We always love a good clean energy breakthrough story. From improved storage to bacteria-powered cleantech, scientists are always busy investigating clean energy techniques and developments.
However, this latest breakthrough caught our eye in particular because it involves some Nobel-winning chemistry.
A mixture of metals
Back in 2017, Joachim Frank, Richard Henderson and Jacques Dubochet were awarded the Nobel in chemistry for pioneering a biological technique known as the 'single particle reconstruction'. This electron microscopy technique at the time was used to reveal only the structures of viruses and proteins.
Now, a team at the University of Manchester, in collaboration with researchers at the University of Oxford and Macquarie University, have adapted the technique, for the first time ever, to be used on a mixture of metals.
The result is atomic scale chemistry in metal nanoparticles creating materials that are ideal catalysts for energy converting systems. The particles produced have a star-shaped geometry where their edges can now have different chemistries. These chemistries can then be adapted to reduce the cost of batteries and catalytic converters.
3D imaging achieved
What the scientists effectively achieved is the possibility to map different elements, such as metal nanoparticles, at the nanometre scale in 3D without damaging them. Metal nanoparticles are the primary components in many catalysts. In fact, these catalysts' effectiveness is highly dependent on these nanoparticles' structures.
However, due to their minuscule structure, electron microscopes are required in order to properly image them. Up to now, most imaging was limited to 2D projections because the small particles would be damaged by 3D imaging.
"We have been investigating the use of tomography in the electron microscope to map elemental distributions in three dimensions for some time," said Professor Sarah Haigh, from the School of Materials, University of Manchester.
"We usually rotate the particle and take images from all directions, like a CT scan in a hospital, but these particles were damaging too quickly to enable a 3D image to be built up. Biologists use a different approach for 3D imaging and we decided to explore whether this could be used together with spectroscopic techniques to map the different elements inside the nanoparticles."
"Like 'single particle reconstruction' the technique works by imaging many particles and assuming that they are all identical in structure, but arranged at different orientations relative to the electron beam. The images are then fed into a computer algorithm which outputs a three-dimensional reconstruction."
The researchers have dedicated their first study to investigating platinum-nickel (Pt-Ni) metal nanoparticles and with good reason.
"Platinum-based nanoparticles are one of the most effective and widely used catalytic materials in applications such as fuel cells and batteries. Our new insights about the 3D local chemical distribution could help researchers to design better catalysts that are low-cost and high-efficiency," explained Lead author, Yi-Chi Wang, also from the School of Materials.
But their work is not yet finished and the researchers hope to not only automate their process but to also see it used in all kinds of alternative energy cases.
"We are aiming to automate our 3D chemical reconstruction workflow in the future", added author Dr. Thomas Slater.
"We hope it can provide a fast and reliable method of imaging nanoparticle populations which is urgently needed to speed up optimization of nanoparticle synthesis for wide-ranging applications including biomedical sensing, light emitting diodes, and solar cells."
The study was published in the journal Nano Letters.