The key difference between graphite and graphene is that graphite is an allotrope of carbon having a high number of carbon sheets whereas graphene is a single carbon sheet of graphite.
Graphite is a well-known allotrope of carbon. Moreover, we consider it as a semimetal, and it has a layered structure with several layers of carbon that are well-packed on each other. One layer out of these layers is a graphene sheet. A graphene sheet is considered as a nanoparticle according to its dimensions.
CONTENTS
1. Overview and Key Difference
2. What is Graphite
3. What is Graphene
4. Side by Side Comparison – Graphite vs Graphene in Tabular Form
5. Summary
What is Graphite?
Graphite is a stable allotrope of carbon that has a crystalline structure and a form of coal. And we consider it as a native mineral. A native mineral is an element that occurs in nature without combining with any other element. Furthermore, it is the most stable form of carbon that occurs at standard conditions. The only repeating unit of this allotrope is carbon (C). It has a hexagonal crystal system. This allotrope appears in iron-black to steel-gray color, and it has a metallic luster. However, the streak color of this mineral is black (the color which appears in its fine powder).
Figure 01: Graphite
We call the lattice structure of this allotrope as a honeycomb lattice. It has the graphene sheets separated at a 0.335 nm distance. In the lattice structure, the carbon atoms are separated in 0.142 nm distance. The carbon atoms are bonded to each other via covalent bonds, one carbon atom having three covalent bonds around it. Since the valency of carbon is 4, there is a fourth unoccupied electron in each and every carbon atom of this structure. Therefore, it is free to migrate, making graphite electrically conductive. Natural graphite is useful in refractories, batteries, steelmaking, expanded graphite, brake linings, foundry facings and lubricants.
What is Graphene?
Graphene is a single layer out of the multiple layers in graphite. It is a semimetal. This sheet contains a single layer of carbon atoms in a planar structure. Each and every carbon atom has three covalent bonds around them. We call it a hexagonal lattice structure. Unlike graphite, graphene has many uncommon properties. Most importantly, it is the strongest material ever tested. It can efficiently conduct heat and electricity. this compound is nearly transparent.
Figure 02: Graphene Sheet
It has a greater diamagnetism than graphite. Graphene sheets are considered as nanoparticles according to the dimensions (the width of the sheet is in between 1 – 100nm range). The carbon atoms of this sheet have four bonds including three sigma bonds around a carbon atom and one pi bond oriented out of the plane. A major use of these sheets is to produce carbon nanotubes.
What is the Difference Between Graphite and Graphene?
Graphite is a stable allotrope of carbon which has a crystalline structure and a form of coal. It has a high number of carbon sheets. It is brittle. Moreover, carbon atoms of graphite are bonded to each other via covalent bonds, one carbon atom having three covalent bonds around it and there is a free electron. Graphene is a single layer out of the multiple layers in graphite. Unlike graphite, this is a single carbon sheet. In addition, it is the strongest material ever tested. Apart from that, this carbon sheet has four bonds including three sigma bonds around a carbon atom and one pi bond oriented out of the plane. These are the main differences between graphite and graphene.
Summary – Graphite vs Graphene
Graphite and graphene are a very important carbon-containing material that is related to each other. The difference between graphite and graphene is that the graphite is an allotrope of carbon having a high number of carbon sheets whereas the graphene is a single carbon sheet of graphite.
Reference:
1. “Graphite.” Wikipedia, Wikimedia Foundation, 5 July 2018. Available here
2. “Graphene.” Wikipedia, Wikimedia Foundation, 3 July 2018. Available here
Image Courtesy:
1.’Graphite-233436’By Rob Lavinsky (CC BY-SA 3.0) via Commons Wikimedia
2.’Graphene-3D-balls’By Jynto (talk) – Own work (CC0) via Commons Wikimedia
Excellent explanation. Thank you, Madhu.