Tellurium dioxide Property

Melting point:

733 °C (lit.)

Boiling point:

1245 °C

Density 

5.67 g/mL at 25 °C (lit.)

vapor pressure 

0Pa at 25℃

storage temp. 

no restrictions.

solubility 

insoluble in H2O; soluble in alkaline solutions, acid solutions

form 

Powder

color 

White to slightly yellow

Specific Gravity

5.8

Water Solubility 

insoluble

λmax

360nm(neat)(lit.)

Merck 

14,9123

crystal system

square

Space group

P41212

Lattice constant

a/nm	b/nm	c/nm	α/o	β/o	γ/o	V/nm3
0.48122	0.48122	0.76157	90	90	90	0.1764

Exposure limits

ACGIH: TWA 0.1 mg/m3
NIOSH: IDLH 25 mg/m3; TWA 0.1 mg/m3

Stability:

Stable. Incompatible with strong acids, strong oxidizing agents.

CAS DataBase Reference

7446-07-3(CAS DataBase Reference)

NIST Chemistry Reference

tellurium(IV) dioxide(7446-07-3)

EPA Substance Registry System

Tellurium oxide (TeO2) (7446-07-3)

Safety

Safety Statements 

24/25

RIDADR 

UN 3284 6.1/PG 3

WGK Germany 

2

RTECS 

WY2675000

TSCA 

Yes

HazardClass 

6.1(a)

PackingGroup 

II

HS Code 

28112900

Toxicity

LD50 orally in Rabbit: > 2000 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H317May cause an allergic skin reaction

H332Harmful if inhaled

H411Toxic to aquatic life with long lasting effects

Precautionary statements

P202Do not handle until all safety precautions have been read and understood.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P308+P313IF exposed or concerned: Get medical advice/attention.

Tellurium dioxide Chemical Properties,Usage,Production

Chemical Properties

Heavy, white, crystalline powder; odorless. Soluble in concentrated acids, alkalies; slightly soluble in dilute acids, water.

Physical properties

White crystals; dimorphic; exists in tetragonal and orthorhombic forms; density 5.75 g/cm³ (tetragonal), 6.04 g/cm³ (orthorhombic); melts at 733°C forming a deep yellow liquid; vaporizes at 1,245°C; insoluble in water; soluble in acids and alkalies.

Uses

Tellurium dioxide is used to prepare tellurium metal, telluric acid, and many tellurium salts. It may also be used in the preparation of Ag2Te nanoparticles.

Uses

TeO₂ can be potentially used in medical imaging and industrial monitoring processes.

Uses

Tellurium dioxide is also used in devices which can convert light into sound (acousto-optic material). Glasses made of tellurium oxide have high refractive indices and transmit into mid-IR region. It is used to make glasses with special properties. It is useful in optical waveguides and optical fiber amplification.

Production Methods

Tellurium dioxide in its orthorhombic form occurs in nature as mineral tellurite. It is mined from natural deposits. Also, tellurium dioxide is produced as an intermediate during recovery of tellurium metal from anode slimes of electrolytic copper refining (See Tellurium, Production). The dioxide also is prepared by treating tellurium metal with hot nitric acid to form 2TeO²?HNO³. The product then is heated to drive off nitric acid.

General Description

Tellurium dioxide (TeO₂) is a ceramic material that can be used as a semiconducting oxide. It has a wide band gap and high mobility as determined by density functional theory (DFT) calculations. In bulk quantity, it exists in two polymorphs which include tetragonal α-TeO₂ and orthorhombic β-TeO₂.

Flammability and Explosibility

Non flammable

Safety Profile

Poison by intratracheal route. An experimental teratogen. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of Te. See also TELLURIUM COMPOUNDS.

Purification Methods

Dissolve it in 5M NaOH, filter it and precipitate it by adding 10M HNO3 to the filtrate until the solution is acid to phenolphthalein. After decanting the supernatant, the precipitate is washed five times with distilled water, then dried for 24hours at 110o [Horner & Leonhard J Am Chem Soc 74 3694 1952].