We have SEM (Hitachi S-3400N) in our lab but we could not get clear images for TiO2 nanotubes. We want to know if it is possible to use SEM (Hitachi S-3400N) for imaging TiO2 nanotubes with diameter 10-50 nm? How to prepare the sample? And what are the required settings [accelerator voltage, mode (SE or BSE), etc.]..
I have attached examples for the gotten images of TiO2 nanotubes (TNT1,2) and ZnO nanoflowers (ZNR).
Thanking you in advance.
Whatever the conditions you may use, you are at the resolution limit of the SEM. You can guess the NTs from the pictures, but you'll never get a clear view of them, whatever you do. You have no choice but using TEM instead for such nano-objects.
Alain
I completely agree with Alain, with SEM it is impossible, whatever experimental conditions you use, to clearly identify the nanotubes. TEM is the best technique in these cases.
You should go for FESEM .sem doesn't work due to resolution limits.you can just have an idea whether you have synthesised nano material or not by use of SEM so go for FESEM
FESEM is the first choice for the imaging of nanotubes. We obtained the best results (see attached pic) so far using an in-lense SE detector in low working distance and at low voltage (few kV). However, we also got some lucky shots of some nanotubes (about 100 nm diameter) with a very old SEM with tungsten filament (see second paper attached).
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@ Alain Celzard and Marcella Bini
Your answers are very wrong. Question was not about carbon NT but about TiO2 nanotubes which are much bigger (10-50 nm). This size is good enough for FE SEM (actually FE SEM is not bad even for multiwalled carbon NT).
@ Abdo Hezam
Your microscope is not really capable of observation 10 nm NT, but not bad for 50 nm. However it should be in top-notch condition (and not as seen on pictures you posted).
Thank you All of you
Thank you Vladimir Duesvich
I got 2 publications show images(attached bellow) support Vladimir Duesvich answer but for TiO2 Nanotubes array and ZnO nanowires. They used Hitachi S-3400N which is similar to our SEM instrument . I hope now I will get much better images for my material using our ordinary SEM by following the advises given by researchers in my previous question in which only Vladimir Duesvich told me the right maker of my instrument form images. https://www.researchgate.net/post/Why_are_the_SEM_images_of_my_synthesized_TiO2_nanotubes_and_ZnO_nanorods_not_clear_even_at_1_micro
If I get good images I will let you know
1) http://www.hindawi.com/journals/jnm/2013/297676/
2) J. Zhan L. Z. Liu, L. Yang, Z. X. Gan, X. L. Wu, and Paul K. Chu APPLIED PHYSICS LETTERS 104, 231902 (2014)
You can check how the images can looks like in this paper.
https://www.researchgate.net/publication/273791567_TiO2_nanotube_composite_layers_as_delivery_system_for_ZnO_and_Ag_nanoparticles__An_unexpected_overdose_effect_decreasing_their_antibacterial_efficacy
But it was done with ColdFEG SEM, wich has much better resolution (o,4nm).
On S3400 You can try small beam like 20-30 and long acqusition time like 180-360s.
It can be difficult to allign astigmatism on very weak beam, but in reduced window it is possible.
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