Dear Ganesh,

As far as i know, the cathode will be reduced so its surface will remain active while the anode will be oxidized leading to change in its construction at the surface by forming an oxide layer which is more or less insulating or at the best of very low conductivity leading to decreasing the current up to complete interruption of the current. So, the anodes are composed from noble metals such as platinum to prevent their oxidation.

while the cathode can be composed from oxidizable metals such as copper or silicon. You can get this easily when you form a cell to analyse the water. While you can use many metals for the cathodes you have to use only noble metals for the anode.

So the charge transfer rate depends on the solid - electrolyte interface. If you coat the anode with metal oxide it will not get oxidized but you slowed down the charge transfer rate as you increased the resistance in path of holes to the surface to react with electrons coming to the anode.

Best wishes

Dear Dr. Ganesh Kesavan,

I hope that the following paper can help you in your research:

-Kinetic Study of Redox Probes on Glassy Carbon Electrode Functionalized by 4-nitrobenzene Diazonium

Richard William and Evrard David and Gros Pierre

International Journal of Electrochemical Science, vol.14 (1), 453-469 (2019)

Available at: https://oatao.univ-toulouse.fr/21727/

and at: http://www.electrochemsci.org/papers/vol14/140100453.pdf

Best regards, Pierluigi Traverso

Pierluigi Traverso Thanks a lot sir. I have read this paper before. My results contradict with these results. I am getting FeCN as mentioned in this paper but vice versa in Ru(bpy)2+. If you are interested I can share the image with you. Thanks again, sir. Much appreciated.

https://www.nature.com/articles/s41467-017-02291-9

Dear Ganesh Kesavan

When the surface is modified with metal oxide nanoparticle and you get high integrity barrier behaving like bulky layer leading the redox reaction to be found only at the outer surface which in turn reduce the electron transfer from the faradaic reaction of the redox species. Now, if the modification by metal oxide nanoparticle resulting in less integrity barrier with higher effective surface area then the redox reaction is found to occur not only at the outer surface but also at the interior surfaces which increase the electron transfer from the faradaic reaction of the redox species. This means that the methodology of modification is the rate determining factor for the final performance.

Best regards

Dai, Kehua, Jinpeng Wu, Zengqing Zhuo, Qinghao Li, Shawn Sallis, Jing Mao, Guo Ai et al. "High reversibility of lattice oxygen redox quantified by direct bulk probes of both anionic and cationic redox reactions." Joule 3, no. 2 (2019): 518-541.

Tam, Tsz Kin, Marcos Pita, Mikhail Motornov, Ihor Tokarev, Sergiy Minko, and Evgeny Katz. "Modified electrodes with switchable selectivity for cationic and anionic redox species." Electroanalysis: An International Journal Devoted to Fundamental and Practical Aspects of Electroanalysis 22, no. 1 (2010): 35-40.

@ Mohammed Hussein j. H. Al'Atia Thanks a lot professor. I have varied the concentration on the electrode. I am getting little current variation. I have repeated the experiment twice I am getting the same. Bit confused and don't know how to correlate these results. If you are interested I can share the results with you professor.

Dear Ganesh,

As far as i know, the cathode will be reduced so its surface will remain active while the anode will be oxidized leading to change in its construction at the surface by forming an oxide layer which is more or less insulating or at the best of very low conductivity leading to decreasing the current up to complete interruption of the current. So, the anodes are composed from noble metals such as platinum to prevent their oxidation.

while the cathode can be composed from oxidizable metals such as copper or silicon. You can get this easily when you form a cell to analyse the water. While you can use many metals for the cathodes you have to use only noble metals for the anode.

So the charge transfer rate depends on the solid - electrolyte interface. If you coat the anode with metal oxide it will not get oxidized but you slowed down the charge transfer rate as you increased the resistance in path of holes to the surface to react with electrons coming to the anode.

Best wishes

Nice Dear Abdelhalim Zekry

@ Dr Azeez Barzinjy Many thanks professor. I read the article and it is very much helpful for me.