A team of researchers from Stanford University have created a method to produce hydrogen fuel via solar power, electrodes, and seawater from the San Francisco Bay. By using electricity, the researchers have figured out a new way to separate hydrogen and oxygen gas from seawater that does not require costly highly purified water like existing water-splitting methods do.
Their research and methodology is published March 18th in the Proceedings of the National Academy of Sciences.
Hydrogen does not emit carbon dioxide, therefore making it an appealing option for fuel during the current climate crisis. However, using purified water to make enough hydrogen fuel to power cars and cities is not conceivable, according to Stanford’s Hongjie Dai, J.G. Jackson, and co-senior author C.J. Wood.
Splitting hydrogen and oxygen in water — electrolysis — is not a new concept. The process is completed by placing two electrodes in the water. When the power is turned on, hydrogen gas bubbles from the negative end (the cathode), and oxygen is produced at the positive end (the anode). But when electrolysis is done in seawater, the negatively charged chloride corrodes the anode.
But the team realized that by coating the anode in negatively-charged metallic layers (nickel-iron hydroxide over nickel sulfide, all covering a nickel foam core), they could protect the anode, therefore increasing the lifespan of the mechanism from 12 to more than 1,000 hours.
The nickel foam core is the conductor, helping electricity travel form the power source. The nickel-iron hydroxide encourages electrolysis, separating oxygen from hydrogen. And the nickel sulfide transforms into a negatively-charged layer that protects the anode.
The team conducted the majority of their tests in a controlled lab setting. However, they also designed a solar-powered mechanism that ran electrolysis in seawater from San Francisco Bay.
Their simple design will now promote the creation of hydrogen fuel, with the entire process powered by solar and wind energy. And the breathable oxygen can also be used by divers or submarine operators.