Brilliant Iron Molecule Can Make Solar Energy Cheaper

Together with colleagues, Kenneth Wärnmark has for a long time worked to find alternatives to the expensive metals. The researchers focused on iron which, with its six per cent prevalence in the Earth’s crust, is significantly easier to source. The researchers have produced their own iron-based molecules whose potential for use in solar energy applications has been proven in previous studies.

In this new study, the researchers have moved one step further and developed a new iron-based molecule with the ability to capture and utilise the energy of solar light for a sufficiently long time for it to react with another molecule. The new iron molecule also has the ability to glow long enough to enable researchers to see iron-based light with the naked eye at room temperature for the first time.

“The good result depends on the fact that we have optimised the molecular structure around the iron atom”, explains colleague Petter Persson of Lund University.

The study is now published in the journal Science. According to the researchers, the iron molecule in question 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. Furthermore, the new findings open up other potential areas of application for iron molecules, e.g. as materials in light diodes (LEDs).

What surprised the Lund researchers is that they arrived at good results so quickly. In just over five years, they succeeded in making iron interesting for photochemical applications, with properties largely as good as those of the best noble metals.

“We believed it would take at least ten years”, says Kenneth Wärnmark.

Besides the researchers from Lund University, colleagues from Uppsala University and the University of Copenhagen were also involved in the collaboration.

Contacts and sources:
Lund University

Citation:Luminescence and reactivity of a charge-transfer excited iron complex with nanosecond lifetime 
Kasper Skov Kjær1,*, Nidhi Kaul2,*, Om Prakash3,*, Pavel Chábera1, Nils W. Rosemann1, Alireza Honarfar1, Olga Gordivska3, Lisa A. Fredin4,†, Karl-Erik Bergquist3, Lennart Häggström5, Tore Ericsson5, Linnea Lindh1, Arkady Yartsev1, Stenbjörn Styring2, Ping Huang2, Jens Uhlig1, Jesper Bendix6, Daniel Strand3, Villy Sundström1,‡, Petter Persson4,‡, Reiner Lomoth2,‡, Kenneth Wärnmark3,‡ Science 29 Nov 2018: eaau7160