Common misconception of Graphene (Chapter I)

11/21/2024

In 2004, two scientists at the University of Manchester in the UK, Andre Geim and Konstantin Novoselov, successfully peeled graphene from graphite using adhesive tape and studied the integer quantum Hall effect of graphene and the quantum Hall effect at room temperature. The two scientists won the 2010 Nobel Prize in Physics.

Known as the king of new materials, graphene is a two-dimensional crystal composed of single or fewer layers of carbon atoms. The theoretical properties of graphene are very excellent, and it is currently the world's smallest resistivity, highest thermal conductivity, highest electron mobility, and hardest and most flexible material. It has a wide application prospect. Since the connection between graphene and the Nobel Prize, the concept of graphene has been hot, and graphene products have emerged endlessly. After more than ten years of rapid development, the public has gradually recognized and accepted graphene. However, many people often misunderstand the correct judgment of graphene products.

Misconception 1: Graphene is too expensive to use on a large scale.

Graphene used to be called "black gold" because the price of 70 USD per gram gives people a feeling of unattainable. However, with the development of technology in the past ten years, the preparation of graphene has expanded from the original "laboratory tape stripping" and "epitaxial growth" methods to industrial stripping methods, so the preparation cost has decreased rapidly. The average price of graphene is less than 0.15 USD per gram, which continues to decline at an average annual rate of about 10%. Therefore, graphene is no longer expensive, and the basis for mass use has long been available.

In addition, many technicians are first exposed to graphene in universities or scientific research institutes rather than enterprises for scientific research, leading to a high price due to the small purchasing amount. However, the purchasing amount and industrial price are not completely at the same level, so it also causes the inherent impression that graphene is expensive. Therefore, the existing price of graphene is no longer expensive, and with the progress of preparation technology, the price has a large space to explore.

Graphene powder	Strip off the graphite with adhesive tape

Misconception 2: Graphene is transparent. Black is not graphene.

Graphene is divided into single-layer and multilayer graphene. A single graphene layer usually exists as a thin film and is prepared by vapor deposition. Multilayer graphene often exists in powder form, using graphite as a raw material by REDOX or stripping method. People often refer to The transparent graphene film as a single or smaller layer of graphene attached to transparent PET. The light transmittance of single-layer graphene is more than 90%, but with the increase of the number of graphene layers and the change of the form of existence (film or powder), the light transmittance of graphene decreases and even becomes black.

Therefore, transparency is directly related to the form of graphene but cannot be used as a criterion for judging graphene materials. In recent years, there has been a misunderstanding in the market that the transparent one is a real graphene product and the black one is fake. As a result, many products on the market use silver nanowire transparent conductive film to make the transparent heating film to pretend the so-called "real graphene products" make people don't know whether to laugh or cry.

Silver nanowire transparent conducting film	Graphene transparent heating film