Researchers at Penn State have developed a plant-based material that can selectively recover dysprosium, a critical rare earth element used in semiconductors, electric motors, and generators, El.kz reports citing Interesting Engineering.
The team engineered a modified form of cellulose that can separate dysprosium from other similar rare earth metals in a cleaner and potentially more scalable way.
Rare earth elements are essential to modern electronics, magnets, and energy systems. But separating them from one another is difficult and often environmentally damaging.
Current commercial processes rely heavily on chemical solvents and energy-intensive systems. According to the researchers, their cellulose-based approach could offer a simpler and greener alternative.
The work focuses on dysprosium, a heavy rare-earth element used to improve heat resistance in magnets and stabilize nuclear control rods. Demand is rising sharply.
“As technology advances, manufacturers will need more and more dysprosium — some forecasts estimate the demand for this material may surge over 2,500% in the next 25 years,” said Amir Sheikhi, associate professor of chemical engineering.
The team previously used cellulose-based compounds to recover neodymium from electronic waste.
This time, they targeted dysprosium specifically, aiming to separate heavy rare earth elements from lighter ones more efficiently.
Plant fibers target metals
To do this, the researchers modified cellulose at the molecular level. They created a nanoscale crystalline material about 100 nanometers long, known as anionic hairy cellulose nanocrystals.
These particles are covered with tiny chain-like structures that interact with metal ions in solution.
When added to a water-based mixture containing both neodymium and dysprosium, the material selectively captured dysprosium through adsorption.
The researchers observed that the modified cellulose chains reacted differently in the presence of dysprosium, effectively isolating it from the mix.
“Separating rare earth elements from one another has been extremely difficult, due to the metals’ very similar chemical structures,” Sheikhi said.
“We have been looking for a reliable way to separate heavy elements like dysprosium from lighter elements like neodymium, while avoiding the negative environmental side effects that come from current separation approaches.”
The team said the result was unexpected. Rather than the type of chemical groups alone driving selectivity, the structure and positioning of those groups on the nanocellulose played a major role.
“This is, to my knowledge, the first example of a cellulose-based adsorbent that can selectively filter between heavy and light rare earth elements,” Sheikhi said.
Cleaner rare earth recovery
Traditional rare earth separation facilities often require large industrial setups with extensive chemical processing. The researchers argue their approach reduces chemical use and could lower environmental impact if scaled.
The team plans to further refine the material and test its ability to isolate additional rare earth elements. Future work will focus on scaling the process for potential industrial use and improving recovery efficiency.
If successful, the method could support recycling efforts and reduce dependence on imported rare earth materials, especially as demand for electric vehicles and renewable energy technologies grows.