Graphitic carbon nitride-based materials for photocatalytic reduction of U(VI)

The technology of photocatalytic reduction of U(VI) has wide application prospects in uranium recovery from seawater and in disposal of uranium waste because of its high efficiency, low cost, pollution-free nature and high selectivity. Graphitic carbon nitride (g-C₃N₄)-based materials have been regarded as ideal photocatalysts for the photocatalytic reduction of U(VI) (PCRU) because of their appropriate bandgap, unique two-dimensional (2D) layered structures, excellent physicochemical stability and outstanding optical properties; however, only few systematically reported on the visible light-driven catalytic reduction of U(VI), especially the process and mechanism of PCRU using graphitic carbon nitride-based materials. In this review, we systematically discuss the possible mechanism of PCRU. The PCRU using g-C₃N₄-based materials is reviewed in detail. On this basis, the g-C₃N₄-based materials widely employed in PCRU are reviewed. Then, the factors affecting PCRU with g-C₃N₄-based materials are addressed. Lastly, the current difficulties and future prospects of g-C₃N₄-based materials on PCRU are provided.