Researchers observed the process of nanoparticles in-depth.
A research team used X-ray beams of the European Synchrotron ESRF and noticed that "electrons released by cerium dioxide nanoparticles during chemical reactions" did not bind to single atoms as was originally believed, a European Synchrotron Radiation Facility news release reported. Instead of binding to atoms, the electrons move "like a cloud" and distribute themselves across the entire nanoparticle.
The researchers dubbed the phenomenon (based on its shape) the "electron sponge."
Cerium dioxide nanoparticles are commonly used in certain consumer products. They are generally found in the walls of self-cleaning ovens, they work as a "high-pressure catalyst to aid in the cleaning process. In the future, they may be used in lithium-ion batteries, giving them better storage and more power.
Researchers are working to gain more insight into the behavior of Cerium (which is mined from the Earth's crust) in hopes of widening the range of its applications in the future. The research is also crucial in making sure Cerium is used safely.
"Most chemical reactions involve the transfer of an electron from one atom to another. In the past, it was believed that the electrons involved in a chemical reaction on the surface of a nanoparticle were localised in one of the atoms at the surface," the news release reported.
The researchers used the X-ray beams to look into nanoparticle solutions in water and ethanol. Researchers have observed that nanoparticles change their behavior under a vacuum, so the team made sure to study them in a realistic environment.
"It was only possible to conduct these experiments in a liquid rather than under vacuum because we used X-rays as probes for the electron distribution," Jean Daniel Cafun, a leader of the study, said.
Using this method the team was able to observe the nanoparticles' creating and the elimination of highly reactive molecules. The phenomenon mimics a process in the body that "protects cells from aggressive molecules."
Cancer patients undergoing treatment have a high level of these reactive molecules in their bodies, researchers believe ceria nanoparticles could help reduce these levels.
"Scientists have been discussing the question: What happens when electrons are added to ceria nanoparticles? The work by Cafun et al. is a key study because it questions the present, widely accepted model and will lead the research in a new direction." Frank de Groot, an expert on nanomaterials at Utrecht University who did not take part in the experiment, said.
