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remigallard
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New Chlorate Cell
I am finally starting construction of my first (per)chlorate cell. As seen in the picture i have to MMO anodes, there about 24.5cm by 5 cm. The basis
for my cell will be the pvc pipe, which is 4 in thick. My first question is will pvc work for this? Im pretty sure that i remember sweed saying that
it will work, but I'm not sure. Anyways, my idea that the stopper at the far right of the picture will be the bottom of the cell, i do have primer and
cement to hold everything together. From there i can cut the main pvc pipe to the according size it needs to be. The end cap will be on the top,
cemented onto the main pipe and from there the cap can be screwed on and off, i'm hoping this will allow me to have a chlorate anode/cathode set and
a perchlorate anode/cathode set. Okay so now for a few questions. I have two mom sheets, they are obviously not connected together, is there any
feasible way to connect them, like a electro conductive glue or a spot welder, not that i have one of those, I don't really think that either of those
ideas will work so yeah. Next, will i need to trim down the main piece of pvc pipe so that the mmo anode just about reaches the bottom or can there be
some room between the bottom of the cell and the bottom of the anode, and if so how much room? Oh and the cathode is a stainless steel sheet, its just
not pictured. And my power supply is a batter charger that has two settings, 2amps with 12 volts and 4amps with 6volts. Also i will need to cut holes
in the top cap to put the anode, cathode and venting tube, what type of material should i use to hold these in place? Is there some type of ceramic
concrete or something that works best? Any suggestions and help will be greatly appreciated.
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dann2
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Thanks for asking. The Anode is Lead Dioxide. I have just realized that I posted in the wrong thread. Mean to post the picture in 'More on LD
Anodes'.
I think it all the Lead Nitrate I have eaten that may be the problem................
@Remiggalard
Taking one Anode you have 24.5 x 5 by two (sides) giving a total surface area of approx. 245cm^2. If you use the Anode at 100mA per square cm
(lowish current density) that will mean your cell will demand 24 Amps.
The Anodes are far too big for the cell you are building. Half of one of them (or far less) would do.
Some reading here: www.oxidizing.110mb.com
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remigallard
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Thanks for your input dann2. If i were to cut on of the anode in half and have two anodes separated by a cathode in the middle, would that
configuration work or would that still require the same amount of amps? Thats just a question of curiosity on how that works.
If i were to buy this, http://www.ebay.com/itm/5V-40A-DC-Universal-Regulated-Switch... its a 5volts 40 amp dc power supply, would there be any way to connect the two
anode i have? or would i be better off buying a power supply that provides more so around 20 amps? Also if anyone has suggestions on what kind of glue
i can use to seal the cathode, anode and vent tube to the top, I don't want the glue to corrode, or will it?
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dann2
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Polyester resin is good for sealing Anodes and Cathodes.
Each piece of MMO that you have is capable of 'running' 50 amps (a current density of 200mA per square cm).
How big do you want the cell to be? ie. how much Chlorate do you want per day.
The 5 volt 40 amp supply will work OK. There is nothing wrong with the supply.
Don't use one cathode and two anodes, use one anode and two cathodes.
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gregkdc1
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Just a few more "thoughts" on anodes. I have read this thread in its entirety as well as the PbO2 thread and Dann's site. One area I haven't seen to
much discussion on is manganese dioxide anodes for perch production. I saw that Xenoid did some work in this area and had some limited success in
particular when doping the MnO2 with Bi. There is a patent out there that discusses this and I think it was where he was getting his information.
Anyway that same patent discusses using ethyl silicate to deposit up to 20% of the oxide layer with SiO2 and claims to substantially increase the
life of the anode. Now this raises a few questions for me.
First, do you have to control the Ph in a cell that has SiO2 in the oxide layer? I ask because isn't SiO2 reactive in strong alkali solution forming
silicates?
Also if the SiO2 does get dissolved in a high ph solution does this open up the door to possibly using a silicon anode? I was under the impression
that you can't use silicon because the SiO2 that is formed passivates the anode, but this should be converted into soluble Na2SiO3 in a high Ph
solution.
Has anybody ever tried making an anode with SiO2 and Bi combined in the MnO2 layer?
