Ni‐Single‐Atom Mediated 2D Heterostructures for Highly Efficient Uranyl Photoreduction

Abstract

Sunlight‐driven photoreduction of the environmentally mobile uranyl (VI) to less soluble tetravalent uranium is of considerable value to environmental sustainability, yet the pursuit for high‐performance semiconductors is plagued by the current disadvantages of inferior charge separation/migration. This study reports that a nickel single atom isolated on a sulfur‐functionalized graphitic carbon nitride/reduced graphene oxide 2D heterostructure enables exceptional uranyl photoreduction. Under only 11 min of visible light irradiation, the single atom anchored semiconductor yields a high removal rate of 99.8% and a record‐high extraction capacity of 4144 mg g−1 in uranyl‐containing wastewater and seawater. Theoretical calculations confirm that the remarkable uranyl photoreduction originates from the synergetic effect of Ni single atoms and intimate heterojunction establishment that can not only promote the separation/migration of photoexcited carriers, but also greatly reduce the energy barrier of uranyl reduction. This study showcases the exciting potential of single atom semiconductors for efficient uranyl removal from uranium‐contaminated aqueous environments.

Nickel single atom mediated phosphate functionalization of moss derived biochar effectively enhances electrochemical uranium extraction from seawater

“…The normalized X-ray absorption near edge structure (XANES) spectrum of Ni–BC@PO 4 is observed between the spectra of metallic nickel foil and nickel oxide, indicating the oxidation state of Ni in Ni–BC@PO 4 is between 0 and +2 (ref. 31) (Fig. 2e).…”

Extraction of Uranium by a Pyrazole-Based Porous Organic Polymer

“…In X-ray photoelectron spectroscopy (XPS), the tetravalent uranium was revealed, as evidenced by the peaks of U 4f 7/2 and U 4f 5/2 at 381. 392.6 eV (Figure 2b), 34 respectively. As shown in Figure S6, the FT-IR spectrum of the sample after the reaction showed a peak belonging to −U−O located at 915 cm −1 .…”

“…To confirm this claim, we first carried out a combined scanning electron microscopy (SEM)–energy-dispersive spectroscopy test, where the uranium element can be clearly read out on the surface of the samples (Figure S5). In X-ray photoelectron spectroscopy (XPS), the tetravalent uranium was revealed, as evidenced by the peaks of U 4f 7/2 and U 4f 5/2 at 381.6 and 392.6 eV (Figure b), respectively. As shown in Figure S6, the FT-IR spectrum of the sample after the reaction showed a peak belonging to −U–O located at 915 cm –1 .…”

Exploring Electron Transfer Mechanism in Synergistic Interactional Reduced Polyoxometalate-Based Cu(I)–Organic Framework for Photocatalytic Removal of U(VI)

“…9−11 Uranium exists as a form of dissolved UO 2 2+ in the uranium-containing wastewater, which possesses a strong migration capacity. 12 If it enters the natural environment through natural infiltration and water migration, it will cause serious harm to the ecosystem and human health. Therefore, reducing soluble U(VI) to insoluble U(IV) is regarded as a most up-and-coming strategy for the elimination of uranium pollutants.…”