Rich_Insane
Hazard to Others
Posts: 371
Registered: 24-4-2009
Location: Portland, Oregon
Member Is Offline
Mood: alive
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Dye-Sensitized Cells
Hey guys.
A bit ago I did an experiment (it was sort of school related) with dye-sensitized cells or Gratzel cells based on this paper
Demonstrating Electron Transfer and Nanotechnology:
Dye sensitized solar cells
I received a whole bunch of them from the O Chem prof. who was doing a little research about using porphin dyes, and used them for my experiment which
involved using mushroom-derived melanin dyes.
But really if you want to see something interesting all you need is blackberries (or any dye that will form bonds with TiO2) and an electrolyte. The
blackberry dye (anthocyanins) works by attaching to the TiO2 nanocrystalline surface (the TiO2 is ordered from a European company, Degussa, and is
also labeled P25, indicating the particle size in nm). When it is exposed to UV or Visible light, the electrons in it move up from ground state, get
all excited, and pop out. The electrons move through the TiO2 surface, go through the glass into your wire, and go into your resistor. There is a slab
of conductive glass on the other side. The electrolyte, which is I2/KI in ethylene glycol reduces the dye, and so the cycle continues.
My cell based on mushrooms lasted for a few years, of course replenishing some of the electrolyte which often evaporated. Eventually, I sealed the
whole thing off to avoid evaporation, but it's damn tricky.
I want to sell/trade or even give away these cells, as they are stuck in my food refrigerator, including the electrolyte which has since evaporated,
condensed, and formed a mess, and gotten in my cheese 
Obviously, you'd have to make your own electrolyte and dye, but it is quite simple, and unless you want to power your house, you only need a little
(200 microliters/every few hours at max). I believe I was able to reach 500 millivolt output with my mushroom cell, and others reached enough to power
a small motor (in the paper). A tip is to completely submerge the cell in the filtered dye, which is simply made by crushing blackberries (or whatever
dye you use). Leave it to soak in dye for at least eight hours from personal experience. I grew Portabella mushrooms under 390 nm UV light and
extracted a melanin suspension by crushing the mushroom cap in i-Propyl alcohol while adding a little tap water bit by bit. Then I submerged the TiO2
plate.
I would be happy to provide all the TiO2 and conductive plates I have as well as some conductive glass, and possibly a cell i built before out of
mushroom.
PM me any offer. you don't have to pay for anything, but I would appreciate any offer.
I will give up this ofer and throw away the cells if nothing comes up in a few days, as it is quite a nuisance having them around however small they
are.
[Edited on 10-8-2009 by Rich_Insane]
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