UNSW scientists have developed a cheap and efficient electrode for splitting water which has the potential to be scaled up for industrial production of the clean energy fuel, hydrogen.
The technology is based on an inexpensive, specially coated foam material which lets the bubbles of oxygen escape quickly.
"Our electrode is the most efficient oxygen-producing electrode in alkaline electrolytes reported to date, to the best of our knowledge," UNSW School of Chemistry Associate Professor Chuan Zhao explained.
"It is inexpensive, sturdy and simple to make, and can potentially be scaled up for industrial application of water splitting."
The research, by Zhao and Doctor Xunyu Lu, is published in the journal Nature Communications.
Costly oxygen-producing electrodes are one of the major barriers to the widespread commercial production of hydrogen by electrolysis, where the water is split into hydrogen and oxygen using an electrical current.
Unlike other water electrolysers which use precious metals as catalysts, the 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.
This ultra-thin layer of a nickel-iron composite also has tiny pores in it, about 50 nanometres across.
"The three-dimensional architecture of the electrode means it has an enormous surface area on which the oxygen evolution reaction can occur," Zhao said.
Hydrogen production is a rapidly growing industry, but the majority of hydrogen is still produced using fossils fuels such as natural gas, oil and coal, because this approach is still cheaper than electrolysis, but generates greenhouse gases.
Hydrogen is considered good fuel for powering vehicles and storing electricity generated from renewable energy such as solar.
Demand for the fuel is growing in secondary end-user industries and the increasing use of hydrogen in refinery hydro-processing is fuelling the growth of the hydrogen market for hydrogen fuel cell vehicles, but supply can be unstable given growth in the petroleum refining processes space, a report from US-based Persistence Market Research says.
Demand for hydrogen in petroleum refining has increased significantly over the last few years owing to stringent motor vehicle emissions regulations imposed by various governments, and increasing demand is also coming from hydrogen fuel stations.
The Asia-Pacific is the largest market for hydrogen globally, increasing demand from countries such as India and China
The global hydrogen market volume grew from 232Bcm in 2010 by 3.2% to 255.3 Bcm in 2013, and that rate is increasing by 5.3% per annum, with demand from the Asia-Pacific growing by 6.8% in volume during 2010-13.
Linde Group dominates supply with a 20% share, followed by Air Liquide and Praxair with 18% and 12% shares respectively.
