Highly-Efficient g-C3N4-based Photocatalysts for Radioactive Nuclide Uranium Reduction and Extraction from Water

Die Hu; Sai Zhang; Kun Xu; Chengchu Zeng

doi:10.6919/ICJE.202505_11(5).0016

Authors

Die Hu
Sai Zhang
Kun Xu
Chengchu Zeng

DOI:

https://doi.org/10.6919/ICJE.202505_11(5).0016

Keywords:

Photocatalysis; Reduction; Uranium; g-C3N4; Mechanism.

Abstract

With the continuous growth of global energy demands, the excess utilization of traditional energy sources inevitably causes a series of worldwide problems, incuding resource depletion, environment pollution and climate warming. The separation, enrichment, and extraction of uranium from wastewater and seawater have played an increasingly critical role in development of new green energy and industrial upgrading. Nowadays, the great challenge, which urgently needs to be addressed, is to explore new technology for efficient extraction of radioactive nuclide uranium from water bodies. In recent years, photocatalysis technology for uranium extraction has rapidly developed by reason of its capability for reducing soluble high-valance state uranium (U(VI)) to insoluable low-valance state U(IV), consequently achieving extraction of uranium as well as radioactive wastewater treatment. However, the existed photocatalytic materials still suffer from limitations, such as low reduction rates for U(VI), inhibition effects at ambient environment, lack of research on catalytic mechanism, and practical application barriers. Graphitic carbon nitride (g-C₃N₄), as an emerging two-dimensional layered polymeric semiconductor material, has been regarded as one of the most promising candidates for photocatalytic uranium extraction, owing to its simple synthesis, low cost, strong visible-light absorption, and adjustable electronic band structure. This review systematically introduces the recent advances of g-C₃N₄-based materials in photoreduction, fixation, and extraction of U(VI) from aqueous environments. Also, the processes and reaction mechanisms for typical photocatalytic extraction of U(VI) are presented in detail. Furthermore, the design strategies, U(VI) extraction performance, and advantages/limitations of g-C₃N₄-based photocatalysts are critically evaluated. At length, the future prospects of photocatalytic technology for U(VI) recovery from wastewater and seawater are discussed, highlighting its potential for sustainable energy solutions. This review aims to provide theoretical guidances for the rational design and development of novel photocatalytic materials to purify U(VI)-bearing wastewater and extract radionuclide resources.

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