I did my Pham in electrochemistry. We made lots of gas electrodes. The method was to use Tyvek (like in house wrap or rain coat material). It is plastic with very small holes and is ver hydrophobic, so water can’t get through but gases pass right through. We then pained one side with conductive paint. We made gold, silver, and graphite electrodes this way. You just put the membrane over a gas inlet with the conductive coating in the solution. Start the gas pressure low and monitor the current. You want the highest current without seeing any bubbles. That is your optimum reaction rate. The advantage is that it is easy to make large electrodes and Tyvek is cheep!
That a great concept, because the resistance to gas flow through the graphite will be a lot higher than the resistance to gas flow down your hole. So you'll have more or less the same pressure drop through all parts of the graphite - should be very uniform. You might want to try to seal the portion that won't be submerged so you don't lose that portion of your gas.
Cool, so you have a solution for making the gas diffusion electrode ! I don´t have to buy an expensive one. Great !!! Graphite should be plenty because it´s only in contact with an alkaline solution and being a cathode as you said at the other video it should last nearly forever. I think graphite only crumbles as an anode If I remember right. I tried it in the past for making chlorine from NaCl and that was my observation so far. Thanks for your credit anyway :D. I will also make a video to confirm you. And yes that is a good thing no catalyst needed haha. Do you know a method to make a membrane at home ?
A proper membrane is incredibly tricky to make. The cation exchange membranes (probably the easiest to make of the two types) involve making teflon polymer functionalised with sulfonic acid, definitely not something possible to do on a home scale as it requires incredibly dangerous (and very difficult to make or buy) reagents like HF or SO3. I've never found any methods for making proper membranes, I'm afraid they're just way out of reach for home chemistry. Unless you can buy some (I don't think they're too expensive, but I've always had trouble with postage), we'll just have to make do with diaphragms like a clay pot or similar.
Maybe you can use two flower pots one for the cathode one for the anode and in between your H2O2 tank. Not hard to buy the guy wanted to sell me the whole roll at 500€ or so.
Yes that would be great ! The clay pot do you know If glazed ones can be used or do they insulate the electron flow ? I found kitchen ware made from clay but they are not always unglazed. Maybe the glazing can be dremeled off too :D Here these are clay sometimes I see such pots for 1-2€ in the market sometimes with the food. www.traditionalspanishceramics.com/WebRoot/StoreES/Shops/63895784/5275/2F71/EC75/2F7B/47F9/C0A8/2AB8/FDD4/tapas_spanish_pots.jpg
I'm afraid the glazing does block the current, as the liquid can't permeate through it. You'll either need to dremel it off as you said, or buy unglazed pots
You are going to lose a lot of gas that doesn't react. I propose putting a cover over the electrode (like in your initial diagram) & use that to capture the gas that bubbles off & recirculate that.
I have a Question! You showed us a partial phase of synthesizing hydrogen peroxide which is substitute for GDE, right? and The hydrogen peroxide hasn't synthesized in this video, then what is the gas in 8:28 is that HO2- ?
@@김민석-u2x8g I didn't take any steps towards synthesising H2O2 with this electrode in this video, I attempt that in a different video. At 8:28, I'm just running air through the electrode to test its permeability, no electrolysis is involved so HO2- is not generated, it's just acting as an air stone in this case.
@@ScrapScience (O2 + H2O + 2e > OH- + Ho2- ) Is it right in order to make this chemical reaction arise, i have to do electrolysis every second? and keep pumping O2? I'm planning to make energy harvester like MAS(Metal Air Scavenger )that GDE is replaced with your video's Carbon Rod. So i should get OH- in solution.
I mean, that’s the reaction that’s meant to happen. I do have a video on trying to get it to work here: th-cam.com/video/HjO8lv0qJnw/w-d-xo.html However, as I found in that video, the reaction doesn’t seem to proceed on the electrode without a catalyst. I don’t think this electrode is actually viable for reducing atmospheric oxygen I’m afraid.
Cool Idea, man. That can be useful for something different too I guess. Not right sure, but possibly glowing the electrodes while pressing the air through them, could increase porousity a bit more, due to oxidation of some Carbon in the wall. By the way, it also may be a way to impregnate the Carbon rod with Catalyst salts, as it should be possible to press a soltion (e.g. of a Titanium-salt) through them this way too and glow them after that. So you can make the Electrodes that are mentioned in this pdf patentimages.storage.googleapis.com/13/4d/99/dfbb875f401486/WO2010134717A2.pdf
I did my Pham in electrochemistry. We made lots of gas electrodes. The method was to use Tyvek (like in house wrap or rain coat material). It is plastic with very small holes and is ver hydrophobic, so water can’t get through but gases pass right through. We then pained one side with conductive paint. We made gold, silver, and graphite electrodes this way. You just put the membrane over a gas inlet with the conductive coating in the solution. Start the gas pressure low and monitor the current. You want the highest current without seeing any bubbles. That is your optimum reaction rate. The advantage is that it is easy to make large electrodes and Tyvek is cheep!
