The highly efficient photoreduction of U(VI) using triazine-linked covalent organic frameworks

The superior photoreduction of U(VI) under visible light irradiation is one of most attractive way for the sustainable development of nuclear energy, whereas the development of long-term stable, highly photocatalytic performance and low cost photocatalyst remains a challenge owing to the lack of accessible adsorption intensity in the visible light range. Herein, a boron-incorporated triazine-linked 2D covalent organic frameworks with amidoximeylation (B/AO-COF) was fabricated via solvent modulation method. In comparison with COF (0.0049 /min) and AO-COF(0.0102 /min), the large removal rate of B/AO-COF (0.0145 /min) showed the introduction of AO groups accelerated U(VI) removal. The high photocatalytic efficiency (~ 95 % within 1 h) and good stability (< 5 % after 5 recycles) of B/AO-COF under visible light irradiation was attributed to low recombination of photogenerated electron-hole pairs. According to quenching experiments and ESR analysis, photogenerated electrons and superoxide radials played an important role in U(VI) photoreduction. These findings are crucial for the application of B/AO-COF on the highly efficient removal of U(VI) from aqueous solution in actual environmental remediation.