Introduction: Electrolysis Without Batteries
I did not know this until BlimpEnthusiast told me this in the comments: "Great electrolysis setup! In my electrolyzer I use baking soda as the electrolyte. Watch out for the chlorine gas that comes from the positive electrode when using salt and be in a well-ventilated area." Baking soda produces harmless CO2.
So I now recommend using baking soda instead of salt as the electrolyte.
Step 1: Hydrogen and Oxygen From Water
Electrolysis is the process of using electricity to make chemical changes in a substance. When you pass electricity though water to split the hydrogen and oxygen atoms you are using electrolysis. The electrons passing through the water between the electrodes split the water molecules and the hydrogen atoms travel to the negative electrode and the oxygen atoms travel to the positive electrode. What I do in this Instructable is put a jar over the negative electrode to capture the hydrogen that bubbles up. What I did to make this Instructable unique from the hundreds of other Instructables about electrolysis is that instead of using a battery to power the electrolysis I used a 6 volt wall adaptor. To minimize risk of electrocution I made sure there was a drip loop between the water source and the outlet.
Step 2: Power Source
For the power source I used a wall adaptor that had just 2 separate wires and with a easily identified negative wire. In this instructable the negative wire is the one with the white stripe along the side. Next I cut off the connector so it would no longer be able to to whatever device it was for and then split stripped the ends of each piece if wire no more then a inch. Next I wrapped aluminum foil around the 1 inch long pieces of exposed wire. This is to protect the wires from the water and decaying effects of electrolysis, as well as to make a larger surface area for the electrodes to give them better energy efficiency.
Step 3: Assembly
Next I found a small tray and filled it up with about 2 inches of water. Now I took the positive electrode and put it into the tray off to the side and taped it there with a little scotch tape. Now I got a water bottle lid and cut a small groove in it. This so it can hold the jar up a little bit to make room for the negative electrodes wire and water to have a path from under the jar to the negative electrode. The groove is so it doesn't slip out from under the jar. Next I fill the jar as full as I can with water. After that I put about a tablespoon of salt in the pan and jar. This is because water doesn't conduct electricity well unless it has impurities in it. Now I put the lid on that jar and stick it in upside down in the water. Now keeping the lip of the jar under water I take of the lid. After this I take the water bottle cap and slip it under the jar so there is a crack between the jar and the bottom of the tray. Next I take the negative electrode and slip it under the jar so all of the metal is under the lip. If any is outside of the lip the hydrogen that accumulates there will float up outside of the jar and go into the air where it will turn back into water.
Step 4: Final Steps
Now all you have to do is plug in the adaptor. Make sure there is a drip loop between the pan and the adaptor so that water doesn't reach the outlet. Now all you have to do is wait for the hydrogen to start collecting in the jar. The hydrogen "should" be slightly compressed because it pushing out the water already in the jar but I am not certain. The first picture shows how much hydrogen had collected in a couple hours and the second one shows how much collected overnight. The third picture shows what it looked like when it was full of hydrogen. My electrolysis is not fast or efficient but it uses a outlet instead of a battery like so many others so power and time don't matter very much. I hope you enjoyed this Instructable and and if you improve on it or create a better one please show a picture of it in the comments.
Here is a link to a YouTube video I made of lighting the hydrogen on fire. (The fun part)
http://youtu.be/vU4mNuSb8Gs
Remember to wear eye protection even though it is unlikely "Blow up" or anything major.

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13 Comments
10 years ago
Great electrolysis setup! In my electrolyzer I use baking soda as the electrolyte. Watch out for the chlorine gas that comes from the positive electrode when using salt and be in a well-ventilated area. Baking soda produces harmless CO2
Reply 10 years ago on Introduction
CO2 is quite harmless but it still kills people every day! Search it up before anyone starts to produce it.
Reply 10 years ago on Introduction
Carbon Monoxide or CO kills people because it binds to your blood cells and doesn't let them carry oxygen in your body. The only way Carbon Dioxide CO2 could kill you is if you displaced so much oxygen in the atmosphere you suffocate. But you're going to need a lot more than of a jar of gas for that to happen. CO2 is considered an inert gas so it isn't really toxic. Well, it is no more toxic than clean water is. But you can drown in water. When we exhale we actually breathe out CO2 so the stuff can't be all that bad.
Reply 8 years ago
To correct: 5% CO2 can make hallucinations and 10% can lead to death
Reply 7 years ago
Well yea... But lets say you are in like a 10ft x 10ft room right with roughly what like an 8ft high celing? That is 800 cubic feet... So you would have to produce 40 cubic feet of CO2 to cause hallucinations and 80 cubic feet to lead to death, and some how do it fast enough that the room's ventillation can't handle it.
Frankly I can't fathom a way to achieve this...
Reply 10 years ago on Introduction
Thank you very much for telling me about the chlorine gas I didn't even think of that! I will add your information to the front of the instructable.
3 years ago
Have you tried sodium sulfate? I used that for an electrolysis cell and it worked well. It is easy enough to make with solutions of Epsom Salts (Magnesium Sulfate) and Washing Soda (Sodium Carbonate) in a 1:1 w/w ratio and filtering the resulting magnesium carbonate out with a coffee filter and funnel setup.
The sodium sulfate is should stable and should not produce any gas itself.
7 years ago
Wouldn't you be able to just use a plug that doesn't have a transformer on it? Granted yes I know then you would be mixing high voltage with water and that can go real bad real quick if you aren't careful, but I am reading 180 kiloohms on mine and with the voltage on the line being 120 volts even that really doesn't translate to very many watts. Seems like despite the hazards of working with the high voltage AC you would really get a much faster hydrogen production because the higher voltage will allow much more current through.
Though naturally I can certainly see where a reduced voltage is appealling for safty reasons. Though if you could use a bridge rectifier and capacitor to convert over to DC then even the high voltage set up would be a bit safer. Well... As safe as it gets dealing with such high voltage...
Reply 7 years ago
The problem with that is you need DC current to separate the molecules. The oxygen and hydrogen are each drawn to a positive or negative anode, respectively. With AC current the atoms would be constantly switching which direction they are traveling, which would result in a lot of nothing. I think that is how it would work anyway, haven't done this stuff in years. The rectifier you mentioned should work. All you need is DC with enough voltage and amps to reach the other cathode. If I remember correctly a higher wattage actually speeds up the process, but I didn't do many experiments in that area.
10 years ago
The very best electrolyte for electrolysis is lye, also called drain cleaner or sodium hydroxyde. It is highly caustic, but produces no harmful gasses not even co2. Its what bigger and more professional electrolysis setups use. Its what i use.
Reply 10 years ago on Introduction
Thank you for the info. I might use that the next time I make one. It sounds like there are lots of different substances that will work and some are less harmful or more efficient then the others.
10 years ago
Washing soda works better but baking still works. Really easy to turn baking soda into washing soda in an oven if you can't find any. Just spread it out on a baking sheet and bake at 350 for a few hours.
Reply 10 years ago on Introduction
Thank you I might try one with plain baking soda and one with your washing soda next time and run them side by side. That might be interesting.