Last if SiO2 proves to be impractical could you replace it with TiO2 using nitrate decomposition? Ti(NO3)4 may be easier to come by than the ethyl
silicate; however I am having a hard time finding any information about Ti(NO3)4 because of all the idiots that don’t know the difference between
nitrate and nitride.
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Xenoid
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Quote: Originally posted by gregkdc1  | One area I haven't seen to much discussion on is manganese dioxide anodes for perch production. I saw that Xenoid did some work in this area and had
some limited success in particular when doping the MnO2 with Bi. There is a patent out there that discusses this and I think it was where he was
getting his information.
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Hi gregkdc1, it's a long time since I did anything with anodes. But yes, I do recall producing perchlorate with MnO2 and I recall posting the
information on the forum somewhere. I can't remember the details as to whether it was doped with anything, (just found some notes, they say it was
pure MnO2) but I do recall it was thermally deposited over MMO (an old swimming pool chlorinator). Depositing on MMO is a good approach as it provides
a very stable adhesive base. I think dann2 has tried this approach as well.
By the way, when trying to make perchlorate always use sodium chlorate as the starting material, and produce the KClO4 by double dissolution with KCl.
It is way too inefficient using KClO3.
I did actually start a comparative study of solid Pt, plated Pt, and MnO2 coated MMO anodes of roughly the same size, however the logistics became too
difficult, and I realized I could not find a simple quantitative analytical method for perchlorate. In addition I used KClO3 and this produced very
poor results!
One of the problems with trying different perchlorate anodes and doping MnO2, as mentioned above, is comparing the results. I think I came to the
conclusion that a perchlorate specific ion electrode was the way to go for analysis, but they are very expensive.
I now have a large solid Pt anode  which I made from an "old" Pt crucible. It
makes perchlorate at an incredible rate, much faster and more efficiently than a Pt plated Ti anode.
Edit: Found the relevant posts here at the bottom of page 12 in the Technochemistry: Multilayer Metal Oxide / Titanium Anodes for Chlorate/Perchlorate
thread.
"Some notes on MMO/MnO2 anodes from a while back!"
http://www.sciencemadness.org/talk/viewthread.php?tid=9783&a...
Looks like I did try doping with Bi and Co but I didn't fully evaluate their relative performance, mainly because I was messing around with KClO3
rather than NaClO3 most of the time, therefor the efficiency would have been poor for any type of perchlorate anode.
[Edited on 24-12-2011 by Xenoid]
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gregkdc1
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My thoughts are this.
> It is known that MnO2 will make perchlorate but wear rates are high so it is never taken seriously, why not work on methods to increase the
lifespan of the anode?
> This patent claims that doping up to 20% of the oxide layer with SiO2 will greatly increase the life span of the anode. I question how long SiO2
will last in a high Ph solution and I think TiO2 may be a better alternative if the oxide layer remains conductive and structurally sound . http://www.wikipatents.com/US-Patent-4072586/manganese-dioxi...
> Here is some of your previous work concerning MnO2 anodes with Bi dopant go down to the last experiment on the page. The Bi doped anode seems to
be the anode with the best results for perchlorate? http://oxidizing.110mb.com/chlorate/xenoid_mn.html
>Last I wonder what would happen if you doped a MnO2 anode with a combination of Bi2O3 with SiO2 or TiO2, would you get the best of both worlds? A
long anode life that can reliably make perchlorate?
It is good that you have a good anode, but the price of platinum precludes me from buying such an anode. That is a nice find! 
[Edited on 24-12-2011 by gregkdc1]
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michael faraday
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I recently purchases a power supply, a 5volt 40 amp power supply. Where do i buy the clips that will attach the power cord that is attached to the
wall to the power supply itself, the same goes for clips that will attach the cord that will go to my electrochemical cell??
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dann2
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Hello Folks,
@Xenoid.
How do you attach an electrical connection to the Pt crucible?
I presume you flattened it out into some sort of sheet.
You can actually attach a piece of Grade 1, 2, 3 or 4 Titanium to Platinum (or MMO) by simply bolting the Ti to the Pt (or use a rivet). Unfortunately
grade 1, 2, 3, 4 bolts will be almost impossible to find and Grade 5, which contains some Aluminium, will corrode away so you are stuck with the
homemade rivet method.
A dude did this over on AmateurPyro and it works OK even though the connection was submerged in the electrolyte.
