

UNSW scientists have developed an efficient oxygen-producing electrode for splitting water that can be scaled up to produce hydrogen – a clean energy fuel.


An artist's impression of the water splitting electrode







Unlike other water electrolysers that use precious metals as catalysts, the new UNSW electrode is made entirely from two non-precious and abundant metals – nickel and iron.

Commercially available nickel foam, which has holes in it about 200 micrometres across, or twice the diameter of a human hair, is electroplated with a highly active nickel-iron catalyst, which reduces the amount of costly electricity needed for the water-splitting to occur.

This ultra-thin layer of a nickel–iron composite also has tiny pores in it, about 50 nanometres across.


Nickel foam

“The three-dimensional architecture of the electrode means it has an enormous surface area on which the oxygen evolution reaction can occur,” says Associate Professor Zhao.

“The larger bubbles of oxygen can escape easily through the big holes in the foam.  As well, the smaller holes make the electrode surface ‘wetter’, so the bubbles do not stick to it, which is a common problem that makes electrodes less efficient.”



“I think this electrode has great potential for the industrial-scale production of hydrogen. Our next goal is to understand the science behind it and to further improve its performance.  Cleaner sources of fuel like hydrogen will be particularly important for reducing carbon dioxide emissions and solving the air pollution problems from the burning of fossil fuels such as coal,” says Associate Professor Zhao.