Using the power of the sun to split water and produce hydrogen fuel is one of the most promising clean energy technologies being pursued. One of the biggest hurdles holding it back has been uncovering an efficient and stable semiconductor material for use in the water-splitting process, but that's just what a team from the University of Exeter now claims to have created.

Not only does using an artificial photosynthesis process to split water into its constituent hydrogen and oxygen atoms promise to be clean and produce zero carbon emissions, but the resulting hydrogen has more than double the energy density of fossil fuels and, when used, the only by-product is water. It would also provide an essentially limitless source of energy.

In the quest to reach this goal, the University of Exeter team has built a new photo-electrode, which absorbs light and triggers electrochemical transformations that extract hydrogen from water, using nanoparticles of lanthanum, iron and oxygen. Its creators claim the lanthanum iron oxide semiconducting material, which is produced using a cheap spray pyrolysis technique followed by a post annealing step, is "the strongest candidate yet for renewable hydrogen generation" as it is stable, low-cost, and should be scalable for mass use worldwide.

"We have shown that our LaFeO 3 photo-electrode has ideal band alignments needed to split water into its constituents (H 2 and O 2 ) spontaneously, without the need of an external bias," says Govinder Pawar, the lead author of the paper. "Moreover, our material has excellent stability where after 21 hours of testing it does not degrade, ideal for water splitting purpose. We are currently working on further improving our material to make it more efficient to produce more hydrogen."

The team's research appears in the journal Scientific Reports.

Source: University of Exeter