An iron molecule that can function both as a photocatalyst to produce fuel and in solar cells to produce electricity has been discovered. It could replace the more expensive and rare metals used today.
Some photocatalysts and solar cells are based on a technology that involves molecules containing metals, or metal complexes, that can absorb solar rays and use their energy.
However, the metals in these molecules are rare and expensive, such as the noble metals ruthenium, osmium and iridium.
Now, researchers have for the first time discovered an iron molecule that could replace these more expensive metals by functioning as a photocatalyst and in solar cells.
“Our results now show that by using advanced molecule design, it is possible to replace the rare metals with iron, which is common in the Earth’s crust and therefore cheap,” explained Professor Kenneth Wärnmark of Lund University in a statement.
The researchers focused on iron which, with its six per cent prevalence in the Earth’s crust, is relatively easy to source. They then produced their own iron-based molecules whose potential for use in solar energy applications has been proven in previous studies.
For the new study, they went further to develop a new iron-based molecule with the ability to capture and utilise the energy of solar light long enough for it to react with another molecule. It can also glow long enough to enable the researchers to see iron-based light with the naked eye at room temperature for the first time, according to the statement.
The iron molecule could be used in new types of photocatalysts for the production of solar fuel, either as hydrogen through water splitting or as methanol from carbon dioxide, say the researchers. The new findings also open up other potential areas of application for iron molecules, such as materials in light diodes (LEDs).
Photo credit: Jonathan Potts/ CC BY-NC-ND 2.0