Thanks for that smack. I forget to look at papers directly when I'm on a phone because a phone is an abysmal platform for looking at complicated things.

I sure hurt my head trying to parse all of that. To be honest my experience with electrolysis principles is not far from being a layperson.

I had some fun generating hydrogen and oxygen gas mixtures for my potato cannon experiments way back in junior HS (somewhere back in the late '80's). I made some really neat observations on my ammeter that lined up with qualitative observations like the fizz rate would drop fairly quickly at the same time as current flow rate.

I could start my electrolysis cell with a good surge of current at the start, but in not very long current would drop quickly. I figured that it was bubble attachment and that seemed to be the problem because a sharp tap to the bottom of my setup would result in a bunch of detached bubbles and a surge of current only to decline again.

I hot glued a motor with a lead fishing weight pinched onto the output shaft to the bottom of the tank (a polypropylene tofu tub) so when I ran the motor it'd vibrate the floor and help shed bubbles. It made a big difference to my gas production.

I've tried to parse my way through that study a couple times and I can't find any reference to actual gas production rates. There is a lot of discussion of improvements to current density vs. voltage which should be a good thing. I am assuming that they are working on the assumption that their current density is going to be their bulk current divided by their exposed electrode area under the assumption that they have no bubbles attached to their electrodes.

This could be a good assumption if the macro observation is that there is never any bubbles stuck to the electrodes. Maybe this is a thing that can be easy to confirm visually.

I have to concede that it would be difficult to come up with a meaningful current per unit area if bubble attachment is an issue because it would be very difficult to measure the area of bubble attachment to calculate actual current per unit area.

It would be far easier to assume no bubble attachment and calculate current per area on that assumption. If the assumption is wrong then one would require higher voltages to drive the same current and that does not appear to be the case, based on their observations that sonicating the bath is reducing the voltage to drive similar current.

My inner dickhead concedes that they are actually achieving a better current flow per unit voltage with their ultrasonic trick, if their results are to be accepted.

Still I would have liked to have seen a gas per power expenditure. Run the electrolysis cell long enough and you'd have a handy checksum accounting of your efficiency improvement to "close the loop" on your voltage and current measurements. Also it would be a bulk observation that the layperson could understand without needing to understand the principles, which a monkey like me would appreciate.

I kind of wish that they crunched their numbers in a way to compare against Gibbs Free energy. I remember a list of chemical reactions that were related to change in enthalpy in HS. I imagine that we are trying to approach an ideal Gibbs Free energy limit so it would be useful to compare improvements in electrolysis in terms of efficiency relative to GFE limits.

I suppose the one thing that is remaining is that I do not know how much power was inputted to their ultrasonic transducer. What was the power required to run their transducer?

Piezo elements aren't very efficient (something like 10% efficient) and liquid mediums tend to eat ultrasonic energy and convert it to heat like mad.

It may be a neat trick to boost output with a sonifier, but it may be that the the effects they're playing with require too much transducer power which negates their 27% efficiency boost.

I remember dumping a bunch of salt into my water bath to increase my rate of gas production. It worked like a charm! I probably quadrupled my gas production rate! I lit a cup of gas mix to celebrate and was treated to a nice loud pop and a kind of funny different flame colour which was immediately intriguing.

Then it hit me as it hit my eyes and lungs: I had ignited a mix of hydrogen and chlorine which was making HCL in my mucous membranes and I just gassed myself...