Currently, uranium is extracted from rocks, but uranium ore deposits are finite. According to reports, 4.5 billion tons of uranium are floating around in our oceans as dissolved uranyl ions. This reserve is over 1,000 times more than what’s on land.

A team of scientists has innovated a pioneering electrode material with enhanced surface area, successfully extracting uranium from seawater more effectively than previous methods. This advancement holds promise for a sustainable nuclear fuel source, utilizing the vast uranium reserves dissolved in the world’s oceans.

The vast oceans, which encompass a majority of the Earth’s surface and sustain countless species, also contain sparse amounts of uranium ions. These ions, if successfully extracted, have the potential to be a renewable source for nuclear power generation.

A recent study in ACS Central Science introduces an innovative material designed for electrochemical extraction, significantly enhancing the efficiency of retrieving these elusive uranium ions from seawater compared to previous methods.

In nuclear power plants, energy is generated by fission, a process where the nucleus of an atom is split, releasing stored energy as heat and electricity. Uranium is the preferred choice for this process due to its inherent instability and radioactive nature, which facilitates its splitting.

Traditionally, uranium is mined from terrestrial sources, which are limited in supply. However, the Nuclear Energy Agency suggests that the ocean holds about 4.5 billion tons of uranium in the form of uranyl ions, exceeding land-based reserves by over a thousand times.

Historically, the challenge in extracting uranium from seawater has been the lack of materials with adequate surface areas for effective ion trapping.

Addressing this, Rui Zhao, Guangshan Zhu, and their team have developed a new electrode material rich in microscopic indentations, enhancing the electrochemical collection of uranium ions from seawater.

The process began with a flexible carbon fiber cloth, onto which two specific monomers were applied and subsequently polymerized. The cloth was then treated with hydroxylamine hydrochloride to integrate amidoxime groups into the polymers.

Thanks to the cloth’s porous nature, it formed numerous small pockets, ideal for capturing uranyl ions. During testing, this coated cloth, serving as the cathode, was submerged in either natural or uranium-enriched seawater alongside a graphite anode.

A cyclic current was applied between the electrodes, leading to the accumulation of yellow uranium-based precipitates on the cathode cloth.

Experiments conducted with seawater from the Bohai Sea demonstrated that the electrodes could extract 12.6 milligrams of uranium per gram of water over 24 days, outperforming many other tested uranium extraction materials.

The electrochemical approach also proved to be about three times quicker than passive accumulation methods. This study presents a promising technique for harvesting uranium from seawater, potentially positioning the oceans as a new source of nuclear fuel.

The research received support from various institutions, including the National Key R&D Program of China, the National Natural Science Foundation of China, the Education Department of Jilin Province, the Department of Science and Technology of Jilin Province, the Central Universities’ Fundamental Research Funds, and the “111” project.

Source: 10.1021/acscentsci.3c01291

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