Why is graphite a good conductor of electricity?

By:Win Sep 24, 2020
Why is graphite a good conductor of electricity?
Graphite is an allotrope of elemental carbon. Each carbon atom releases an electron, and the free movement of electrons can form conductivity.
Why is graphite a good conductor of electricity?
Metals are generally good conductors. The strongest conductive property is silver, followed by copper>aluminum>iron. The high-voltage electric wire adopts the aluminum wire which is cheaper and less dense. Graphite, the human body, the earth, and aqueous solutions of acids, alkalis, and salts are also conductors, and their conductivity is weaker than that of metals.
Graphite is a mineral, a non-metallic material, and has good electrical conductivity. Graphite is mainly used in the electrical industry such as the manufacture of graphite electrodes, brushes, carbon rods, carbon tubes, batteries, graphite gaskets, telephone parts and television picture tube coatings.So it is a good conductor.
Is graphite a conductor or a semiconductor?
Graphite is a good conductor, not a semiconductor. Natural graphite (flake graphite) and most artificial graphite products (such as carbon brushes, electrodes, crucibles, heat exchanger graphite plates, solid lubricating materials, etc.) are good conductors of heat and electricity. There are many uses in the semiconductor industry (ie, the manufacture of semiconductor materials). However, in some cutting-edge research fields, carbon materials such as carbon nanotubes, carbon molecular sieve membranes, and diamond-like films (most of them have some important semiconductor properties under certain conditions) are classified as graphite materials, but their microstructures are all similar to typical The layered graphite structure is significantly different. Therefore, it is very inaccurate to say that graphite is a semiconductor.
Principle of Graphite Conductivity
In graphite, three of the four electrons in the outermost layer of carbon atoms form covalent bonds with the electrons of other carbon atoms. Each carbon atom has three electrons to form a covalent bond, and the remaining one electron is called a π electron. π electrons move approximately freely in the space between the layers, and the conductivity of graphite mainly depends on these π electrons.
Through chemical methods, the carbon in the graphite becomes a stable element such as carbon dioxide, and the conductivity is weakened. If the graphite is oxidized, the π electrons will form a covalent bond with the electrons of the oxygen atom, so that they can no longer move freely and the conductivity will decrease.