It's easy enough to track Perchlorate production by simply keeping an eye on Chlorate destruction with simple titrations. Titrations sound like one
big pile of work but when you have some liters of solutions (Iron Sulphate and K Permanganate) made up, which will do many titrations, its only take
about 10 minutes to do one titration. It will take less time if you do two at the same time.
@gregkdc1
http://www.oxidizing.110mb.com/chlorate/pyrochlor.html
Try Pyrochlores for Perchlorate if you are looking to do something new.
dANN2
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hissingnoise
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| Quote: | | I recently purchases a power supply, a 5volt 40 amp power supply. Where do i buy the clips that will attach the power cord that is attached to the
wall to the power supply itself, the same goes for clips that will attach the cord that will go to my electrochemical cell? |
I'm not quite sure what you're asking, michael - can you rephrase the question?
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Mailinmypocket
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I think what he means are alligator clips... Those are fairly easy to find at any electronics supply stores like Radioshack and I have even seen them
in automotive supply stores too in the car electronics section sold for use as test leads.
See here:
http://www.radioshack.com/search/index.jsp?kwCatId=&kw=a...
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hissingnoise
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I always used crocodile clips to connect to 7/8" electrodes because they're big-jawed and strong!
If he's having trouble connecting his PS to the mains socket, he should probably go for a name change . . .
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Xenoid
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| Quote: Originally posted by dann2 |
@Xenoid.
How do you attach an electrical connection to the Pt crucible?
I presume you flattened it out into some sort of sheet.
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Hi dann2,
The electrode was made from a "scrap" 15-20 ml. tall form Pt crucible. I used "tinsnips" to cut a spiral 7mm. wide strip around the crucible, starting
at the top rim. Obviously the first few cm. of the cut are tapered and this part was tightly twisted and rolled to provide the "lead in" for the main
part of the electrode.
I cast some epoxy resin around this part using a short length of 6mm. plastic drinking straw as a mold. When I removed the straw (I should have left
it in place) there were lots of bubbles in the epoxy and the surface was rough so I covered it with some glue-lined black heat-shrink tubing. This
part is fitted through the cell lid using some plastic flanges and couple of "O"-rings. There is a tiny amount of leakage up the centre of the twisted
"lead-in" but not enough to cause any problems.
The electrode in the image has an overall length of 24 cm. but the length of Pt is longer as it is spiralled. The weight of the original crucibe was
about 14 g. and it was about 30 mm. wide at the top and 30 mm. deep. I was amazed how long the strip turned out. The electrode weighs about 11 g. as I
did not incorporate the crucible base.
The electrode is probably worth about US$450 at current prices as scrap, given that assay, refining and commission needs to be paid.
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dann2
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She's definitely a beauty!
I often thought that the Platinum-on-Ti-mesh Anodes are very expensive for the amount of Pt that you actually get. But since I have neither purchased
nor used one it's only my perception.
Named?
Dann2
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jpsmith123
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Wow that's a nice anode Xenoid!
(I've often wondered how well epoxy would hold up in a ClO3 or ClO4 cell. Apparently it's ok?)
BTW, has anyone yet tried electrodepositing Bi2O3, just by itself, over MMO (or anything else for that matter)?
I came across a paper (attached) showing that the face-centered-cubic form of Bi2O3...apparently the desirable phase...can be electrodeposited from a
highly alkaline solution.
I also came across another paper describing an experiment where electrodeposited Bi metal (as nano-wires) was heated to 350 degrees C - which
converted it into Bi2O3, also in the desirable form (paper attached).
Attachment: Bi2O3_From_Bi.pdf (502kB)
This file has been downloaded 1891 times
Attachment: Bi2O3_From_Alkaline_Solution.pdf (744kB)
This file has been downloaded 837 times
[Edited on 31-12-2011 by jpsmith123]
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michael faraday
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| Quote: Originally posted by hissingnoise | | Quote: | | I recently purchases a power supply, a 5volt 40 amp power supply. Where do i buy the clips that will attach the power cord that is attached to the
wall to the power supply itself, the same goes for clips that will attach the cord that will go to my electrochemical cell? |
I'm not quite sure what you're asking, michael - can you rephrase the question?
|
I just bought a power supply, this one to be exact, http://www.ebay.com/itm/5V-40A-DC-Universal-Regulated-Switch...
