Researchers at the Swiss Federal Institute of Technology in Lausanne, led by Michael Gratzel, have developed methods for generating fuels such as hydrogen through solar water splitting.
To do this, they either use photoelectrochemical cells that directly split water into hydrogen and oxygen when exposed to sunlight, or they combine electricity-generating cells with an electrolyzer that separates the water molecules.
By using the latter technique, Gratzel's post-doctoral student Jingshan Luo and his colleagues were able to obtain a spectacular performance.
Their device converts into hydrogen 12.3 per cent of the energy diffused by the Sun on perovskite absorbers - a compound that can be obtained in the laboratory from common materials, such as those used in conventional car batteries, eliminating the need for rare-earth metals in the production of usable hydrogen fuel.
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"Both the perovskite used in the cells and the nickel and iron catalysts making up the electrodes require resources that are abundant on Earth and that are also cheap," said Luo.
"However, our electrodes work just as well as the expensive platinum-based models customarily used," Luo added.
On the other hand, the conversion of solar energy into hydrogen makes its storage possible, which addresses one of the biggest disadvantages faced by renewable electricity - the requirement to use it at the time it is produced.
Such a gas can be burned - in a boiler or engine - releasing only water vapour. It can also pass into a fuel cell to generate electricity on demand, researchers said.
They hope the 12.3 per cent conversion efficiency they achieved will soon get even higher.
The study is published in the journal Science.