As countries expand nuclear power to support low-carbon energy goals, securing a stable supply of uranium has become an increasingly important scientific and environmental challenge. A new review published in Biochar examines how biochar-based porous materials could provide a more sustainable route for selectively separating uranium from complex water systems, including seawater, salt lakes, groundwater, and nuclear wastewater.
Uranium is a key fuel for nuclear power, but it often exists at very low concentrations in natural waters and is mixed with many other metal ions. This makes efficient and selective recovery difficult. The review, led by Zhenli Sun, Zhongshan Chen, Yuan Chen, Xishi Tai, Suhua Wang, Jiehong Lei, Qizhao Wang, Fuyou Fan, Bin Ma, and Xiangke Wang, summarizes recent progress in using biochar and biochar-based porous materials to capture uranium through sorption, precipitation, photocatalysis, and electrocatalysis.
"Biochar gives us a versatile platform for uranium separation because it can be produced from biomass, modified with targeted functional groups, and combined with catalytic strategies," said corresponding author Prof. Xiangke Wang. "The key is not only removing uranium, but doing so selectively in real water systems where many competing ions are present."
Biochar is a carbon-rich material commonly produced from agricultural residues, plant biomass, or other organic wastes. Its porous structure, relatively low cost, large-scale production potential, and environmental compatibility make it attractive for water treatment. However, raw biochar often lacks the strong selectivity needed to target uranium in complex solutions. The review shows that this limitation can be addressed by engineering the material surface.
According to the authors, functional groups such as amidoxime, phosphate, amino, hydroxyl, and carboxyl groups can help biochar bind uranium more strongly. In sorption-based systems, uranium ions may attach to biochar through electrostatic attraction, ion exchange, and chemical complexation. In precipitation-based systems, uranium can be transformed into solid uranium-containing compounds. Photocatalytic and electrocatalytic approaches can further drive uranium reduction or precipitation under light or electrical input, enabling continuous extraction under low-concentration conditions.
The review also emphasizes that no single strategy fits every water system. Sorption is simple and suitable for large-scale use, precipitation can be effective at higher uranium concentrations, while photocatalysis and electrocatalysis offer promising routes for continuous recovery from dilute systems. Selecting the right approach depends on water chemistry, uranium concentration, competing ions, and the properties of the biochar-based material.
Another important theme is the growing role of machine learning. The authors suggest that data-driven models could help researchers connect biochar feedstocks, modification methods, surface chemistry, pore structure, and uranium separation performance. Such tools may accelerate the rational design of next-generation materials and reduce trial-and-error experimentation.
Despite strong progress, the review notes that practical deployment still faces challenges. These include improving selectivity in real waters, ensuring long-term stability and reusability, understanding molecular-level mechanisms, standardizing performance evaluation, and validating materials in pilot-scale systems.
"Future work should move beyond laboratory removal efficiency and focus on real environmental conditions, regeneration, cost, and safety," said Prof. Wang. "With better material design and data-guided optimization, biochar-based porous materials could become an important part of sustainable uranium recovery and nuclear wastewater management."
By bringing together material synthesis, separation mechanisms, catalytic strategies, and machine learning perspectives, this review provides a roadmap for turning biomass-derived carbon materials into advanced tools for uranium resource recovery and environmental protection.
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Journal Reference: Sun, Z., Chen, Z., Chen, Y. et al. Highly selective separation of uranium by biochar-based porous materials through sorption, precipitation, photocatalysis, and electrocatalysis strategies. Biochar 8, 119 (2026).
https://doi.org/10.1007/s42773-026-00621-z
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About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
