Cadmium Oxide

Cadmium Oxide powder is a fine crystalline or amorphous powder with a high melting point that is usually brownish-red to brownish-black in colour at room temperature, somewhat toxic, insoluble in water and alkali, but soluble in acids and ammonium salts, and is commonly used in electrical, optical and chemical industries.

Properties

Chemical formula and molecular weight: chemical formula is CdO, molecular weight is 128.41g/mol.

Stability: Relatively stable at room temperature, but avoid contact with strong oxidising agents, strong acids, etc., otherwise reactions may occur. For example, contact with oxidising agents (such as chlorate, nitrate, perchlorate or permanganate, etc.) may form compounds with very sensitive explosive properties.

Appearance: usually brownish red to brownish black amorphous powder, also exists in cubic crystal form.

Density: The density of crystalline cadmium oxide is 8.15g/cm³, and the relative density of amorphous material is 6.95g/cm³.

Melting point and boiling point: Melting point is 900-1,000°C (the amorphous form will decompose in this temperature range), boiling point is 1559°C (sublimation will occur at this time).

Solubility: insoluble in water and alkali, soluble in dilute acid, ammonia and ammonium salt solution.

Refractive index: about 2.49.

Conductivity: has a certain degree of conductivity, can be used in the manufacture of some electronic components.

Applications

Pigment field:

In the glass and ceramic industry, cadmium oxide can be used as a pigment, which can present unique colours, such as used in the production of red, yellow and other coloured glass and ceramic products, to increase their decorative and artistic value.
In paints, inks and other coatings, cadmium oxide pigments can provide bright, long-lasting colours with good light and heat resistance.

Electronic industry field:

It can be used in the manufacture of electronic components, such as in varistors (variable resistors), to control current and voltage by using its special electrical properties.
As a material for transparent conductive electrodes, it is used in some electronic display devices, although it is gradually being replaced by other safer materials due to its toxicity and environmental concerns.

Battery field: It is the key component of Ni – Cd batteries, which have high energy density and long service life, and is commonly used in some equipment with high requirements on battery performance, such as emergency lighting equipment, backup power in aerospace equipment, etc.

Electroplating field: It can be used as a component of electroplating solution for cadmium plating, so that the metal surface obtains good corrosion resistance, especially in some industrial environments that require high corrosion resistance, such as marine engineering and chemical equipment.

Catalyst field: it can be used as a catalyst in some chemical reactions, although its catalytic activity is high, but due to toxicity and environmental issues, the application in this field is somewhat limited.

Semiconductor field: it can be used in the preparation of semiconductor materials, especially in some special semiconductor devices, such as in the preparation of mercury cadmium telluride (HgCdTe) semiconductor materials, cadmium oxide can be used as a cadmium source.

Alloy manufacturing field: it can be used in the manufacture of various alloys, such as hard steel alloys, printing alloys, etc. It can improve the performance of alloys, such as improving hardness, strength and corrosion resistance.