Fabrication of novel heterojunction of (1D) Nb2O5 nanorod/(0D) CdS nanoparticles for efficient removal of U(VI) from water

As an effective treatment method for uranium removal in wastewater, the application of photocatalytic reduction has attracted extensive attention. To improve the optical performance of Nb 2 O 5 , CdS nanoparticles were introduced via a one-step hydrothermal method. Then the characterization by various methods (e.g. XRD, SEM, TEM, XPS and UV–vis DRS) were used to determine the structural and optical properties of the heterojunction of Nb 2 O 5 nanorod/CdS nanoparticles (NC). It clearly confirmed that the successful construction of the heterojunction widened the visible light absorption range, narrowed bandgap (∼2.11 eV), promoted the charge transfer and enhanced the separation efficiency of photoinduced electron-hole pairs and further improved the photoreduction activity. During the photocatalytic degradation process, the results showed the photocatalyst with the Nb/Cd molar ratio of 1/3 (NC-3) displayed the best removal of U(VI), with a removal efficiency of 97% in 90 min adsorption and 150 min visible light irradiation at the pH=6. The NC-3 photocatalyst was relatively stable and exhibited good recyclability in during the cyclic experiments. In the end, it was proposed that e - and O 2 - radicals played important roles in the process of the reduction of U(VI).