1314-35-8 Usage
Description
Tungsten trioxide, also known as Tungsten(VI) oxide (WO3), is a semiconducting material with excellent electrochromic properties. It is a bright canary-yellow colored powder that becomes dark-orange when heated and regains its original color upon cooling. Tungsten trioxide is a chemical compound consisting of oxygen and the transition metal tungsten. It occurs naturally but rarely in the form of hydrates in some kinds of minerals. It has various applications in different industries.
Uses
1. Tungsten and Tungstate Manufacturing:
Tungsten trioxide is used in the production of tungsten metal powders and tungstates. The majority of metallic tungsten is used to make cemented carbide parts, while the remainder is used in manufacturing components for lighting, electrical, electronic, heating, and welding applications.
2. X-ray Screens and Fireproofing Fabrics:
Tungsten trioxide is used in the manufacture of tungstates, which are used as X-ray screens and for fireproofing fabrics.
3. Ceramic Pigments:
Tungsten trioxide is used as a ceramic pigment due to its bright canary-yellow color.
4. Solar Energy Absorption:
Nanowires of Tungsten (VI) oxide are capable of absorbing a higher percentage of the sun's radiation since it absorbs blue light.
5. Tungsten Alloys:
Tungsten oxide (WO3) is used to make tungsten alloys and is also used as fireproofing for various surfaces.
6. Electrochromic Windows:
Tungsten trioxide can be used in the preparation of electrochromic windows or smart windows, which are energy-efficient and can control the amount of light passing through them.
7. Semiconductors:
Tungsten trioxide, together with titanium dioxide, has the potential to become an efficient photo-catalyst under visible light irradiation.
8. High-Performance Lithium-Ion Batteries:
Recent studies have shown that mesoporous tungsten trioxide polyaniline nanocomposite can be used as an anode material for high-performance lithium-ion batteries.
Physical Properties:
Tungsten trioxide is a heavy yellow powder with a density of 7.2 g/cm3. It melts at 1,472°C and is insoluble in water, slightly soluble in acids, and soluble in caustic alkalies.
Chemical Properties:
Tungsten trioxide is a noncombustible material that is insoluble in water and soluble in caustic alkalies. It can be converted into the blue oxide and brown oxide when heated in a current of hydrogen. It can also be transformed into different oxides when acted upon by reducing agents such as zinc, hydrochloric acid, stannous chloride, or organic matter.
hermochromism
hermochromism is the property of substances to changecolour due to a change in temperature and WO3is an attractive example for this property. On cooling the oxide by liquid nitrogen down to -196°C, a sudden change occurs from yellow to white, which then alters to a bluish-white colour between -50 and -27°C. At room temperature it becomes pale lemon-yellow again. On furtherheating to 200 – 300°C, WO3becomes dark yellow, changingto a deep orange colour at 400 to 500°C .
These reversible colour changes are linked to changes in the electronic properties of WO3 which alter due to changesof the internal symmetry of the WO3crystals (through alterations of the lattice arrangements).
Preparation
Yellow tungsten trioxide is a finely divided, yellow, crystalline powder. It is produced by roasting ammonium paratungstate at closely controlled temperatures to drive off combined water and ammonia.
Preparation
Tungsten trioxide is obtained as an intermediate in recovery of tungsten from its minerals (See Tungsten). In commerical processes tungstic acid, H2WO4, obtained from the mineral scheelite, may either be decomposed at high temperatures to form trioxide or dissolved in ammonium hydroxide solution and evaporated to yield ammonium paratungstate (APT) crystals, 5 (NH4)2O?12WO3?11H2O. The APT crystals are then washed, dried, and calcined at elevated temperatures to form tungsten trioxideTungsten trioxide, in general, can be made by heating metallic tungsten, its carbides, its lower oxides, or tungstic acid in air.
References
[1]Momeni, Mohamad Mohsen, and Yousef Ghayeb. "Photochemical deposition of platinum on titanium dioxide–tungsten trioxide nanocomposites: an efficient photocatalyst under visible light irradiation." Journal of Materials Science: Materials in Electronics 27.2 (2016): 1062- 1069.
[2]Li, Bin, et al. "Mesoporous Tungsten Trioxide Polyaniline Nanocomposite as an Anode Material for High‐Performance Lithium‐ Ion Batteries."ChemNanoMat 2.4 (2016): 281-289.
[3]Hunge, Y. M., et al. "Photoelectrocatalytic degradation of methyl blue using sprayed WO3 thin films." Journal of Materials Science: Materials in Electronics 27.2 (2016): 1629-1635.
[4]Albalshi, Madleen Ahmad Mohammad. Electrochemical properties of Sol-gel WO3 films Co-doped with Ti and Zn. Diss. 2016.
Hazard
Toxic material.
Flammability and Explosibility
Notclassified
Safety Profile
Moderately toxic by
ingestion. Can react violently with ClF3, Li,
Cl2. See also TUNGSTEN COMPOUNDS.
Check Digit Verification of cas no
The CAS Registry Mumber 1314-35-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,3,1 and 4 respectively; the second part has 2 digits, 3 and 5 respectively.
Calculate Digit Verification of CAS Registry Number 1314-35:
(6*1)+(5*3)+(4*1)+(3*4)+(2*3)+(1*5)=48
48 % 10 = 8
So 1314-35-8 is a valid CAS Registry Number.
InChI:InChI=1/3O.W/rO3W/c1-4(2)3
