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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: synopsai on June 20, 2021, 05:31:38 PM

Title: Can metals "crystallise" on inert electrodes?
Post by: synopsai on June 20, 2021, 05:31:38 PM

Hi, when you have a galvanic/electrolysis cell that contains an elektrode that is inert such as a C or Pt elektrode. Can metal ions undergo reduction, thus form a layer on top of them?
Or can metal ions only crystallise on top of an elektrode made out of the same material?

For example, when you have an electrolysis cell made up out of an Mn and C electrode submerged in Mn(NO3)2(aq), will these metal ions form a layer on top of the Mn-electrode or the C-electrode?

I hope it's clear? (English is not my native language) :)

Title: Re: Can metals "crystallise" on inert electrodes?
Post by: Borek on June 20, 2021, 05:45:56 PM

In general it is possible to electroplate one metal on another, but as far as I am aware there are no simple rules that will tell which metal keeps well (and deposits well) on which one. You can have problems with a new layer peeling off, with the metal growing in the form of dendrites and only in some places and so on. Results can depend on the bath used and plating conditions.

In some cases additional layer of copper helps - you first electroplate the metal with a thin copper layer, and the electroplate the copper with the final metal you want on the surface.