High efficient photoreduction of U(VI) by a new synergistic photocatalyst of Fe3O4 nanoparticle on GO/g-C3N4 composites

In this study, a novel synergistic photocatalyst (Fe 3 O 4 /GO/g-C 3 N 4 composites) were constructed by chemical precipitation of Fe 3 O 4 nanoparticles on surface of GO/g-C 3 N 4 suspension. The characterization results indicated that Fe 3 O 4 /GO/g-C 3 N 4 composites exhibited high efficient separation of photogenerated electron–hole pair, narrow bandgap (∼2.38 eV) and wide absorption range. The incorporation of Fe 3 O 4 significantly increased the photocatalytic performance of GO/g-C 3 N 4 composites due to synergistic effect. More than 90% of U(VI) was photo-reduced by Fe 3 O 4 /GO/g-C 3 N 4 composites within 2 h under visible light irradiation. The trapping experiments and XPS analysis indicated that the photogenerated electrons and superoxide ( ⋅ O 2 $\cdot {\text{O}}_2$ ) radicals are responsible for U(VI) removal. These findings indicated that magnetic g-C 3 N 4 composites can be used as excellent candidates for the high efficient removal of U(VI) in actual environmental cleanup.