Experimental study of ultrasound-assisted alkaline water electrolysis for hydrogen production

Hydrogen bubble production by ultrasound-assisted alkaline water electrolysis was investigated by analyzing visual images of hydrogen bubble motion with a high-speed camera and controlling on/off times of ultrasound. The hydrogen production experiment was conducted under constant current conditions of 2 A to compare power efficiency based on different on/off times of ultrasound. While ultrasound is turned on, hydrogen bubbles are removed from the cathode surface and the cell voltage reduces as the hydrogen bubble layer thickness becomes thinner. The present experiment demonstrates that ultrasonic agitation can reduce the hydrogen bubble layer thickness and significantly decrease the power required for hydrogen production. The effects of on and off times of ultrasound on hydrogen bubble layer formed on the cathode surface and power efficiency for hydrogen production were quantified.