I would suggest to make the aqueous sol. Make the buffer is not very far from the IEP, but sufficient to avoid coagulation. In this case during deposition can form a thin oxide layer. On titanium oxide at least I did it.

There is no "best" solvent as this might depend on the substrate you are using. I would go for alcohols as they evaporate fast. It is important that you obtain a stable dispersion of the nanoparticles into the liquid before spin coating. You might need to use a binder as well and a thermal consolidation treatment after spin coating. If you can offer more details about your experiment and aim it will help.

One quick solution is if you are using alcohol. Depending on the spinning rate, the alcohol would evaporate leaving a decent coating. Its better to use sol-gel coating or spray pyrolysis though

I intend to prepare Sno2 nanopartilces using Autoclave. Thereafter I want to deposit a thin films using spin coating. So as per the above suggestions I will dissolve the nanoparticles in a solvent. I beliv methanol will be a good solvent. In case any better suggestion? Now next I do use a microtip to drop a fixed amount of the solution on the substrate. But how do I confirm the adherence? What should be the spinning rate? After the deposition do I need to sinter the film?

Thank you all in advance. Your expertise on the topic will help me a gr8 deal.

Thanks and regards

I would recommend ethanol or IPA instead of the toxic methanol. You need to try a couple of spinning rates but 3000 rpm for 20 seconds could be a start. Usually, you need to sinter the film on the substrate then check its quality using a microscope, etc.

You can check adherence using at the least an adhesive tape method (check for a standard protocol to do this). Check if the film adheres to the adhesive tape or not. Usually, spray pyrolyzed films have good adhesion on glass. As mentioned above, you have to consider the substrate as well in determining the appropriate solvent. Spinning rate can be determined from literature or by experiment (you also need to at least check the literature or do experimental design). Instead of asking if you need to sinter it or not, better to compare the properties of sintered and  not sintered. Then decide which one you prefer (or do structural analysis afterwards).

Before starting up with nanoparticulate films, please consider why you are doing the experiment with reference to the application you seek. If you are looking for the non-stichiometric conducting glasses, the grain boundaries in nanoparticles would scatter a lot of electrons and would not allow you to make highly conducting transparent conducting oxide. If you are looking for a coating for photocatalysis, probably the problem cited above would still be valid. Spray pyrolysis has good adhesion only if carried out at higher temperatures (>400C)......... my recommendation will be to check on your application and then deciding on what you would like to do

Thank you so much for the suggestions. I will definitely give it a shot.

a siple way isby using 1-2 % PVA solution . that will increase adhesion 

use a solvent that wets the substrate. The spining is not the best method to produce homogenous coatings with particles. 

I'm agree. more likely to use dip coating. But if you want block layer I suggest to use CVD or ALD.

i have deposited SnO2 using solvent Ethanol and SnCl2 as precursors formed quikely good quality film using spin coating.

Dear Sandip,

Now I'm also trying to prepare SnO2 film by spin-coating method. Can you tell me have you ever found the right way? Thank you very much.