Morphology Effect of FeWO4 Boosting Efficiency of Photocatalytic Uranium Extraction under Visible Light and Mechanism Investigation

Wolframite (FeWO4) is a type of polyoxometalate known for its high chemical stability and electronic properties, which makes it an excellent photocatalyst. While FeWO4 has been widely utilized in the domain of organic catalysis, there are currently no documented reports regarding its use in the degradation of U(VI). In this study, the effect of changing the microscopic morphology of the FeWO4 catalyst to enhance its photocatalytic activity was explored. We effectively adjusted the microstructure and crystallinity of the FeWO4 catalyst by varying the hydrothermal synthesis temperature, subsequently analyzed in detail using synchrotron radiation and theoretical calculations. Additionally, the degradation rate of U(VI) in nuclear wastewater reached 98.8% using the FeWO4 catalyst samples synthesized at 200 °C, and the effect of coexisting ions on the performance of FeWO4 was studied, and the results showed that the degradation effect of certain amounts of Na+, Mg2+, K+, and Ca2+ on U(VI) was almost negligible, and it still maintained more than 90% of its initial performance after six cycles, which highlights the wide application prospects of the catalyst in the field of nuclear wastewater treatment in the future. Therefore, FeWO4 exhibits excellent photocatalytic uranium-extraction ability, anti-interference ability, stability, and a low-cost advantage. It holds great application prospects in the field of extracting radioactive uranium from nuclear wastewater.