Direct Production of Hydrogen from Sunlight

Outside the Box

Posted by Randy Graves on May 1, 2018

The long sought R&D goal to develop affordable, viable and environmentally-friendly fuels using sunlight has taken a great leap forward with pioneering efforts by a team of renewable energy researchers from the University of Exeter, who have developed a new technique to produce hydrogen directly from sunlight using an innovative metal catalyst: LaFeO3.

The printed bridge is scheduled to be placed over a historic canal in Amsterdam and opened to the public in 2019.

The University of Exeter team developed an innovative new photo-electrode, which absorbs light and then triggers electrochemical transformations using nanoparticles of lanthanum, iron and oxygen. Govinder Pawar, research team member and lead author on the University of Exeter research paper, based at the University of Exeter's Environment and Sustainability Institute, claims the lanthanum iron oxide semiconducting material, 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 LaFeO3 photo-electrode has ideal band alignments needed to split water into its constituents (H2 and O2) spontaneously, without the need of an external bias.”

See the technical report here.

The potential for commercial generation of hydrogen is significant owing to the potential low cost of the LaFeO3 but problems do exist, principally the separation of the hydrogen from the oxygen generated. That is if a single catalyst creates both H₂ and O₂ in the same reaction zone, they’ll mix producing a potentially explosive mixture. It may be possible to separate the components in situ with a simple arrangement of porous membranes: hydrogen readily permeates and diffuses thru membranes, and oxygen not so much.

This innovative LaFeO3 photo-electrolysis development looks extremely promising and could fuel a revolutionary paradigm change in the way hydrogen is generated from water. This photo-electrolysis produced hydrogen can be used as a fuel that would not only severely reduce world-wide carbon emissions, but would also create a virtually limitless environmentally friendly energy source.

What do you think?