from the elements in 1909.[2]
Platinum diselenide can be formed by heating thin foils of platinum in selenium vapour at 400 °C.[3][4]
A platinum
In addition to these selenization methods, PtSe2 can be made by precipitation in water solution of Pt(IV) treated with
Natural occurrence
Platinum diselenide occurs naturally as the mineral Sudovikovite. It was named after Russian petrologist, N.G. Sudovikov who lived from 1903 to 1966. The mineral's hardness is 2 to 21/2. Sudovikovite was found in the Srednyaya Padma mine, Velikaya Guba uranium-vanadium deposit, Zaonezhie peninsula,
Properties
Platinum diselenide forms crystals in the cadmium iodide structure. This means that the substance forms layers. Each of the monolayers has a central bed of platinum atoms, with a sheet of selenium atoms above and below. This structure is also called "1T" and has an trigonal structure. The layers are only weakly bonded together, and it is possible to exfoliate layers to bilayers or monolayers.[7]
In bulk the material is semi-metallic, but when reduced to few layers it becomes a semiconductor.[7][8] The conductivity of the bulk material is 620,000 S/m.[9]
The XPS spectrum shows a peak at 72.3 eV from Pt 4f core, and also has peaks from Pt 5p3/2[7] and Se 3d3/2 and 3d5/2 at 55.19and 54.39 eV.[5]
Phonon vibrations are designated by the infrared active A2u (Se vibrating out of plane opposite to Pt), Eu (in layer vibration, Se opposite to Pt), and Raman active A1g (Se top and bottom atoms moving out of plane in opposite directions 205 cm−1), and Eg (In plane, top and bottom Se atoms moving opposite 175 cm−1). In the
The band gap is calculated as 1.2 eV for monolayers, and 0.21 eV for bilayers. For a trylayer or thicker the substance loses a bandgap and becomes semimetallic.[5]
PtSe2 can change its conductance in the presence of particular gases, such as nitrogen dioxide. Within a few seconds, NO2 absorbs on the surface of the PtSe2 material and lowers the resistance. When the gas is absent, high resistance returns again in about a minute.[3]
The Seebeck coefficient of PtSe2 is 40 μV/K.[10]
Although pristine platinum diselenide is nonmagnetic, the presence of platinum vacancies and strain were predicted to induce magnetism.[11] Later magneto-transport studies [12] have indeed shown that defective PtSe2 exhibits magnetic properties. Due to RKKY interaction between magnetic Pt-vacancies, this results in layer-dependent ferromagnetic or anti-ferromagnetic behavior.
Monolayers of platinum diselenide show helical spin texture, which is not expected for
Reactions
Water can physisorb to the surface of platinum diselenide with an energy of −0.19 eV, and similarly for oxygen with energy −0.13 eV. Water and oxygen do not react at toom temperature, because significant energy would be required to break apart the molecules.[9]
Comparison
Palladium diselenide has a different modified
More complex substances with platinum and selenium also exist, including the quaternary chalcogenides Rb2Pt3USe6 and Cs2Pt3USe6[15]
Jacutingaite is a ternary platinum selenide HgPtSe3.[16]
Use
Platinum diselenide can be utilized for boardband photodetector up to mid-infrared (MIR) region with stability in ambient condition.
Combined with graphene it can be a photocatalyst, converting water and oxygen to reactive hydroxyl radical and superoxide. This reaction works when photons produce holes and electrons. The holes can neutralise hydroxide to make hydroxyl, and the electrons attach to oxygen to make superoxide. These reactive species can mineralise organic matter.
References
- .
- ^
- ^ a b "Ultra-fast, ultra-sensitive PtSe2 gas sensors". PhysOrg. 13 January 2017. Retrieved 17 March 2017.
- S2CID 22259155.
- ^ PMID 25996311.
- ^ "Sudovikovite: Sudovikovite mineral information and data". www.mindat.org. Retrieved 19 March 2017.
- ^ S2CID 119271642.
- PMID 29500434.
- ^ S2CID 9237296.
- .
- .
- PMID 31209281.
- PMID 28139646.
- ^ Dey, Sandip; Jain, Vimal K. (2004). "Platinum group metal chalcogenides" (PDF). Platinum Metals Review. 48 (1): 16–29.
- S2CID 29859041.
- .
- S2CID 252739491.