Achieving efficient photocatalytic uranium extraction within a record short period of 3 min by Up-conversion erbium doped ZnO nanosheets

As an important strategic resource and environmental pollutant, uranium has high toxicity and economic value. Photocatalytic reduction of soluble hexavalent uranium (U(VI)) is a green and economic method to achieve uranium extraction, whereas the reported photocatalyst commonly requires a long period of > 1 h to reach a high extraction efficiency (>90%). Herein, we reported the ultrafast photocatalytic uranium extraction by up-conversion Er doped ZnO nanosheets. In the initial U(VI) concentration of 200 mg/L, the Er doped ZnO with 4% doping level (Er-0.04-ZnO) nanosheets achieved 91.8% within 3 min, which was at least a magnitude shorter relative to ever-reported materials. The Er-0.04-ZnO nanosheets reached a high removal efficiency of 96.1% in 10 min, with a considerable U(VI) extraction capacity of 3036 mg/g. The mechanistic study showed that the Er doping induced the up-conversion properties and increases the carrier density, thus enhancing the light adsorption and accelerating the U(VI) extraction.

Automated summary

As an important strategic resource and environmental pollutant, uranium has high toxicity and economic value. This study reports the ultrafast photocatalytic uranium extraction using up-conversion Er doped ZnO nanosheets. The Er-0.04-ZnO nanosheets achieved a high extraction efficiency within a much shorter time compared to previous materials, benefiting from the up-conversion properties induced by Er doping.