MeshPL
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Which lead dioxide anode should I make?
So last time I considered making lead dioxide anode for chlorate cell, but than found a good source of graphite. So I made my cell using graphite
anodes. I paid 1,5$ per 40cm rod with diameter of 1cm.
But recently I discovered that titanium is surprisingly cheap on ebay (I live in a country where ebay is not popular) and thought that I could make a
PbO2 anode with Ti substrate.
I knew that making a succesful graphite substrate anode may be hard, so I decided, that I will do plain graphite for anode previous time.
But right now I have a dilemma, of which pre-coat to use and how shaped substrate should be.
So, as a substrate, I can use rod, sheet with holes or mesh (expanded sheet). At first I thought that I should use a rod which can be easioy rotated
during plating, but it turns out everybody makes such an anodes with plates.
Or should I use graphite rod as a substrate? (Still have 2/3 of a rod remaining)
What considers precoats, it seems that there is doped SnO2 and MnO2 on Co3O4.
Manganese oxide one is somewhat cheaper for me, but so far I haven't found any reports on succesful electrodes with this precoat.
Tin oxide is one, which I know has been used succesfuly, but Sb doping may be slightly expensive (unless very little is needed, like 5 or 10g per
whole electrode). Anybody knows other doping options?
So all in all, which substrate (graphite or titanium), what shape of substrate and which pre-coat should I use?
Also, what is the best temperature for plating PbO2?
I know, this topic has been covered a lot, but well, right now I don't know what to do at all.
[Edited on 31-12-2015 by MeshPL]
[Edited on 31-12-2015 by MeshPL]
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MeshPL
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Hmmm... after some thinking I may try 2 electrodes, both coarsed and preetched titanium rods with Co3O4 precoat one with MnO2 layer in between. I'll
do plating with rotation of electrodes in a temperature about 50C. I won't be doing it for a while, but I'll start gathering supplies.
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MeshPL
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I guess I cannot use alkaline baths for plating alpha lead dioxide since such plating will likely oxidise manganese to KMnO4/K2MnO4. Hmm... what about
Co3O4? It shouldn't be oxidised very easily. Also the idea of cobalt or manganese oxide precoats wasn't well tested before. Should I go for ATO
precoat instead? I'm worried that PbO2 will oxidise MnO2 or Co3O4 to permanganates or Co2O3.
Sorry for triple posting but the I have no ability to edit post that is too old.
[Edited on 15-1-2016 by MeshPL]
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hyfalcon
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Try MMO for your substrate, this has been covered quit extensively before. No need to reinvent the wheel.
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MeshPL
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That will be less fun. I have little acces to MMO-coated anodes. They are not commonly sold here, where I live. Sure, titanium isn't either easy to
get here, but on ebay it is pretty cheap. I could quite easily buy some titanium rods from China for a decent price, most of delivery cost included.
I've looked at possibility of buying DSA anodes, but haven't found THAT good source. But after all it may be worth considering... well, if I had DSA
why would I coat it with PbO2? It's not like I need perchlorates, chlorates are my main goal.
Seems that PbO2 and anodic oxidation won't harm MnO2 too much, except in alkaline enviroment. Co2O3 should be untouched.
Reinventing the wheel is fun.
[Edited on 15-1-2016 by MeshPL]
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hyfalcon
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http://www.ebay.com/itm/MMO-Mesh-Anode-Titanium-Mesh-Cathode...
Industry uses MMO for chlorates. Makes a good substrate for plating PbO2.
Try reading this mans posts here on Science Madness and his blogs here http://www.amateurpyro.com/forums/blog/2/entry-35-lead-dioxi...
[Edited on 15-1-2016 by hyfalcon]
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MeshPL
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Yeah... I've seen it before and assumed it is the best info regarding plating PbO2. I planned to do plating nearly the same way he did, although with
use of different substrate. Maybe I should just buy MMO... I'll have to consider this.
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MeshPL
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Or screw MMO, I'm gonna make PbO2 on Ti with Co3O4 interface layer. I'm not sure, if I should try putting MnO2 between PbO2. I MAY instead try some
other spinel or spinel-like material e.g Co2ZnO4 or Co2PbO4 or Co2MnO4 with various amounts of Co3O4.
I'm OK with failure, Ti substrate can be "recycled", and I can always use Mn(NO3)2 and Co(NO3)2 leftovers (I'm sure I'll have some) to make MnO2 based
electrode.
BTW, PbO2 can be reduced back to PbO in some way?
Edit: Yes it can. I have forgotten about decomposition. But is there a straight
route to nitrate?
[Edited on 19-1-2016 by MeshPL]
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