Dear Ram,

Graphene QDs consist of few layers of graphene and its functional group. actually the lattice distance is about 0.24 nm for Graphene QDs. It has sp2 hybridization,  like a small flake of Graphene.

For Carbon QDs the lattice distance is longer about 0.34 nm which is similar to crystal structure of graphite. Carbon QDs is amorphous and mostly sp3 hybridized.

Ram:

Graphene is a strictly two dimensional material. A single layer of carbon atoms sharing sp2 hybrid bonding. Carbon quantum dots are three dimensional objects sharing sp3 hybrid bonds. Quantum dots are generally not simply agglomerations of atoms.

Graphene is an extended solid (well, sheet) while quantum dots are simply super small clusters of atoms. Quantum dots are given the name because they are so small and the number of atoms are so few that the entire particle can exhibit certain quantum properties.

Since the bonding is different between the two materials, you can use any one of a number of different spectroscopic techniques to tell one from the other, e.g., FTIR. I'd say it's pretty tough to get a piece of graphene on the scale of a quantum dot. I would think it would collapse into a quantum dot (lower energy there for sure). It's really only stable in relatively extended sheets.

If you have one of those new fancy hi-res TEMs, you can actually see the difference. If you have a good X-ray diffraction instrument you might also pick up the very slight difference in bond length. The bonds have different strength after all. And that means the lattice constant is not exactly identical.

Ram, I hope this helps!

Pat

Dear Ram,

Graphene QDs consist of few layers of graphene and its functional group. actually the lattice distance is about 0.24 nm for Graphene QDs. It has sp2 hybridization,  like a small flake of Graphene.

For Carbon QDs the lattice distance is longer about 0.34 nm which is similar to crystal structure of graphite. Carbon QDs is amorphous and mostly sp3 hybridized.

I recommend you to read this articel.

Hope this will help you.

Good luck.

Article Glowing Graphene Quantum Dots and Carbon Dots: Properties, S...

    The main differences between graphene and carbon quantum dots are size and  morphology . Carbon dots are spherical or semispherical carbon particles with a size less than 10 nm while graphene quantum dots is a two dimensional material  of mono-few layers of graphene in the size range of 2- 20 nm. Theoretically, the interlayer spacing ~ 3.35 Å for graphene layer-to-layer.

thank you dear professors for your suggestions and recommendations..i hope gained some ideas about these two carbon based materials.

Information:

" Quantum dots "- Quantum dots are below 10 nm in size and Zero dimensional. Basically, it belongs to semiconductor family.

What are Carbon Quantum Dots?

Carbon quantum dots (CQDs, C-dots) are small carbon nanoparticles (less than 10 nm in size) belongs to quantum dots family.

Similarity and dissimilarity between graphene quantum dots and carbon quantum dots:-

1. Graphene quantum dots (GQDs) and carbon dots (C-Dots) both are in zero dimensional (0-D).

2. Graphene Quantum Dots (GQDs) are also one kind of Carbon Dots. The major difference is the precursors for synthesis of these materials are different.

3. In case of GQDs, the precursor are Graphene based materials.

4. Any kind of carbon materials in nano size, having between 1-10 nm called as C-dots.

5. GQDs are crystalline whereas C-dots are amorphous.

Technically: XRD and Raman analysis suggests the difference between GQD and CQD.

Hope this information will help you/readers.

Thanks & Regards

Mr. Mondal