Enhancing the photocatalytic performance of g-C3N4 by using iron single-atom doping for the reduction of U(VI) in aqueous solutions

Photocatalysis is regarded as a safe, efficient, and environmentally-friendly method for treating uranium containing waste water. In this work, novel Fe-doped graphitic carbon nitride (g-C3N4) photocatalysts (Fe-CN) were synthesized by using molten salts and reflux method. They were characterized by various techniques, including XPS, IR, SEM, UV-Vis, EIS, and PL. To evaluate the photocatalytic reduction of U(VI) under visible light irradiation, various influencing factors were systematically investigated. The results showed that all Fe-CN samples exhibited significantly greater photocatalytic activity than pristine g-C3N4. The optimum Fe-CN photo catalyst with an Fe:C3N4 molar ratio of 1: 10.6 (Fe-CN-3) had the highest photocatalytic performance with a photocatalytic reduction efficiency of U(VI) that reached 96% after 240 min irradiation. Fe-CN-3 presented good reusability, demonstrating its promising applications for treating radioactive contaminants.

Automated summary

Fe-doped graphitic carbon nitride photocatalysts were successfully synthesized and demonstrated to have high photocatalytic activity and efficiency in treating uranium-containing waste water. The optimal catalyst Fe-CN-3 showed excellent reusability and treatment performance.