A cheap, emissions-free device that uses a 1.5-volt AAA battery to split water into hydrogen and oxygen by electrolysis has been developed by scientists at Stanford University. Unlike other water splitters that use precious-metal catalysts, the electrodes in the Stanford device are made of inexpensive, abundant nickel and iron.
“This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low,” said Hongjie Dai, a professor of chemistry at Stanford. “It’s quite remarkable, because normally you need expensive metals, like platinum or iridium, to achieve that voltage.” He and his colleagues describe the new device in a study published in the Aug. 22 issue of the journal Nature Communications. Fuel cell technology is essentially water splitting in reverse. A fuel cell combines stored hydrogen gas with oxygen from the air to produce electricity, which powers the car. The only byproduct is water, unlike gasoline combustion, which emits carbon dioxide, a greenhouse gas.