ZIF-67 decorated three-dimensional MXene/GO aerogels for highly selective removal of Uranium

Abstract

In order to cope with the environmental resource problems caused by nuclear pollution and uranium mine wastewater, it is particularly important to develop low-cost, efficient, controllable of uranium adsorption materials. In this work, a novel ZIF-67 decorated three-dimensional oxygen-containing functionalized MXene/GO aerogel (MGZ) was synthesized by a simple two-step process and applied for selective enrich of uranium under different conditions such as pH, contact time, temperature, ionic strength and interfering ions. The batch adsorption experiments revealed that the synthesized MGZ aerogels attained a maximum uranium adsorption capacity of 869.59 mg·g−1 at 298 K and pH 3.0, which was higher than most reported inorganic adsorbents. It also presented outstanding selective adsorption of uranium even in the presence of a high proportion of interfering ions. Furthermore, it still performed satisfactory adsorption capacity of uranium even after five adsorption-desorption cycles. The adsorption mechanism of MGZ on uranium was investigated by FT-IR and XPS. The results showed that there was a synergy between oxygen-containing functional groups and Co-OH, in which oxygen-containing functional groups were the main adsorption functional groups and Co-OH was the main functional group for selectivity. Overall, MGZ could be a promising candidate for the selective and efficient removal of uranium from wastewater.