Overlooked 'in-between' materials could reshape solar fuel and battery design - Energy & Green Tech - Hi Tech & Innovation

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Researchers have identified previously unknown materials, including a new form of a widely studied clean-energy material, by carefully controlling and tracking how molecular precursors break down during heating.

Published in Nature Communications, the study uncovers a series of hidden intermediate stages that appear when molecules are heated to become materials. Capturing these intermediates opens a new way to discover and design materials that aren't accessible through typical synthetic methods.

Dr. Sebastian Pike, Department of Chemistry, University of Warwick, said, "When materials are made by heating, scientists usually focus on the final product, the 'B' that results from 'A.' But this study shows that there are many fascinating stages in between 'A' and 'B,' and these hidden steps could be just as important.

"We didn't know exactly what we would find going in, but we were confident there would be something interesting and unknown in the intermediate phases. We were thrilled to discover that some of these could have practical uses, even from the very first experiments."

Starting with specially designed "single-source precursors," molecules containing all the elements needed to create a material, the team tracked how they transformed during heating. This revealed several new material phases, including a previously unknown, kinetically stabilized form of bismuth vanadate (BiVO₄) named β-BiVO₄.

BiVO₄ is a valuable clean energy material because it has a "band gap" (the energy it needs to absorb sunlight and drive chemical reactions) that hits a sweet spot: it absorbs sunlight efficiently while still providing enough energy to split water and produce clean hydrogen fuel.

The newly discovered β-BiVO₄ has a different atomic structure from previously known forms of the material. The new variant has a significantly larger band gap, meaning it interacts with light differently. This could offer new opportunities for tuning the performance of materials used in solar fuel generation, catalysis, and electronics.

The potential applications were not limited to solar fuels. Another of these hidden intermediate materials was found to store large amounts of lithium, suggesting it could be useful for next-generation battery technologies.

Dr. Dominik Kubicki, school of Chemistry, University of Birmingham, said, "What's exciting is that these 'in-between' materials aren't just stepping stones—they can have useful properties in their own right. By understanding and controlling how they form, we can start to design better materials for batteries, catalysis, and solar energy."

The researchers were able to observe these normally hidden intermediate states by combining state-of-the-art techniques—including solid-state NMR spectroscopy, X-ray diffraction, and pair distribution function analysis.

They also found that the choice of precursor, and how it breaks down, can be used as a powerful tool to control material formation, allowing the team to access structures that are difficult to produce using conventional heating methods.

Dr. Pike concluded, "We only studied a few precursors here, but this work points to a broader opportunity in materials science. By carefully controlling temperature, precursor chemistry, and reaction pathways, there may be many more 'hidden' but extremely useful materials to be found." 

Provided by University of Warwick 

by University of Warwick

edited by Sadie Harley, reviewed by Robert Egan 

Source: Overlooked 'in-between' materials could reshape solar fuel and battery design