Hi,

this study might help

Poster Investigation of formaldehyde interaction with carbon nanotu...

Some studies proved that:

The hydrogen-bonding interaction between PEI and MWCNTs was proved by the X-ray photoelectron spectrometer (XPS) characterization, and the formaldehyde-sensing characteristics results revealed that the PEI-MWCNTs nanocomposite film sensor exhibited superior sensing properties than the pure PEI film sensor, with linear response characteristics, fast response, low detection limit (0.6ppm), good reproducibility and selectivity to formaldehyde within 6 ppm. A sensing mechanism model was introduced to understand the chemical reaction between formaldehyde gas molecules and amine functional groups of PEI along with the ultraviolet-visible absorption spectra analysis. This paper shows the great potential for developing sensitive and fast-response formaldehyde gas sensor with a simple spraying fabrication method.

https://ieeexplore.ieee.org/abstract/document/7194749

Therefore, it is logical the same would be happened to your synthesized Nanotube too!

Parisa Ziarati Thanks for your detailed response. Still, there is a question that in the gas and liquid phase the reaction will be the same or different. The paper you have shared has used formaldehyde in gas form whereas in my case it's in liquid form. Could you please elab0rate this point?

Thanks

Dear Muhammad Kashif , your question is very interesting since the interaction of MWCNTs with aqueous formaldehyde is little explored in published literature. However, the one vital research article by Maria P etal., titled " Evaluation of Carbon Nanotubes and Quartz Sand for the Removal of Formaldehyde−(2,4-Dinitrophenylhydrazine) from Aqueous Solutions". contain a bundle of knowledge concern the theoretical consideration and experimental results on the interaction nature. Hope it is helpful . Please any feedback is welcome. Best regards

https://tuceel.isc.tuc.gr/Publications/Journals/A101-IECR-18.pdf

Mohammed Hussein j. H. Al'Atia Thanks for your response. I am attaching one file hopefully that will clarify what I want to do and what information is required.

Dear Muhammad Kashif

The approach of the work by Mohammed M. Rahman etal., was based on electrochemical process on the semiconductor spinel ZnFe2O4 nanorods surface, which behave as electronically excited statessurface. The electrochemical process involves mass transfer and electron transfer process; reduction of oxygen and oxidation of formaldehyde.

Now, MWCNTs is nano semiconductor as well but the aqueous interaction with formaldehyde is structural interaction. This means that rapid mass transfer of formaldehyde molecules across the boundary liquid film formaldehyde occurred, followed by a slower intraparticle diffusion of formaldehyde onto interstitial spaces of entangled tubes MWCNTs until adsorption equilibrium of the system established. During these steps the resistivity of MWCNTs coatings in terms of conductance is vary with time according to the diffusion process steps progress toward equilibrium state. This means that the electrode will dispose per one sensing trial.

Please any feedback is welcome. Best regards

Thanks for your next question and also valuable answers by dear friends and colleagues; Of course in liquid form it would have higher reactions and Kinetic of the reaction has been studied in some papers, kindly put the keywords and check it ( even in google), you can find some well written articles!

Best wishes