Hello,
I thought someone might be interesed in the exact procedure I used to obtain Tin Oxide coating VIA SnCl2
Conductive Tin Oxide coating via Stannous Chloride (SnCl2)
Most Tin Oxide coatings on Ti have been achieved via SnCl4 (Stannic Chloride) which is somewhat difficult to obtain and not very easy to make.
The following scheme works well and uses Stannous Chloride which can easily be made from Tin metal and HCl or purchased.
It is taken from J. Material Sci. Technol., 2010, 26(2), 187-192.
"Active Stainless Steel/SnO2-CeO2 Anodes for Pollutants Oxidation Prepared by Thermal Decomposition."
(The paper is two posts above)
The procedure requires a reflux apparatus which need not be very elaborate. The prodedure from the article is as follows:
The precursor solution of SnO2-CeO2 was prepared by dissolving 4.52g SnCl2:2H2O and
0.09g CeCl3:7H2O in 50ml Ethyl alcohol. Firstly, the solution was stirred at room temperature
for 30 min. Secondly, the solution was heated and refuxed at 80C for 5 h. And then, after
sealing at room temperature for 24 h, the precursor solution was finally formed, which was
light yellow and transparent.
Antimony or other compounds can be substituted for the Ce dopant.
Detailed description
2.5 grams SnCl2:2H20 was dissolved in 15ml Distilled Methylated spirits.
0.52g of a liquid containing 31.8% Sb was added. (The Sb liquid was made from Antimony metal + HCl + H202.)
The solution turned slightly milkey due to the presence of water. (It went clear when reflux started.)
The solution was then stirred for approx. half an hour at room temperature and then refluxed for 5 hours. At the end of reflux the solution was
slightly cloudy.
The solution was put into a stoppered bottle and let sit 24 hours. At this stage it was very slightly yellow and slightly cloudy.
A piece of Grade 1 Ti that had been etched for approx. 2 hours in 12% HCl at 90°C was washed in clean water and dried with a heat gun. The Ti was
then liberaly brushed with the solution and let drip dry for 5 minutes.
The Ti was then shaken to remove excess solution and dried using the heat gun. The Ti was kept moving while the drying was taking place so that
puddles of solution did not form on any areas of the Ti.
This solution application and drying procedure was carried out twice more and the Ti was then baked in an oven at 480°C for approx. 7 minutes.
The Ti received three more coats of solution + bake and then three more coats of solution + bake (9 coats and three bakes total).
The Titanium was a deep blue colour when finished.
It was placed into a Chlorate cell and was still running OK after a week with 4.2 Volts accross the cell at an Anode current density of approx. 70mA
per square cm.
Distilled Vodka (90% Ethanol + 10% water) was also used as the solvent instead of distilled Methylated spirits. When the Antimony liquid was added the
solution went very cloudy with a large precipitation of white Antimony Oxide. The solution was refluxed and most of the cloudyness disappeared. This
solution was also successful at forming conductive ATO coatings on Ti. Anhydrous Ethanol is probably best if you can obtain it.
Would F do as a dopant?
Dann2 |
to iodide (I<sup>-</sup>