TUNGSTEN SELENIDE Property

Density 

9.32

RTECS 

YO7714000

form 

Powder, 10μm

color 

gray hexagonal, hexane crystals, crystalline

Water Solubility 

Insoluble in water.

Exposure limits

ACGIH: TWA 0.2 mg/m3; TWA 3 mg/m3
NIOSH: IDLH 1 mg/m3; TWA 5 mg/m3; TWA 0.2 mg/m3; STEL 10 mg/m3

CAS DataBase Reference

12067-46-8(CAS DataBase Reference)

EPA Substance Registry System

Tungsten selenide (WSe2) (12067-46-8)

Safety

RIDADR 

UN3283 - class 6.1 - PG 3 - EHS - Selenium compound, solid, n.o.s., HI: all (not BR)

TSCA 

Yes

HazardClass 

9

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H373May cause damage to organs through prolonged or repeated exposure

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

TUNGSTEN SELENIDE Chemical Properties,Usage,Production

Chemical Properties

-325 mesh black powder(s); dry, solid lubricant with exceptional stability at high temperatures, and in high vacuum; used in the form of 99.8% pure material as a sputtering target to produce lubricant films [HAW93] [CER91] [AES93]

Uses

Tungsten(IV) selenide is used as an important compound in electrochemical solar cells. It acts as a stable semiconductor.

Uses

The two dimensional layered inorganic nanomaterials have drawn significant attention recently owing to their thickness dependent physical and chemical properties. They find applications in photocatalysis, phtotovoltaics, gas sensing, lithium ion batteries, field effect transistors, spintronics etc. Transition metal dischalcogenides represent an important class of inorganic 2D materials having the aforementioned applications.

Uses

Owing to the thickness dependent physical and chemical properties, the two dimensional layered inorganic nanomaterials have drawn significant attention recently. They find applications in photocatalysis, phtotovoltaics, gas sensing, lithium ion batteries, field effect transistors, spintronics etc. Transition metal dichalcogenides represent an important class of inorganic 2D materials having aforementioned applications. The CVD grown monolayer films of MoS₂, MoSe₂, WS₂ and WSe₂ on insulating substrates such as SiO₂ and sapphire are well suited for electronic and photovoltaic devices.

Definition

Lamellarstructured, dry, solid lubricant with exceptionally high temperature and high vacuum stability. Retains its lubricity to temperatures as low as ?265C.

Hazard

TLV: 5 mg(W)/m3.

Structure and conformation

Tungsten diselenide, WSe2, has a hexagonal crystalline structure comparable to MoS2. Every tungsten atom is covalently bonded to six selenium ligands in a trigonal prismatic coordination sphere, and each selenium is bonded to three tungsten atoms in a pyramidal geometry. Heating thin films of tungsten under pressure from gaseous selenium and high temperatures ( . 527℃/800K) using the sputter deposition technique leads to the films crystallizing in hexagonal structures with the correct stoichiometric ratio.
W+ 2Se→WSe2