The major difference between CNT and graphene lies on the electronic structure. Graphene with perfect honeycomb lattice is a zero-band-gap semiconductor. CNTs show either metallic or semiconducting properties, which depends on their chirality.

Dear Bingxin Yang,

Difference between Graphene and CNT:

1. Graphene:

• A single, 2 dimensional layer of graphite is called graphene. So, graphene is basically a sheet of carbon atoms arranged in a hexagonal layout.
• Graphene, discovered at Manchester University (UK) in 2004, is a single, 2D layer of carbon atoms, tightly packed in a hexagonal lattice structure.
• In simple terms, it is the thinnest, strongest material yet discovered and the most efficient conductor of both heat and electricity currently available.
• Graphene is considered the first 2D material ever discovered, and is also called a ”wonder material” thanks to an enormous group of properties it holds.
• For example, graphene is one of the strongest materials in universe, has superior thermal and optical properties, excellent tensile strength, relative transparency, amazing electrical conductivity, and impermeability to most gases and liquids and more.
• Graphene’s many attributes make it an attractive material for researchers and developers, which are working hard all over the world to find endless uses for the material.
• Graphene’s tial is vast, and the applications include: touchscreens (for LCD or OLED displays), computer chips, batteries. energy generation, supercapacitors, medical equipment, water filters, solar cells and more.

2. Carbon nanotubes:

• Carbon nanotubes (often abbreviated to CNTs) are cylindrically-shaped molecules made of carbon atoms. A sheet of graphene can be rolled-up to make a carbon nanotube.
• A single-wall carbon nanotube (SWCNT) is a tubular structure that can be thought of as a rolled sheet of graphene joined to form a seamless tube. Typically around 1 nm in diameter, a CNT can be millions of times longer.
• CNTs can be single-walled (SWCNT) if made from one layer of carbon atoms, or multi-walled (MWCNT) when consisting of several layers of graphene sheets. In fact, carbon nanotubes come in various diameters, lengths, and functional group content which can tailor their use for specific applications.
• The properties of CNTs change according to their characteristics. For instance, MWCNTs are usually conducting while SWCNTs can be electrically conducting, display the properties of a semiconductor or be non-conducting. Factors like structure, length, surface area, surface charge, size distribution, surface chemistry, and agglomeration state, as well as purity of the samples, have great impact on the properties of carbon nanotubes.
• CNTs have unique mechanical, thermal andelecronic properties that make them intriguing for the development of new materials: impressive mechanical tensile strength,light-weight, good thermal conductivity and much more.
• These properties make carbon nanotubes attractive for electronic devices, sensors and biosensors, transistors, batteries, hydrogen storage cells, electrical-shielding applications and more.
• Carbon Nanotubes have been around since the early 1990s and already found some commercial use in the fields of engineering plastics, polymers, displays, anti corrosion paints, thin films and coatings, transparent and non-transparent conductive electrodes, coatings and anti-static packaging and more. In addition, active research is ongoing in fields like batteries, fuel cells, solar cells, water desalination and more.
• However, after the initial hype, revolutions failed to happen and many gave up on CNTs. But this is not to say that they do not have actual potential and interest in them is reappearing in the research community in the last few years. As was said, they have found some uses and more are estimated to follow and the potential of CNTs is not considered to have been exhausted.
• CNTs are available in bulk quantities up to metric ton quantities. Production capacities for CNTs have been scaled up considerably over the years and currently exceed several thousand tons per year. It is estimated that several CNT manufacturers have over 100 ton per year production capacity for multi walled nanotubes. It seems that the capacity for the production of MWNTs exceeds that of SWNTs, although there is an oversupply in the market. SWNTs are much more expensive and difficult to manufacture than MWCNTs, and there is not yet a distinct large-scale market for SWNTs, which is needed to drive down the production cost.

I hope I have answered your question.

With Best Wishes,

Samir G. Pandya

大兄弟，这是你们的课后作业吗？

Xiao-Long Liu 不是作业 professor让我区学习这方面的东西 但是我读的文章都只说 啊xx的优点有xxx，都没说缺点，但我想知道有哪些缺点