Search for ‘holy grail’ of solar fuels just took an exciting twist

30 Apr 2018

Image: Smallcreative/Shutterstock

In continuing efforts to produce a feasible, environmentally friendly solar fuel, researchers believe they may have found the answer.

While most are in agreement that our production and use of fossil fuels is simply no longer viable, there are many advocating for different alternatives, ranging from just switching to electric power or using plant-based biofuel.

One of these options – and believed to be the ‘holy grail’ of affordable, viable and environmentally friendly fuel – is solar fuel, a process that splits water into hydrogen and oxygen, and then uses the former to create hydrogen fuel.

The only problem is that existing solar-generated hydrogen methods are both costly and not very efficient, but a new breakthrough could be about to change all that.

In a paper published to Scientific Reports, a team from the University of Exeter revealed a revolutionary photoelectrode – an electrode that absorbs light before the beginning of the hydrogen extraction process – made from nanoparticles of the elements lanthanum, iron and oxygen.

The researchers believe this new type of photoelectrode is not only cheap to produce, but can also be recreated on a larger scale for mass and worldwide use.

“With growing economies and population, fossil fuels will not be able to sustain the global energy demand in a ‘clean’ manner as they are being exhausted at an alarming rate,” said lead author of the paper, Govinder Pawar.

“Alternative renewable fuel sources must be found which can sustain the global energy demand. Hydrogen is a promising alternative fuel source capable of replacing fossil fuels as it has a higher energy density than fossil fuels (more than double), zero carbon emissions and the only by-product is water.”

Can still be improved

This recent breakthrough helps overcome the biggest problem of solar energy, that being an inability to produce a semiconducting material suitable for the process.

In this instance, the lanthanum iron oxide used to create the material gave the ideal results for the production of hydrogen from water using sunlight, making it the strongest candidate yet for renewable hydrogen generation.

“Our material has excellent stability where after 21 hours of testing it does not degrade – ideal for water-splitting purpose,” Pawar said. “We are currently working on further improving our material to make it more efficient to produce more hydrogen.”

Colm Gorey was a senior journalist with Silicon Republic