Scientists find hidden materials that could improve batteries and solar fuels

The research, published in Nature Communications, focuses on intermediate phases that appear while molecules are being converted into solid materials. These temporary stages are often overlooked because scientists typically concentrate on the final product. By capturing and studying them, the researchers found a possible route to materials that are difficult or impossible to obtain through conventional synthesis.

Hidden Stages During Material Formation

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."

The researchers began with specially designed 'single-source precursors', molecules containing all the elements needed to create a material. They then monitored how those molecules changed as temperatures increased.

This approach exposed several previously unknown material phases. One was a new, kinetically stabilized form of bismuth vanadate (BiVO₄), which the researchers named β-BiVO₄.

A New Form of Bismuth Vanadate

BiVO₄ has attracted attention in clean energy research because of its useful "band gap" (the energy it needs to absorb sunlight and drive chemical reactions). Its properties allow it to absorb sunlight effectively while still supplying enough energy to split water and generate clean hydrogen fuel.

The newly identified β-BiVO₄ has an atomic arrangement that differs from known forms of the material. It also has a significantly larger band gap, which changes the way it interacts with light.

Those differences could give researchers new ways to adjust materials for use in solar fuel production, catalysis, and electronics.

Potential for Next Generation Batteries

The newly discovered intermediate phases may also have uses beyond solar energy. Another hidden material identified during the experiments was able to store large amounts of lithium, raising the possibility that it could contribute to 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."

To observe these normally hidden states, the researchers combined several state-of-the-art techniques, including solid-state NMR spectroscopy, X-ray diffraction, and pair distribution function analysis.

Their results also showed that the precursor selected at the beginning of the process, along with the way that precursor decomposes, can strongly influence which materials form. By controlling those factors, researchers may be able to produce structures that are difficult to obtain using standard heating methods.

A New Route to Undiscovered Materials

The findings suggest that temporary stages in material formation could represent a largely unexplored source of useful compounds. Instead of treating intermediate structures only as brief steps on the way to a final material, scientists may be able to deliberately create and stabilize them for practical applications.

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."