High-Entropy Inorganic Materials to Advance Sustainable Uses

Scientists in Manchester are spearheading investigations into the potential of inorganic high-entropy materials (HEMs). Due to the paradoxical stabilization of chaos in their structure, HEMs deviate from the conventional understanding of a material, which is that of something stabilized by forming bonds with other atoms.

Their disorder renders them a potentially revolutionary technology for the development of sustainable energy, encompassing thermoelectric power generation, energy-storage batteries, chemical catalysis, and electrocatalysis.

Engineering New Materials with Exciting Properties

Professor David J Lewis, Head of the Department of Materials, leads a team of material scientists developing high-entropy materials from the ground up. By incorporating a ‘cocktail’ of various metal atoms into the lattice, they are creating materials with previously unknown and fascinating features.

During their investigation, the researchers discovered that the materials had a variety of capabilities, including their capacity for electrocatalytic water splitting.

HEMs offer great potential as a disruptive technology in chemical catalysis since they have so many distinct sites within the material.

It is almost like combinatorial chemistry at the atomic scale. This can be illustrated with a simple calculation. If one starts to imagine the number of unique sites in a high entropy material which contains six or more different elements, including the three nearest neighbor atoms, you are looking at combinations in the order of 10³³.

David Lewis, Professor, Materials Chemistry, University of Manchester

Lewis added, “Compare that to the amount of known ‘vanilla materials’ as I would call them, well there is only about 10¹² of those – so you can really start to produce almost unimaginable combinations of active sites within a catalyst. We have also shown that this approach can activate different structural features in electrocatalysts that lie dormant in the parent materials, and with it, improvements in efficiency.”

The group led by Professor Lewis demonstrated for the first time how these materials can show quantum confinement at short length scales (10^–9 m), opening up the intriguing possibility of emergent characteristics arising from both intrinsic disorder and quantum processes.

Looking to the Future

Professor Lewis’ team creates high-entropy materials from the atom up, suggesting in a recent publication that this approach, in general, is the best technique for achieving entropic stabilization. This indicates that researchers could alter the composition of a material based on the molecular precursors initially added to the pot.

Despite the growing interest in high entropy materials, there are still significant obstacles in characterizing and computational simulation of the systems, which Professor Lewis’ research will address in the future.

Lewis added, “There are still a number of outstanding challenges, and the nature of these are very interdisciplinary. I have been lucky enough to be able to collaborate with many other academics all at the same institution that share my interest in these problems. To me, therefore, Manchester is the ideal place to conduct this research.”

Journal Reference:

Ward-O’Brien, B., et al. (2024) Quantum Confined High-Entropy Lanthanide Oxysulfide Colloidal Nanocrystals. Nano Letters. doi:10.1021/acs.nanolett.2c01596