Sciencemadness Discussion Board

TiO2 Dye Sensitized Solar Cell

Eclectic - 26-4-2007 at 08:47

I ran across this while researching conductive SnO2 films on Titanium:

Rasberry Flavor Solar Cell

Darkblade48 - 26-4-2007 at 10:07

Ah yes, I remember this experiment, my chemistry professor in my first year undergrad chemistry course demonstrated this. He was saying that it would be a good idea for 3rd world countries, as you could coat the entire roof of a house with these to generate electricity. However, apparently, the rasberry does seem to degrade rather quickly, so that's a problem.

12AX7 - 26-4-2007 at 12:45

Seems suspicious that it involves an oxidizer (triiodide), albeit a mild one.

Eclectic - 26-4-2007 at 15:03

Suspicious as in maybe it's more a fuel cell effect than a photocell?

I saw reference to photoelectric effects and semiconductor junctions among the mass of papers on various doped conductive oxides. So while the raspberry flavor cell doesn't look too promising, maybe something along the lines of titanium substrate with doped TiO2 overlaid with doped SnO2?

ChrisWhewell - 28-12-2009 at 10:26

The naysayers have lost again on this one, as Graetzel's cells have now been commercialized. I've recently made an improvement in this area and filed on it. I'm looking at a cell I can make for about $ .50 / watt, but there are a couple engineering issues that need to be ironed out.

argyrium - 29-12-2009 at 11:44

While researching Clitoria ternatea, the attached article came up.



DSCN3640a.jpg - 49kB

Attachment: Ts-3 dye sensitized solar cell using natural dyes extracted from rosella and blue pea flowers.pdf (162kB)
This file has been downloaded 2345 times

ChrisWhewell - 29-12-2009 at 12:07

I havn't yet read the article you provided, but thanks for providing it. this is a great area of opportunity for everyone. Here is a good link from Univ. of Wisc. that offers a kit anyone can buy and get started.

http://www.mrsec.wisc.edu/Edetc/nanolab/TiO2/index.html

Industrious ones will obtain the materials, make a couple cells, and once they've got the hang of things, do just as you've tacitly suggested -- seek out every freakin organic dye you can think of and TRY IT in one of these cells.

I don't know, but suspect, that Nature herself has provided us with an awesome dye in one of her flowers, plants, etc., that just hasn't been discovered yet. The university chemists like Graetzel et al. are great for applying theory to come up with useful things like pyridinyl ruthenium complexes for these cells, but I have a hunch that Nature has hidden a few really good ones that even a layperson can discover.

[Edited on 29-12-2009 by ChrisWhewell]

JohnWW - 29-12-2009 at 12:24

Quote: Originally posted by ChrisWhewell  
(cut) The university chemists like Graetzel et al. are great for applying theory to come up with useful things like pyridinyl ruthenium complexes for these cells, but I have a hunch that Nature has hidden a few really good ones that even a layperson can discover.[Edited on 29-12-2009 by ChrisWhewell]
Ruthenium is much too rare and expensive an element for its complexes to ever be used for large-scale solar electric power generation, certainly on the scale required to replace power from fossil fuels. There must be complexes of much more common transition metals that could substitute for it.

ChrisWhewell - 29-12-2009 at 12:32

Just going from memory which I admit may be faulted, I recall Rh occurs to about 10% of the level of Pt, and that Ru occurs much less than Rh. I also recall that the per troy ounce price of Ru was on the order of about $ 150, although with all the market manipulations that may no longer be the case. In any event if a Ru complex were found best suited and such cells were widely adopted, investing in Ru could provide to be rather wise investment choice.

But I agree with you, that it would be undesirable to involve any metals, since their inclusion is likely not necessary, even though their presence would cause any cells produced useing Ru complexes to not be discarded, rather, recycled.


ChrisWhewell - 29-12-2009 at 12:50

I make the cells according to univ. of wisc., but instead of using TiO2 in mine, I first put a layer of titanium onto glass
using a proprietary technique that generates essentially zero waste:

http://www.genouveau.com/after%20deposition.jpg

and then I fire it, to convert the Ti to its oxide:

http://www.genouveau.com/after%20firing.jpg

Using TiO2 slurries as taught by the prior art is messy, wasteful, and generates materials that need costly disposal, that I like to avoid. Only a thin layer is needed anyhow. This technique provides opportunities because one can patent the process but keep certain later-discovered aspects as trade secrets, making it tougher for others to compete.






[Edited on 29-12-2009 by ChrisWhewell]