Hunyoung Cho

In volatile solvents virtually all sonication energy is converted to boiling the solvent. Very little is transferred to dispersing the sample or detaching debris from surfaces. Water is the best medium to transfer ultrasonic energy. See (registration required):

Ultrasound, cavitation, and the singing kettle

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W130619UltrasoundCavitationSingingKettle.html

It's better to use C2H6O instead of Acetone. As the ketonic group is more reactive than hydroxyl group, as well as Acetone, has a lower boiling point so it can be easily vaporized by sonication. Furtherly, the solubility of alcohol is higher than ketone.

Alan F Rawle Tariq Bashir

Thanks for the comments!!

Tariq Bashir

Do you know how much time it needs for sonication usually for cleaning?

I'll do sonication for graphene and MoS2 on SiO2/Si substrate. And graphene and MoS2 surfaces are not reactive toward those solvents right?

Article MoS2 cleaning by acetone and UV-ozone: Geological and synthe...

Article Toward Clean and Crackless Transfer of Graphene

Dear Hunyoung,

thank you for posting this very interesting technical question. In general, both graphene and molybdenum disulfide are insoluble in all organic solvents. Thus from a general standpoint you can use any organic solvent for ultrasonic cleaning. However, it is not clear to why you want to clean your CVD graphene and CVD MoS2 and from what? If you followed a proven method to deposit thin films of these materials by CVD, they should be already pretty clean.

For a potentially useful article about cleaning a graphene layer on silica substrates please have a look at the following link:

Ways to eliminate PMMA residues on graphene — superclean graphene

Article Ways to Eliminate PMMA Residues on Graphene —— Superclean Graphene

Unnfortunately I don't have free access to this paper. However, three of the authors have RG profiles and the article is quite recent (2020). Thus you can easily request the full text of this article directly from one of the authors via RG (just in case that it is of interest to you).

For a method to prepare very clean graphene films on silica substrates right away, please also check the following relevent reference:

Direct Metal-Free Chemical Vapor Deposition of Graphene Films on Insulating Substrates for Micro-Supercapacitors with High Volumetric Capacitance

Article Direct Metal‐free Chemical Vapor Deposition of Graphene Film...

This paper is freely available as public full text on RG.

I hope this helps. Good luck with your research and best wishes, Frank Edelmann