Scientists at the Qinghai Institute of Salt Lakes in China have invented a microscopic, light-powered material that can swim through water and actively capture uranium ions, much like a predator hunting its prey. This micromotor has been crafted from a metal-organic framework and is just a few micrometres in size, much thinner than a human hair.
The advent of such an invention could help industries harness uranium from seawater, which contains close to 4.5 billion tons of uranium but in extremely low concentrations. Until now, its extraction has been too complex and expensive; hence, the Chinese micromotor could be a breakthrough.
Uranium is used as fuel in nuclear fission reactors. As China embarks on a mission to move away from fossil fuels and, in the future, explore nuclear fission energy, it requires a steady supply of uranium to power its reactors.
Last year, the largest uranium mining project in the country began operations, and the Asian giant also relies on imports to fuel its reactors. China is currently exploiting its salt lakes to source potassium and lithium. A research team led by Yongquan Xhou at the Institute of Salt Lakes found a way to extract uranium from these lakes using micromotors.
Uranium Abundance in the Sea
The metal-organic framework being used by the scientists is 30 times smaller than a human hair, measuring just 2 micrometres wide. Although its internal structure is like a sponge, researchers have slightly modified it to keep it stable in water for longer. The molecule is activated with hydrogen peroxide, and the micromotors move the particles at 7 micrometres per second. Sunlight can also be used as a boost, since it can enhance the propelling speed of the particle.
Testing in laboratory settings has revealed that the material can extract 406 milligrams of uranium per gram. Once the material encounters a uranium ion, it locks it into a stable mineral form, safely storing it.
All previous systems of extraction used passive power. Scientists have cautioned that the technology is still in its nascent stages and cannot be deployed at scale. China seeks to develop it further to extract uranium, along with potassium and lithium, from the sea.
