Graphene oxide/graphitic carbon nitride/polyamide oxime nanofibers for adsorption and photocatalytic reduction of uranium from seawater

The advancement of the extraction of uranium(VI) (U(VI)) from seawater holds significant strategic importance for the sustainable progression of nuclear energy. In this study, the photocatalyst heterojunction of graphene oxide/graphitic carbon nitride (GO/g-C3N4) was encapsulated by the spinning of fiber to obtain a graphene oxide/graphitic carbon nitride/polyamide oxime (GO/g-C3N4/PAO) film with adsorption and photoreduction ability toward U(VI). The enhanced adsorption capacity of the GO/g-C3N4/PAO nanofiber was achieved through the synergistic effects of the aminoxime group in PAO and the photocatalytic performance of GO/g-C3N4. The GO/g-C3N4/PAO composite exhibited an adsorption capacity of 190.7 mg g−1 (pH = 6, t = 600 min, C0 = 99.9 mg L−1, and m/v = 0.5 g L−1) under light conditions. GO/g-C3N4/PAO showed good recycling reproducibility following five cycles of adsorption. After 30 days of adsorption in natural seawater, the adsorption capacity of GO/g-C3N4/PAO for U(VI) was 10.39 mg g−1, representing a 38.6% increase compared to its performance in the absence of light. The favorable adsorption characteristics exhibited by the GO/g-C3N4/PAO composite suggest its potential as a viable option for the extraction of uranium from seawater.