I'm looking for the attachments that connect to it, like the clips that i screw into the connection board. or am i supposed to just tie the wires into
it? does that clear it up?
Never mind, I just attached wires to the ports and that worked fine. If anybody knows though, is there a certain size wire that i need to use to
maximize my power supply, which is 40 amps and 5 volts? Like right now I'm just using thin copper wire that was already attached to my alligator
clips, thats whats attached from the power supply to the electrodes.
[Edited on 2-1-2012 by michael faraday]
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hissingnoise
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As long as their resistance doesn't heat them up, they're fine.
But it's best to have them at least as thick as those on the sec. winding . . .
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hissingnoise
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It appears not to have a thermal cut-out and I may be dense but what the fuck is a 'yawl', y'all?
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hissingnoise
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| Quote: | | The electrode in the image has an overall length of 24 cm. but the length of Pt is longer as it is spiralled. |
Lucky you, Xenoid --- but do you not think it would be a better anode if it were beaten flat and polished (if necessary)?
And it might even be long enough to be halved and used as anode and cathode . . .
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cosmos
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| Quote: Originally posted by dann2 | Hello,
When we are controlling the pH, it is the pH of the bulk solution we are interested in. This is where 'chemical chlorate formation' will take place.
(We get no 'chemical chlorate formation' in the non pH controlled cell, only 'Chlorate made by electricity'.)
This is why, in pH controlled cell, it is best to have either a fairly large Anode/Cathode chamber (plenty of room away from the anode) for the 'bulk
reactions' (chemical Chlorate formation) to take place or to have a second chamber for the 'bulk reactions' to take place.
Dann2 |
Can someone explain this better to me or lead me to a source that explains this? Thanks!
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Pulverulescent
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| Quote: Originally posted by cosmos | | Quote: Originally posted by dann2 | Hello,
When we are controlling the pH, it is the pH of the bulk solution we are interested in. This is where 'chemical chlorate formation' will take place.
(We get no 'chemical chlorate formation' in the non pH controlled cell, only 'Chlorate made by electricity'.)
This is why, in pH controlled cell, it is best to have either a fairly large Anode/Cathode chamber (plenty of room away from the anode) for the 'bulk
reactions' (chemical Chlorate formation) to take place or to have a second chamber for the 'bulk reactions' to take place.
Dann2 |
Can someone explain this better to me or lead me to a source that explains this? Thanks! |
What D2 is saying (in a somewhat (confusing?) roundabout way), is that in the anodic oxidation of chloride to chlorate, losses occur which causes the
electrolyte to become progressively more basic over time!
Lower pH favours chlorate formation!
[edit] Household bleach has a high pH to stabilise the hypochlorite, preventing disproportionation . . .
P
[Edited on 8-1-2012 by Pulverulescent]
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dann2
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roundabout way.........huh 
"
What D2 is saying (in a somewhat (confusing?) roundabout way), is that in the anodic oxidation of chloride to chlorate, losses occur which causes the
electrolyte to become progressively more basic over time!
Lower pH favours chlorate formation! "
NO. Havent said that.
Lower pH favours CHEMICAL chlorate formation. (nice but you must control pH)
If going the high pH route (no pH control) you are STUCK with 'Anodic Chlorate formation'.
The electrolyte becomes more basic because small amount of Chlorine escape from the cell untill pH goes to about 10 and Chlorine can no longer escape.
Read the link.
I am trying to explain what happens in a Chlorate cell and at the same time give some explanation (or definitions) to jargon that appears in the
professional literature.
It is an explanation that will be suited to an amateur and not to a professional specalist chemist working in the industry.
Jargon like
'Chemical Chlorate formation' also called 'autooxidation' which is one of the (so called) 'bulk reactions'.
'Anodic Chlorate formation' also known as 'Making Chlorate by electricity' (this is very undesirable in industry).
See here for some explanation:
http://www.oxidizing.110mb.com/chlorate/reaction.html
If that too simplistic go to the further reading section of the page and have a great read.
If you cannot comprehend the explanation you need to study up on your chem perhaps.
'Free Chlorine' is another piece of jargon that gets thrown around.
On another note regarding the Tin Oxide / Bi Oxide Anode (baked onto Titanium), I cannot get it to work. When I bake the Ti with the precursor
solution I just get passivated Ti.
