Chemistry researchers at the University of Adelaide, Australia are exploring how metal nanoparticles act as highly efficient catalysts in using solar radiation to split water into hydrogen and oxygen.

"Efficient and direct production of hydrogen from solar radiation provides a renewable energy source that is the pinnacle of clean energy," said Associate Professor Greg Metha, Head of Chemistry. "We believe this work will contribute significantly to the global effort to convert solar energy into portable chemical energy."

The latest research is the outcome of 14 years of fundamental research by Metha's research group investigating the synthesis and properties of metal nanoparticles and how they work as catalysts at the molecular level. The group works with metal clusters of about one-quarter of a nanometer in size - less than 10 atoms. Metha said these tiny "magic clusters" act as super-efficient catalysts.

"We've discovered ways of producing these tiny metallic clusters, we've explored their fundamental chemical activity, and now we are applying their catalytic properties to reactions which have great potential benefit for industrial use and the environment," he said.

Ph.D. student Jason Alvino is exploring splitting water to make hydrogen (and oxygen) using solar energy - a process that is not viable for industry development at the moment.

"We know this catalysis works very efficiently at the molecular level and now need to demonstrate it works on the macroscopic scale," said Metha.

"Splitting water to make hydrogen and oxygen requires a lot of energy and is an expensive process. We will be using solar radiation as the energy source, so there will be no carbon emissions and because the clusters work so efficiently as a catalyst, it will be a much better process. The ultimate aim is to produce hydrogen from water as a cheap portable energy source."

Metha said there were also other industrial chemical reactions that could be made feasible by these catalysts, using solar radiation as the energy source - with potentially significant environmental benefits. One example was converting carbon dioxide into methane or methanol with water.

(University of Adelaide)