Copper(I) sulfide

Copper(I) sulfide, also known as cuprous sulfide, is a chemical compound with the formula Cu₂S. It is a black solid that is insoluble in water and is one of the principal ores of copper.

Structure

Copper(I) sulfide crystallizes in a complex structure that is related to the hexagonal close-packed structure. The copper atoms are arranged in a distorted tetrahedral coordination with sulfur atoms. This structure is known as the low chalcocite structure, which is stable at room temperature.

Occurrence

Copper(I) sulfide occurs naturally as the mineral chalcocite. It is an important copper ore and is mined for the extraction of copper metal. Chalcocite is found in hydrothermal veins and in the supergene enriched zones of sulfide mineral deposits.

Preparation

Copper(I) sulfide can be prepared by the direct combination of copper and sulfur:

<math>2 Cu + S \rightarrow Cu_2S</math>

Alternatively, it can be synthesized by the reduction of copper(II) sulfide (CuS) with hydrogen gas:

<math>CuS + H_2 \rightarrow Cu_2S + H_2S</math>

Applications

Copper(I) sulfide is used in the production of copper metal. It is also used in the semiconductor industry for the fabrication of thin films and in photovoltaic cells. Additionally, it has applications in the production of conductive inks and pastes.

Chemical Properties

Copper(I) sulfide is a stable compound that does not react with water. However, it can be oxidized to copper(II) sulfate in the presence of oxygen and moisture:

<math>2 Cu_2S + 3 O_2 \rightarrow 2 Cu_2O + 2 SO_2</math>

Safety

Copper(I) sulfide is considered to be of low toxicity, but it should be handled with care to avoid inhalation of dust or contact with skin and eyes. Proper personal protective equipment should be used when handling this compound.

Also see

• Copper(II) sulfide
• Chalcocite
• Copper extraction techniques
• Sulfide minerals