Menu
Scientific Advances
Natural compound speeds bone growth
Astronomers spy massive stars in the making
Frog gene map a leap forward for humans
Sun-shy mums may raise MS risk in babies
Soft fossils provide new target for ET search
Mammoth blood brought back to life
Outdoor exercise can boost self esteem
Athletes on growth hormone 'sprint faster'
Countdown begins to 520 day 'Mars mission'
Warmer planet to stress humans: study
Plasma rocket to shorten space voyages
Vaccine may trigger infant epilepsy onset
'Fingerprinting' points to dusty Australia
The hole in the ozone layer: 25 years on
Humans interbred with Neanderthals: analysis
Herschel shows star formation is slowing
Washing hands makes tough choices easier
'Face-book' to measure pain in mice
Science gives clues to World Cup success
Human sigh acts as a reset button
Expert confirms Phar Lap arsenic theory
Dictionary blunder a matter of gravity
Warning on high-dose vitamin D
Calling mum makes you feel better
Sunlight shines on silver technology
Scientists have taken a promising step toward the goal of generating a new source of clean energy, using little more than sunlight and water.

Dr Zhiguo Yi from the Australian National University (ANU) and collaborators in Australia, China and Japan have proven that a simple chemical based on silver, called silver orthophosphate, can produce gaseous oxygen from water when exposed to visible light.

This breakthrough, published in the journal Nature Materials, raises the possibility that the silver compound could be used to 'split water' into oxygen and hydrogen, allowing the hydrogen to be used as a clean fuel.

Researchers have long hoped that splitting water could be a way to produce clean energy, but so far all the methods they have tried have required large amounts of electricity.

The new technology helps overcomes that problem by allowing sunlight to be used as the energy source.

"With increasing world-wide interest in alternative renewable sources of energy, developing materials that can be used to efficiently convert solar energy to clean energy is a vitally important task," says study co-author Professor Ray Withers of the ANU.
Overcoming instability

Yi came up with the idea of using the silver compound after thinking about the silver halide chemicals that are used to develop photographs. Photographic developing has to be done in the dark because these chemicals break down in sunlight.

"It is well known that compounds such as the silver halides, used for photographic applications, are not stable under light illumination. The silver orthophosphate we use is no exception," says Yi, who first discovered the new property while working in Japan.

Although the instability of this silver orthophosphate compound is what makes the water splitting possible, it was also a potential drawback as stability is important for long time usage.

But the ANU scientists and their colleagues have overcome this problem by developing a technique for regenerating the silver orthophosphate in an energy-efficient way.

"On the laboratory scale it seems to work well. We think this is a very important and encouraging first step," say Withers. "But of course if you are going to use it on a large scale there are many questions to answer."
Decontaminant

Meanwhile, the researchers also found that silver orthophosphate can be used as a means of cleaning chemical contaminants out of water, again only using sunlight.

"Under visible light illumination, this material shows an amazing ability to oxidize water to release oxygen as well as to decompose organic contaminants such as methylene blue and Rhodamine B," says Yi.

"We believe it has got good potential for industrial applications," adds Withers. The research team says they are hoping to work with industrial partners to develop these applications in the near future.

Print
Climate change impact on malaria questioned
Single lens glasses can help prevent falls
Movies manipulate our primal response
Luminescent sharks become invisible
Synthetic biology research gets a hearing
Source of ancient carbon 'burp' detected
Why the goddess of love is in a spin
Computer program recognises online sarcasm
New dinosaur had record-sized horns
Physicists solve missing neutrino mystery
Milk from grass-fed cows may be better
Crabs caught spying on rivals' love claws
Lifestyle may not boost breast cancer gene risk
'Trade-off' gene for plants discovered
Pacific islands growing, not sinking
Caffeine addicts get no real perk
Velvet worm's deadly slime revealed
SpaceX cleared for Florida lift-off
Cyborg rights 'need debating now'
Sunlight shines on silver technology
Mountain biking as risky as football, diving
Dusty simulations may reveal planets
Legal fight over breast cancer gene
Unions call for urgent nano information
Solar panel attraction deadly for insects
Meat eaters munched many ways: study
Snakes may be in decline worldwide
Dogs dumbed down by domestication
Menu
Fossil sheds new light on 'dino-bird'
DNA 'spiderbot' is on the prowl
GM cotton use increases fruit pest problem
Warming to kill off a fifth of all lizards
Super massive black hole given the boot
Ball lightning could be 'all in the mind'
Immune system could be used to test for TB
Mobile phone cancer link unclear, study
Teen brain wired to take risks
Synchrotron probes Egyptian beads
Argonauts 'gulp' air to swim freely
Space station gets a new room
'Digital genome' to protect dying data formats
Sweep yields leads for new malaria drugs
Researchers snap signs of illegal fishing
Spectrum reveals supernova surprise
Scientists create synthetic life
Eavesdropping a waste of energy
Star caught eating its offspring
Megafauna die-off may have cooled planet
Hepatitis C no longer 'death sentence'
Atoms bring quantum computing closer
Visualisation staves off constant craving
Experts debate homeopathy funding