Fabrication of g-C3N4-based conjugated copolymers for efficient photocatalytic reduction of U(VI)

The photocatalytic reduction of hexavalent uranium(U(VI)) is considered to be a preferred approach for uranium extraction from seawater and treatment of uranium-contained wastewater. In this paper, we constructed intramolecular electron-donors doped conjugated copolymers by integrating thiophene donors into graphitic carbon nitride (g-C3N4) skeleton to achieve efficient photocatalytic reduction of U(VI). Compared with pristine g-C3N4, thiophene doped samples exhibit excellent optical and electrical properties, resulting in the efficiency of U(VI) photocatalytic reduction, which is 1.83 times higher than that of g-C3N4. The effects of the doping amount of thiophene, initial uranium concentration, solution pH, on the U(VI) removal by thiophene doped samples were preliminarily investigated. To verify the performance of the catalyst under the actual application conditions, we tried to use sunlight instead of the light source of the experimental system. Besides, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to explore the reaction mechanisms.

Automated summary

The study improved the efficiency of photocatalytic reduction of hexavalent uranium using thiophene-doped conjugated polymers integrated into the graphitic carbon nitride skeleton. It was demonstrated that doping significantly enhances the photocatalytic reduction efficiency.