Magnetic metal organic frameworks/graphene oxide adsorbent for the removal of U(VI) from aqueous solution

A well-defined magnetic metal organic frameworks (MOFs)/graphene oxide (Fe3O4@HKUST-1/GO) consisting of magnetic Fe3O4 nanoparticles, HKUST-1 nanocrystal and GO was synthesized through a simple and environmentally friendly approach. Characterizations of Fe3O4@HKUST-1/GO adsorbing U(VI) with high-resolution transmission electron microscopy suggested that the Fe3O4@HKUST-1/GO possessed good stability. The introduction of GO enhanced the ability of particles to uptake U(VI) from aqueous solution. The effects of solution pH, contact time and temperature on U(VI) adsorption were systematically tested by intermittent experiments. The adsorption process can be better described by the Langmuir model and the pseudo-second-order kinetic model. The results showed that the Fe3O4@HKUST-1/GO exhibited good adsorption capacity towards U(VI) at the initial solution pH value of 4.0 and T = 318 K. The X-ray photoelectron spectroscopy was used to analyze the U(VI) removal mechanism. This work represents the application of Fe3O4@HKUST-1/GO as a novel adsorbent to extract U(VI) from contaminated water.