Interlayer spacing adjusted zirconium phosphate with 2D ion channels for highly efficient removal of uranium contamination in radioactive effluent

The efficient fix of environmental uranium contaminations from radioactive effluents is of great practical significance. However, the weaknesses of currently available uranium adsorbents, including slow adsorption speed, low adsorption capacity, and lack of environmental tolerance, limit their practical application. Herein, an interlayer spacing adjusted 2D adsorbent, named as ZrP@1,8-Diaminoctane, is fabricated. With an ultra-low dosage of 0.06 g/L, ZrP@1,8-Diaminoctane exhibits a high and fast uranium removal performance of 97.1% within two minutes. Attributing to the fully exposure of the interlayer functional sites, ZrP@1,8-Diaminoctane achieves a high uranium adsorption capacity of 351.41 mg/g, which is increased by 13.12 times compared with that of the original alpha-ZrP. Furthermore, the binding of uranium by ZrP@1,8-Diaminoctane happens by tightly chemical adsorption and no observable release of uranium is detected after soaking the uranium-loaded ZrP@1,8-Diaminoctane in seawater and simulated groundwater for 30 days. The analysis of the binding mechanism by EXAFS reveals that uranium is bound by coordinating with six oxygen atoms from the phosphate groups, which empower the adsorbent with high binding affinity. Attributing to all above advantages, ZrP@1,8Diaminoctane would be a promising adsorbent for fixing of uranium contaminations in the environment.