Sciencemadness Discussion Board

Platinum coated objects

Inoxia - 5-9-2009 at 15:23

Hi,

Im interested in building a persulphate cell to genrate (hopefully) usable amounts of persulphate. I understand,however, the only suitable material for the electrodes of this are made of platinum.
A search on the internet shows ebay as the only feasable place that sells this metal. On ebay, the only person selling Pt wire is £5 per cm + P+P, and im guessing i would need about 10cm. This is £50! Now i just dont have that kind of money to spend so i am trying for alternatives.
Ebay also lists '50 platinum plated earings' for 99p + P+P. This is FAR cheaper. would this be an alternative to pure Pt wire?
If not can somebody recomend another suitable electrode material. I have UTFSE and all i can find on tis matter is using a Pt electrode, none stating other possible materials.

Formula409 - 5-9-2009 at 18:17

You could most definitely get away with using a platinised titanium anode, whereby only a thin layer of Pt is actually present. This gives you much more 'bang' (surface area) for your buck. They are used in amateur pyrotechnics to make (per)chlorates, so have a look at your favourite pyro supplier, also eBay!

For example: http://www.etltd.co.uk/anodes.html or http://www.ti-shop.com/acatalog/Sheet___Plate_Platinised_Ti_... (I assume you live in/near the UK from your post where you used pounds as a currency).

Would not use the wire as it would be very thin and therefore corrode under ever a few amps.

Here is some info on using graphite and PbO2 for persulfates: http://www.journalarchive.jst.go.jp/jnlpdf.php?cdjournal=bcs... and https://www.sciencemadness.org/whisper/files.php?pid=151483&...

Let us know how you go with your search :)

Formula409.

[Edited on 6-9-2009 by Formula409]

Contrabasso - 6-9-2009 at 03:04

A wire electrode of reasonable length will erode badly at the current connection end. This is due to the resistance of the wire and the small potential dropped along the wire by the currentxresistance.

zed - 9-9-2009 at 20:33

Platinum coins are available on e-bay, and they usually sell at close to spot metal price.

For platinum wire, you will probably have to pay a premium.

Here in the States, persulfates are easy to buy.

arsen - 10-9-2009 at 09:14

On ebay, there's a listing selling Pt wire, very thin, but cheap in term of absolute price. You might want to check it out.

Formula: I was surprised at how expensive the Pt plated Ti on those links... I thought they are cheaper.


And, oh if you only need a small amount I have some Pt wire (rather thick though, 0.508 mm) that I can exchange or sell.
Quote: Originally posted by Inoxia  
Hi,

Im interested in building a persulphate cell to genrate (hopefully) usable amounts of persulphate. I understand,however, the only suitable material for the electrodes of this are made of platinum.
A search on the internet shows ebay as the only feasable place that sells this metal. On ebay, the only person selling Pt wire is £5 per cm + P+P, and im guessing i would need about 10cm. This is £50! Now i just dont have that kind of money to spend so i am trying for alternatives.
Ebay also lists '50 platinum plated earings' for 99p + P+P. This is FAR cheaper. would this be an alternative to pure Pt wire?
If not can somebody recomend another suitable electrode material. I have UTFSE and all i can find on tis matter is using a Pt electrode, none stating other possible materials.