Splitting Water with Electricity and Ultrasound

Don't know. You're the man HTRN, let us know how it turns out.

Whats strange about this post ? before I opened the Post I naturally read the Heading and the first thought that entered my head was this has to be from HTRN !!
Lo and behold, my 1st thought was correct !
Hi HTRN; does this answer your question ?

Would sound waves affect splitting water for H2

Sound waves can indeed affect the splitting of water for hydrogen production. High-frequency vibrations, such as those used in the RMIT University research, can enhance the electrolysis process by "frustrating" water molecules and creating more free water molecules that can make contact with catalytic sites on electrodes. This increased contact leads to a more efficient splitting of water into hydrogen and oxygen. Additionally, sound waves can generate hydronium ions and create convection currents that aid in mass transfer, further improving the efficiency of the electrolysis process.

Apparently, ultrasound electrolysis increases hydrogen production; however, its energy efficiency is lower due to the energy required to generate the ultrasound.

https://ui.adsabs.harvard.edu/abs/2025ICHMT.16408980T/abstract

Ultrasound also produces heat, and have they tried to capture this waste heat to improve overall efficiency of the system?

I don't know what hertz you'd be running the Ultrasound at, you need to watch your cavitation so it doesn't tear up your ultrasonic horn like a prop would on a boat.

High heat is used in hydrogen production through methods like thermochemical water splitting and high-temperature steam electrolysis to split water molecules. These processes, which can use heat from concentrated solar power or advanced nuclear reactors, are often more efficient than low-temperature electrolysis. The heat enables the chemical reactions to occur at lower energy costs or with greater efficiency. Thermochemical water splitting

• This process uses high temperatures (500°–2,000°C) to drive a series of chemical reactions that produce hydrogen and oxygen from water.
• The high heat can be generated by concentrating sunlight with mirrors or from the waste heat of nuclear power reactions.
• It is a potential pathway for low or no greenhouse gas emissions, as the chemicals are reused in a closed loop.

High-temperature steam electrolysis (HTSE)

• This method splits water at elevated temperatures (800–1000°C), which accelerates the reaction kinetics and reduces the amount of electricity needed compared to low-temperature electrolysis.
• HTSE can be paired with heat sources like advanced nuclear reactors to produce hydrogen efficiently.
• It requires a heat source, electrodes, an electrolyte, and the electrolyzer membrane, along with a power source.

Using high heat yields the best efficiency...

Another idea is to drive the electrolysis with pulsing electricity, which would have a higher ratio of maximum field strength to average power.

https://www.sciencedirect.com/science/article/pii/S1364032125002576