Even if you never want to generate hydrogen, [Maciej Nowak’s] video (embedded below) is interesting to watch because of the clever way the electrode is formed from stainless steel washers. You’ll need heat shrink tubing, but you ought to have that hanging around anyway. Building the electrode using the techniques in the video results in a lot of surface area which is important for an electrochemical reaction.
A standard rechargeable cell provides power for the generator which resides in a modified plastic bottle. The overall build looks good even though it is all repurposed material.
