Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Is it possible to generate electricity from a pH gradient?
cyentist
Harmless
*




Posts: 4
Registered: 27-8-2019
Member Is Offline


[*] posted on 27-8-2019 at 09:54
Is it possible to generate electricity from a pH gradient?


Is it possible to generate electricity from a pH gradient?

Thanks!
View user's profile View All Posts By User
Steam
Hazard to Others
***




Posts: 223
Registered: 25-3-2014
Location: Minnesota
Member Is Offline

Mood: Triple Point

[*] posted on 27-8-2019 at 15:23


Well technically all pH probes run by measuring a voltage potential across a standard electronde but I think you are asking something a bit more profound. Can a large gradient in hydrogen ion activity drive create a potential.
Try this on for size: electro-osmosis.
https://www.youtube.com/watch?v=zzVa_tX1OiI




DISCLAIMER: The information in this post is provided for general informational purposes only and may not reflect the current law in your jurisdiction. No information contained in this post should be construed as legal advice from the individual author, nor is it intended to be a substitute for legal counsel on any subject matter. No reader of this post should act or refrain from acting on the basis of any information included in, or accessible through, this post without seeking the appropriate legal or other professional advice on the particular facts and circumstances at issue from a lawyer licensed in the recipient’s state, country or other appropriate licensing jurisdiction.
View user's profile Visit user's homepage View All Posts By User
Sulaiman
International Hazard
*****




Posts: 2723
Registered: 8-2-2015
Location: Walsall UK but on extended Holiday in Malaysia
Member Is Offline


[*] posted on 27-8-2019 at 20:06


Quote: Originally posted by cyentist  
Is it possible to generate electricity from a pH gradient?

Thanks!


Yes, if aqueous redox is involved.

Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference)




CAUTION : Hobby Chemist, not Professional or even Amateur
(suffering from separation of me and my chemistry stuff)
View user's profile View All Posts By User
cyentist
Harmless
*




Posts: 4
Registered: 27-8-2019
Member Is Offline


[*] posted on 29-8-2019 at 11:25


Quote: Originally posted by Sulaiman  
Quote: Originally posted by cyentist  
Is it possible to generate electricity from a pH gradient?

Thanks!


Yes, if aqueous redox is involved.

Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference)


You mean I need to have a material that will be oxidised and another material that will be reduced?

Isn't it possible to generate electricity from two solutions of HCl with different concentration just by connecting them with a wire?
View user's profile View All Posts By User
Carbon8
Harmless
*




Posts: 31
Registered: 1-1-2018
Member Is Offline

Mood: No Mood

[*] posted on 29-8-2019 at 13:49


As you mention, you might be able to generate electricity from a concentration cell with an acid (or base) having two different concentrations in the two arms of the cell, but a better example would be a "neutralization cell."

Here are two recent (but gated) examples:

Acid–base machines: electrical work from neutralization reactions
https://pubs.rsc.org/en/content/articlelanding/2017/cp/c7cp0...

Reverse Electrodialysis Chemical Cell for Energy Harvesting from Controlled Acid–Base Neutralization
https://pubs.acs.org/doi/10.1021/acs.est.8b06361

I have also attached a description of a simple neutralization cell.





Attachment: electricity from neutralization.pdf (1.3MB)
This file has been downloaded 26 times
View user's profile View All Posts By User
Sulaiman
International Hazard
*****




Posts: 2723
Registered: 8-2-2015
Location: Walsall UK but on extended Holiday in Malaysia
Member Is Offline


[*] posted on 29-8-2019 at 17:01


Quote: Originally posted by cyentist  
Quote: Originally posted by Sulaiman  
Quote: Originally posted by cyentist  
Is it possible to generate electricity from a pH gradient?

Thanks!


Yes, if aqueous redox is involved.

Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference)


You mean I need to have a material that will be oxidised and another material that will be reduced?

Isn't it possible to generate electricity from two solutions of HCl with different concentration just by connecting them with a wire?


In this case it is the acid/base/water that take part in the redox,
not the metal, which is just a collector or source of electrons.
That's why I said it should be an aqueous environment.




CAUTION : Hobby Chemist, not Professional or even Amateur
(suffering from separation of me and my chemistry stuff)
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 1851
Registered: 20-4-2005
Location: Netherlands
Member Is Offline

Mood: Mood

[*] posted on 30-8-2019 at 04:17


If you have a semi-permeable membrane it is easy. Bacteria and mitochondria reach 180 mV over their membranes all the time.

They actually use it to transform energy from metabolism (ATPases) to other needs (import/export solubles).

https://en.wikipedia.org/wiki/Membrane_potential
View user's profile View All Posts By User
cyentist
Harmless
*




Posts: 4
Registered: 27-8-2019
Member Is Offline


[*] posted on 30-8-2019 at 06:45


Thanks, how can I calculate the voltage generated from a specific pH gradient?
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 1851
Registered: 20-4-2005
Location: Netherlands
Member Is Offline

Mood: Mood

[*] posted on 30-8-2019 at 06:58


Look for the Nernst equation. It is how pH meters work.
View user's profile View All Posts By User
cyentist
Harmless
*




Posts: 4
Registered: 27-8-2019
Member Is Offline


[*] posted on 30-8-2019 at 12:44


This converts pH to voltage: https://www.traditionaloven.com/conversions_of_measures/ph-v...

However, even the maximum pH difference of 14, gives only 400mV.

Can anyone explain please?
View user's profile View All Posts By User
phlogiston
International Hazard
*****




Posts: 1291
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline

Mood: pyrophoric

[*] posted on 30-8-2019 at 14:27


Probably not quite what you were after with your question, but interesting to mentioning in this context: a pH gradient lies at the heart of energy 'production' that takes place in the mitochondria of eukaryotic cells. Fuels are burned to pump protons across the inner fosfolipid membrane of mitochondria, establishing a pH gradient as an intermediate store of energy. Subsequently, the flow of protons back across the membrane drives the production of an energetic molecule (ATP) that is utilised to power many biological processes, including the contraction of muscles.

So, the electrical energy provided to the light on your bicycle, powered by the dynamo attached to your bicycle wheel, once existed as a pH gradient across the inner membrane of the mitochondria in your muscles.

Therefore, 'yes', it is possible.

[Edited on 30-8-2019 by phlogiston]




-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
View user's profile View All Posts By User
VSEPR_VOID
International Hazard
*****




Posts: 717
Registered: 1-9-2017
Member Is Offline

Mood: Fullerenes

[*] posted on 31-8-2019 at 16:00


It exists in the body of every organism with mitochondria
Molecules are broken down to basiclly accumulate a gradient of protons which are used to power proteins by that osmonic pressure I think
https://en.wikipedia.org/wiki/Proton_pump




Within cells interlinked
Within cells interlinked
Within cells interlinked
View user's profile View All Posts By User

  Go To Top