That a great concept, because the resistance to gas flow through the graphite will be a lot higher than the resistance to gas flow down your hole. So you'll have more or less the same pressure drop through all parts of the graphite - should be very uniform. You might want to try to seal the portion that won't be submerged so you don't lose that portion of your gas.
I think this channel will have 100 fold more subscribers inside 2 years
Love your channel man!
Glad you enjoy it!
You are making great videos! Consider recording reactions with tripod, it greatly rises video quality. peace
Cool, so you have a solution for making the gas diffusion electrode ! I don´t have to buy an expensive one. Great !!! Graphite should be plenty because it´s only in contact with an alkaline solution and being a cathode as you said at the other video it should last nearly forever. I think graphite only crumbles as an anode If I remember right. I tried it in the past for making chlorine from NaCl and that was my observation so far. Thanks for your credit anyway :D. I will also make a video to confirm you. And yes that is a good thing no catalyst needed haha. Do you know a method to make a membrane at home ?
A proper membrane is incredibly tricky to make. The cation exchange membranes (probably the easiest to make of the two types) involve making teflon polymer functionalised with sulfonic acid, definitely not something possible to do on a home scale as it requires incredibly dangerous (and very difficult to make or buy) reagents like HF or SO3. I've never found any methods for making proper membranes, I'm afraid they're just way out of reach for home chemistry.
Unless you can buy some (I don't think they're too expensive, but I've always had trouble with postage), we'll just have to make do with diaphragms like a clay pot or similar.
Maybe you can use two flower pots one for the cathode one for the anode and in between your H2O2 tank. Not hard to buy the guy wanted to sell me the whole roll at 500€ or so.
That's the plan for the setup, hopefully using pots instead of membranes doesn't impact the yield too much
Yes that would be great ! The clay pot do you know If glazed ones can be used or do they insulate the electron flow ? I found kitchen ware made from clay but they are not always unglazed.
Maybe the glazing can be dremeled off too :D
Here these are clay sometimes I see such pots for 1-2€ in the market sometimes with the food. www.traditionalspanishceramics.com/WebRoot/StoreES/Shops/63895784/5275/2F71/EC75/2F7B/47F9/C0A8/2AB8/FDD4/tapas_spanish_pots.jpg
I'm afraid the glazing does block the current, as the liquid can't permeate through it. You'll either need to dremel it off as you said, or buy unglazed pots
You are going to lose a lot of gas that doesn't react. I propose putting a cover over the electrode (like in your initial diagram) & use that to capture the gas that bubbles off & recirculate that.
Hello,
Do You know how can I make gdl on cloth?. Like ones available online?. Thanks
Can you please make Na.
One day I'll get around to it. Eventually I'll probably build a down's cell and make some, but I don't have any plans to do so for a while.
is that 1:24 Chlorine gas right? 6:09 there is oxygen gas! don't we inject oxygen gas into graphite?
Chlorine was just an example to describe my concept. Oxygen gas is what we really wanted to perform reactions with.
I have a Question! You showed us a partial phase of synthesizing hydrogen peroxide which is substitute for GDE, right? and The hydrogen peroxide hasn't synthesized in this video, then what is the gas in 8:28 is that HO2- ?
@@김민석-u2x8g I didn't take any steps towards synthesising H2O2 with this electrode in this video, I attempt that in a different video. At 8:28, I'm just running air through the electrode to test its permeability, no electrolysis is involved so HO2- is not generated, it's just acting as an air stone in this case.
@@ScrapScience (O2 + H2O + 2e > OH- + Ho2- ) Is it right in order to make this chemical reaction arise, i have to do electrolysis every second? and keep pumping O2? I'm planning to make energy harvester like MAS(Metal Air Scavenger )that GDE is replaced with your video's Carbon Rod. So i should get OH- in solution.
I mean, that’s the reaction that’s meant to happen. I do have a video on trying to get it to work here: th-cam.com/video/HjO8lv0qJnw/w-d-xo.html
However, as I found in that video, the reaction doesn’t seem to proceed on the electrode without a catalyst. I don’t think this electrode is actually viable for reducing atmospheric oxygen I’m afraid.
Cool Idea, man. That can be useful for something different too I guess.
Not right sure, but possibly glowing the electrodes while pressing the air through them, could increase porousity a bit more, due to oxidation of some Carbon in the wall. By the way, it also may be a way to impregnate the Carbon rod with Catalyst salts, as it should be possible to press a soltion (e.g. of a Titanium-salt) through them this way too and glow them after that. So you can make the Electrodes that are mentioned in this pdf patentimages.storage.googleapis.com/13/4d/99/dfbb875f401486/WO2010134717A2.pdf