I have performed electrochemical deposition of PEDOT/GO prepared in aq solution containing LiClO4 on nickel foam. But deposition layer does not form on the cleaned nickel foam. FYI, nickel foam was cleaned using HCl, acetone, ethanol and finally in DI. Is there anything wrong in cleaning process? I could able to obtain the deposition layer on unclean nickel foam (used as received)
Cleaning process is not absolutely perfect. You can also perform CV in acid solution, then deposit your desired materials. You have to consider substrate and applied potentials. Active substrate and inactive substrate are not same. Please read these following papers. J. D. Benck, B. A. Pinaud, Y. Gorlin and T. F. Jaramillo, PLoS
One, 2014, 10,1–13, RSC Adv.,2016,6, 74453.
Which method did you use to deposit the PEDOT/GO composite, constant potential or constant current, or cyclic voltammetry? Also, will you be able to upload the I-t, E-t or CV to RG so that I can tell what is happening in your experiment. I cannot imagine too big a difference between your cleaned and uncleaned Ni foams. The HCl cleaning should have removed the surface nickel oxide layer, but the oxide layer can reform once you have exposed the Ni foam in air or placed it in water.
Dear Sir,
The method used to deposit PEDOT/GO is chronoamperometry at potential of 1.2 V (vsAg/AgCl) for 10 min and platinum wire as counter electrode. Here I attached chronoamperogram of PEDOT/GO using both cleaned Nickel foam and uncleaned nickel foam.
Ni foam can be removed using FeCl3 and HCl. This article can help you.
Applied Catalysis B: Environmental 187 (2016) 367–374
1.2 V vs Ag/AgCl may be too positive (too anodic) for nickel which might have undergo anodic dissolution in your aqueous electrolyte of LiClO4. This is indicated by your I-t plot of the cleaned electrode on which the current is 10 times greater than that on the uncleaned electrode. You should be able to notice the electrolyte becoming greenish if a sufficient amount of Ni2+ ion was dissolved into the electrolyte. The uncleaned Ni foam might have an oxide layer that protected the underneath metal from anodic dissolution. This oxide layer may only slow down the anodic dissolution, but not avoid it completely. However, the deposited PEDOT film might have provided an additional protection of the Ni metal from anodic dissolution.
The way to bypass this problem is to use a less positive potential at about 0.9 V vs. Ag/AgCl (anodic dissolution may still occur but would be slower, allowing deposition of the PEDOT film which will in turn to minimise Ni dissolution), or better, to use an organic electrolyte such as acetonitrile with LiClO4 as the supporting salt.
The oxide layer will reform more easily once you expose it in air or in water for a long time. Uncleaned Ni foam itself has a protective layer, so it is not easily oxidized. u should deposite ur material on Ni foam immediately after cleaning the foam.
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