in study Published by the American Chemical Society Researchers have developed electrodes used for electrochemical extraction to efficiently extract uranium from seawater. These electrodes are free-standing, binder-free, metal-free, porous and aromatic.
Uranium is currently extracted from rocks, but Estimates The Nuclear Energy Agency indicates that 4.5 billion tons of uranium are floating in the oceans in the form of dissolved uranyl ions, and this reserve is a thousand times greater than what exists on Earth, which provides a new opportunity to provide a sustainable supply of nuclear fuel, especially since the reserves of uranium resources are limited on Earth. It represents a serious obstacle to the development of a sustainable nuclear energy industry.
What is nuclear energy?
Nuclear energy is a clean, low-carbon energy source and alternative to… Fossil fuels It provides an important guarantee for green development. Uranium is the main fuel for nuclear power reactors.
Nuclear power reactors release energy naturally stored within the atom and convert it into heat and electricity by splitting the atom apart, a process known as fission. Uranium has become the preferred element in this process as all its forms are unstable and radioactive, making it easy to fission.
Extracting uranium from seawater
And it counts practical Extracting uranium from the sea is a difficult process. Seawater has high ionic strength and complex interfering ions that hinder the extraction of uranium.
In addition, seawater contains abundant deposits of marine microorganisms and other biological organisms, which limits the practical application of uranium extractives in seas and oceans.
Also, the materials used to extract uranium do not have enough surface area to effectively trap ions, so the electrodes developed by the researchers in this study contain many microscopic nooks and crannies that can be used in the electrochemical capture of uranium ions from seawater.
To create these electrodes, the researchers used a flexible fabric woven from carbon fibres, and coated this fabric with two specialized monomers that were then polymerized. They then treated the fabric with hydroxylamine hydrochloride to add the amidoxime groups to the polymers. The natural porous structure of the fabric creates many small pockets so that the oxygen medium stabilizes and easily traps the uranyl ions.
During the experiments, the researchers placed the coated fabric as a cathode in seawater filled with uranium, added a graphite anode and ran a periodic current between the electrodes. Over time, a light yellow uranium-rich precipitate accumulated on the cathode cloth.
In this study, a high uranium extraction capacity was achieved within 24 days of operation, amounting to 12.6 milligrams of uranium per gram of coated active material used for extraction. The capacity of the coated material was higher than most other uranium extraction materials the team tested. The designed electrodes can effectively realize electrochemical uranium extraction through adsorption and electrocatalysis processes.
This method showed that the electrochemical method is three times faster than the physical and chemical adsorption method, and it also showed good selectivity against competing ions.
This study has given an in-depth mechanistic understanding and an effective strategy for electrochemical uranium extraction by electrodes from seawater.
