Method uses sun’s energy to create clean hydrogen source

Australian researchers are developing a method to create a truly clean and portable source of hydrogen for cars and fuel cells using energy from the sun.

The technology will rely on nanoparticles that, under certain conditions, can use solar energy to catalyse the conversion of water to hydrogen — in a process known as photo-initiated catalysis.

While the technology for utilising hydrogen in cars and fuel cells is quite mature, a means of obtaining hydrogen cleanly and cheaply is still a major sticking point in terms of widespread adoption of a hydrogen economy.

‘Splitting water to make hydrogen and oxygen requires a lot of energy and is an expensive process,’ said project lead Prof Greg Metha of Adelaide University.

‘We will be using solar radiation as the energy source, so there will be no carbon emissions; because the clusters work so efficiently as a catalyst, it will be a much better process.’

A research group headed by Metha has been working for 14 years developing bi-metallic and metal-carbide clusters using a technique known as double-laser ablation. The result is tailored nanoparticles less than 10 atoms in size that act as ‘super-efficient catalysts’, according to the group.

Speaking to The Engineer, Metha said the group now had to demonstrate that these principles worked on the macroscopic scale.

’Initially we will be using light from a laser or a solar lamp, which will allow us to test efficiency as a function of light intensity and also temperature — this will determine how much focusing is optimal.’

He added: ’Work on high-intensity solar simulators is being done by my engineering colleagues so we will integrate our ideas when the time is right; however, at present we just don’t know what the best conditions are.’

The project ’Solar Hydrogen: photocatalytic generation of hydrogen from water’, has been funded under the three-year clean energy partnership between Adelaide Airport and the university’s Centre for Energy Technology.