I have tried Bi Nitrate, Bi Chloride (both home made and purchased). I have used Tin TetraChloride :5H2O and also the anhydrous stuff ( fuming
liquid).
As soon as I add any Bismuth compound to the precursor solution I get a precursor solution that does not work. It's as if Bi is a poison. Don't know
why I cannot get it to work as it has been shown to work both in patents and literature.
I etch with HCl, and intend to switch to Oxalic acid to see if that will make any difference (don't think it will).
I also intend to try adding some Nickle to the Bi/Sn Oxide precursor solution(as shown in a paper I obtained in ref. section) to see it that will
work.
After a few more tries I will be giving it up FOR GOOD.
Dann2
[Edited on 8-1-2012 by dann2]
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Pulverulescent
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| Quote: | If that too simplistic go to the further reading section of the page and have a great read.
If you cannot comprehend the explanation you need to study up on your chem perhaps.
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Yeah, you're right D2, I'm just plain, bog stoopid! 
But, sheeesh man, look on the bright side ─ no one will ever accuse you of being even slightly verbally constipated . . .
P
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jpsmith123
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Hello Dann2,
I've been slowly acquiring some bismuth and tin chemicals and planning to do some experimenting...as soon as my present HV power supply project is
done...and it is now essentially finished. (I had a bunch of potting compound that I had to use before it expired, and I finally did that
yesterday...so I'm cleaning off my bench right now).
Anyway, the bismuth difficulties you're describing seem perplexing and very frustrating. But here's my question: As a practical matter, why not first
try putting the Bi2O3/SnO2 on over MMO and/or over one of your experimental ATO anodes?
In my way of thinking, if, under the "ideal" condition of being an overcoat to something else, it fails to make ClO4 or doesn't adhere or wears away
rapidly or something...then you can forget about it once and for all. If on the other hand it looks promising, then it may be worth further
experimenting.
| Quote: Originally posted by dann2 |
[...]
On another note regarding the Tin Oxide / Bi Oxide Anode (baked onto Titanium), I cannot get it to work. When I bake the Ti with the precursor
solution I just get passivated Ti.
I have tried Bi Nitrate, Bi Chloride (both home made and purchased). I have used Tin TetraChloride :5H2O and also the anhydrous stuff ( fuming
liquid).
As soon as I add any Bismuth compound to the precursor solution I get a precursor solution that does not work. It's as if Bi is a poison. Don't know
why I cannot get it to work as it has been shown to work both in patents and literature.
I etch with HCl, and intend to switch to Oxalic acid to see if that will make any difference (don't think it will).
I also intend to try adding some Nickle to the Bi/Sn Oxide precursor solution(as shown in a paper I obtained in ref. section) to see it that will
work.
After a few more tries I will be giving it up FOR GOOD.
Dann2
[Edited on 8-1-2012 by dann2] |
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dann2
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Hello JP,
Paper attached regarding Tin/Bi Oxide Anode + Nickle thrown in.
I have made some Nickle Nitrate from a pure (AFAIK) Nickle welding rod + Nitric acid which I intent to try.
I was thinking of doing what you said. Use MMO or perhaps a known Tin Oxide / Antimony Oxide precursor to form an anode (on Ti) and then start with
some layers of Tin Oxide / Bi Oxide precursor.
I stuck with just using the Tin/Bi Oxide precursors so far (and just got passivated Ti)
Tin Oxide Anode are rather fickle. If you have not got the Ti SPOTLESSLY cleaned and etched you will not get a coat to form. If you use water to wash
the Ti after etching that is not distilled you will NOT be getting a working coat to form. Found that out the hard way.
Perhaps I need a new clean pot of etching HCl but then again I tried making a Tin Oxide/ Antimony Anode during the failed attempts at trying the Tin
Oxide /Bi Oxide Anodes and it worked OK, so it did not seem to be the etching acid or washing water.
Cobalt or Manganese Dioxide Anode seem to be much easier to make in that regard. Just paint and bake and you are there. They don't last terrible long
(the Cobalt Oxide particularly) in a Perchlorate cell.
Dann2
Attachment: Characterization of Ni_Bi Doped Tin Oxide Electrodes_smaller.pdf (127kB)
This file has been downloaded 877 times
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