pH-Dependent Dual-Mode Detection toward Uranium by a Zinc-Tetraphenylethylene Fluorescent Metal–Organic Framework

Abstract

An interpenetrated tetraphenylethylene-based fluorescent metal−organic framework (ECUT-180) with exceptional sensitivity, excellent selectivity, and fast response (less than 30 s) toward uranium was successfully prepared. Especially, in the prescence of uranyl, ECUT-180 displays significant fluorescence turn-on under pH 2−3, while fluorescence turn-off under pH 4−8. The corresponding detection limits were determined to be 2.92 ppb at pH 2 and 0.86 ppb at pH 8, both of which are lower than the average uranium content (3.3 ppb) in seawater. Mechanism investigation reveals that the fluorescence enhancement on the strong acid condition can be assigned to uranium adsorption, while the quenching is caused by the resonance energy transfer.

Stabilization of Uranium in Acid Ore Wastewater through Hydrothermal Mineralization-Induced Crystallization

“…To the best of our knowledge, there are many methods for treating the U­(VI) wastewater including reduction of U­(VI) into U­(IV) by photocatalytic , and zerovalent iron, − adsorption of U­(VI) by porous materials, − and precipitation of U­(VI) into precipitates. − Among them, the reduced U­(IV) could be possibly reoxidized into U­(VI), while the adsorbed U­(VI) could be desorbed due to the change in the geochemical conditions. They performed the potential migration and leaching risk .…”