Melbourne researchers say it may only be a matter of years before the artificial leaf is fuelling every community, house and car on the planet.
The machine they have designed relies on a so-far largely untapped fuel source — hydrogen — and draws heavily on the plant process of photosynthesis, in which a plant converts sunlight into energy.
“We have to learn as much as we can from photosynthesis, which is what goes on in leafy plants, because that’s where most of our energy comes from in terms of fossil fuels or current kinds of carbon materials that we use either as food or fuel,” said Professor Doug MacFarlane from Monash University’s School of Chemistry.
Photosynthesis is nature’s most efficient way to make fuel.
“If we can learn what plants do with sunlight and use it to make carbon compounds, then we can potentially make artificially produced fuels for all of the reasons we need fuels currently,” Professor MacFarlane said.
Over the years, other researchers have used a variety of metals as an artificial catalyst for the process, but many were rare and expensive.
By using nickel as the catalyst, Professor MacFarlane and his colleagues have been able separate hydrogen from water at a reasonable cost.
“Obviously the devices we’re talking about are expensive to build and install,” he said.
“So the efficiency in terms of producing fuel that it achieves has to be fairly high to make it worthwhile.”
Success would herald ‘energy revolution’
In this field of study, the process is considered to be practically efficient if 10 per cent of the solar energy used is captured as hydrogen, but the researchers have gone well beyond that.
In earlier tests they recorded 18 per cent efficiency. Now, they have reached 22.4 per cent.
“There are many catalysts that are considerably more sophisticated than nickel and often involving obscure and expensive precious metals,” Professor MacFarlane said.
“So nickel is a rather ordinary catalyst in many respects expect for one thing, which is that it’s cheap. It’s an inexpensive metal and … it produces a very, very stable action in its water electrolysis cell.
“So it’s an ideal choice purely and simply because of the cost.”
The researchers believe the technology could be ready to use in homes within a few years and shortly after that in fuel stations.
It cannot come soon enough for the Australian National University’s Professor Thomas Faunce, who has convened two global conferences on artificial photosynthesis.
He argues success in this field will herald an energy revolution.
“If we can convert all the human-made structures on the surface of the Earth, every road and house and bridge into a structure that does photosynthesis better than plants, then we can take the pressure off nature and we can have distributed food and fuel across the planet,” Professor Faunce said.
The medical and science specialist is trying to establish a global project on artificial photosynthesis, like the human genome project, the Hubble Telescope and the Large Hadron Collider.
Challenge to replace old way of doing business
Professor Faunce argues such global cooperation could deliver the key to dealing with major climate change and the energy security problems facing the world’s population.
But he also foresees some obstacles.
“The carbon-intensive industries like coal and oil are making vast profits from the infrastructure that they have in place,” he said.
“They will be looking askance at this technology and thinking well is it something we can profit from or is it something that’s going to inhibit our profits.”
Professor Faunce had some advice for would-be competitors.
“Look at it carefully because this is something that if you invest in now would actually earn you vast profits, because think of what you could earn if the process had to go on of retro-engineering artificial photosynthesis and to all the structures on the surface of the Earth,” he said.
“There’s vast amounts of money made for the corporation prepared to take this challenge.”
The research is published in the journal Energy & Environmental Science.
Read the article at the ABC.