Graphene vs Graphite: What are the differences?

Introduction

Graphene and graphite are two allotropes of carbon that have distinct properties and applications. While both materials consist of carbon atoms, they have different arrangements and structures, leading to their unique characteristics and uses. Here are the key differences between graphene and graphite:

1. Atomic Structure: Graphene is a single layer of graphite and consists of a hexagonal lattice of carbon atoms. It is a two-dimensional material with an extremely thin and flat structure. On the other hand, graphite is a three-dimensional crystal composed of multiple layers of graphene stacked on top of each other. Each layer in graphite is held together by weak van der Waals forces.

2. Electrical Conductivity: Graphene exhibits exceptional electrical conductivity due to its unique atomic arrangement and the presence of delocalized π-electrons. It is considered one of the best conductive materials, even superior to copper. Conversely, graphite has a lower electrical conductivity compared to graphene due to the presence of strong interlayer interactions that hinder electron mobility between layers.

3. Mechanical Strength: Graphene possesses extraordinary mechanical strength and is one of the strongest materials known, with a tensile strength over 100 times higher than steel. This exceptional strength arises from its tightly packed carbon atoms and strong covalent bonds within the graphene sheet. In contrast, graphite's mechanical properties are not as impressive as graphene, as the weak van der Waals forces between layers make it relatively soft and brittle.

4. Optical Properties: Graphene exhibits unique optical properties, including high transparency in the visible and infrared spectrum. It absorbs only 2.3% of visible light, making it nearly transparent. Furthermore, it can absorb a wide range of photon energies due to its atomic thinness and band structure. In contrast, graphite is opaque and displays typical light-absorbing properties of a layered material.

5. Applications: Graphene has attracted significant attention for its potential applications in various fields. Its excellent electrical conductivity, combined with its mechanical strength and transparency, makes it suitable for applications in electronics, energy storage, sensors, and biomedical devices. On the other hand, graphite finds usage in applications such as lubricants, pencils, electrodes, and as a raw material for the production of graphene.

6. Formation and Availability: Graphene can be obtained by exfoliating graphite through mechanical or chemical methods, but the production of large-area, high-quality graphene remains challenging and costly. On the other hand, graphite is abundant in nature and widely available, making it more accessible and economical for various industrial applications.

In summary, graphene is a single layer of graphite with exceptional electrical conductivity, mechanical strength, and optical properties, making it suitable for a wide range of applications. Graphite, on the other hand, is a three-dimensional crystal composed of stacked layers of graphene, displaying lower electrical conductivity, optical opacity, and softer mechanical properties.