Attached I have some pictures of carbon nanotube that I produced with a coldwall CVD tank with ethanol vapour. Vacuum level was 250 pascals (not that low). Hot surface was a graphite plate around 800Cdegrees. catalyst was iron nitrate solution dried on a copper plate.
since I have limited acsess to raman spectroscopy and since I am coming from mechanical engineering, I have limited background at possible chemical reactions of carbon.
Can you please look at the pictures and comment if both of them are CNT's or anything else?
what would you recommend as next steps?
Yes, formation of nanotubes can be seen. However, you must go for Raman spectroscopy for confirmation (before any publication). FESEM is a morphological characterization technique. The chemical nature and physio-chemical attributes cannot be understood from this.
You should go for FESEM analysis and we can see the nanotube formed but I think you keep the growth temperature around 900 degC. For your reference, Go through this paper:
https://doi.org/10.1116/1.1689301
Hi Onur, it seems the first image shows CNT bundles (image where a lot of crystallites are seen)- they look very typical, you can even see they catalyst seeds in the ends, however magnification is still too low. Another two images with "flower like" formations are not super convincing to me, it more looks like fibers than CNT. Very tough to say. You need higher magnification and possibly lower voltage to improve the quality of the image.
Only this pic is not sufficient for CNT conformation. Because some special type of raw biowast raw material also produce this type of sem.
It may be k2co3 also, it dend on raw material and activating agent also perfect temp.
EDX will give you qualitative chemical constituents. This Image alone is not providing enough information to characterize CNT. I will suggest structural and elemental characterization steps will shade some information you are looking. Some good suggestions are already provided above.
Thank you all for the answers, I keep producing new samples in my cold walled tank.
Once I have raman results I will share also.
Dear Sir,
The existence of CNTs can be confirmed via;
1. XRD - based on h k l (002) or 260 at 2θ (0)
2. Raman - can be determine type of CNT : SW or MW
3. TEM - can calculate Id also defect of the CNT
Really, from my experience, I don't think you got carbon nanotubes. Rather, they look like carbon fibers, or even fibers with another composition. Figure 8-Kopya shows bamboo-like structures that could be multi-walled CNTs, but in the other figures what is observed are only fibers, whose composition could be related to the growth materials you have used.
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