Оксид вольфрама кобальта (CoWO4)

Description

Cobalt tungsten oxide, cobalt tungstate (Cobalt tungsten oxide, CoWO4), CAS 10101-58-3 - inorganic salt of cobalt(II) tungstic acid. Belongs to the class of complex transition metal oxides.

Basic Attributes

• CAS No.: 10101-58-3
• Chemical Formula: Co,O,W (CoWO4)
• Molecular Weight: 306.77
• Exact weight: 306.864
• EU number: 233-254-8
• DSSTox ID: DTXSID70723592

Physico-chemical characteristics

• PSA Specifications: 80.26
• Appearance: Gray powder
• Density: 8.42 g/cm3
• Melting point: 1280 °C
• Solubility in water: insoluble in water, soluble in hot concentrated acids

Scope of application

Cobalt tungstate is used as a pigment and drier (drying agent) for enamels, paints and inks, a component of electronic devices and anti-knock additives. In catalytic studies, CoWO4 is considered as a catalyst for the oxidation of water and the decomposition of water into elementary components with the transfer of electrons to a sacrificial acceptor, as well as a promising catalyst for hydrogen production and CO2 conversion. In photocatalytic applications, it works by generating electron-hole pairs upon absorption of light, which triggers redox reactions to decompose organic pollutants.

Safety Information

• Hazard class code: 20/21/22-36/37/38
• Safety instructions: 26-36/37/39

Storage and transportation conditions

Store in a tightly closed container in a dry, ventilated area. When working with powder, use respiratory and eye protection due to the irritating effect on the skin, eyes and respiratory tract (code 20/21/22-36/37/38); Avoid dust generation and inhalation.

More about quality control

When accepting batches of CoWO4 for industrial use, the particle size distribution, phase purity by X-ray diffraction and the content of impurity phases of cobalt and tungsten oxides are checked, since the presence of foreign phases significantly reduces the catalytic and pigment efficiency of the material.

Comparison with related tungstates

In the series of transition metal tungstates (MnWO4, NiWO4, CoWO4, FeWO4) with a wolframite structure, the properties change naturally with a change in the metal ion: in CoWO4, the combination of the magnetic properties of cobalt(II) and the electronic structure of the tungstate ion determines the specific color and catalytic activity, which distinguishes it from similar compounds of other 3d metals of the same structural group.

Crystal structure and preparation

Cobalt tungstate crystallizes in a wolframite-type structure, which is characteristic of many double oxides of the formula AWO4 (A is a divalent transition metal), which determines its high thermal and chemical resistance. Industrially, CoWO4 is produced by coprecipitation from solutions of cobalt salts and sodium/ammonium tungstate, followed by calcination of the precipitate, or by solid-phase synthesis from cobalt and tungsten oxides at high temperatures - the choice of method determines the particle size and specific surface area of ​​the powder, which is critical for catalytic and photocatalytic applications.

Exact values ​​according to the original source

For completeness of the reconciliation, we present the numerical values ​​from the original supplier dump in their exact notation: 306.86400, 80.26000.