Rapid and efficient uranium(VI) capture by phytic acid/polyaniline/FeOOH composites.

Uranium plays an indispensable role in nuclear energy, but there are limited land resources to meet the ever growing demand; therefore, a need exists to develop efficient materials for capturing uranium from water. Herein, we synthesize a promising adsorbent of phytic acid/polyaniline/FeOOH composites (PA/PANI/FeOOH) by oxidative polymerization. Phytic acid, acting asa gelator and dopant, plays an important role in the formation of polyaniline (PANI). The PA/PANI/FeOOH exhibites high adsorption capacity (qm=555.8mgg-1, T=298K), rapid adsorption rate (within 5min), excellent selectivity and cyclic stability. In addition, the results show that the adsorption isotherm is well fitted to the Langmuir isotherm model, and the adsorption kinetics agree with a pseudo-second order model. XPS analysis indicates that the removal of uranium is mainly attributed to abundant amine and imine groups on the surface of PA/PANI/FeOOH. Importantly, the removal of uranium from low concentrations of simulated seawater is highly efficient with a removal rate exceeding 92%. From our study, superior adsorption capacities, along with a low-cost, environmentally friendly and facile synthesis, reveal PA/PANI/FeOOH asa promising material for uranium capture.

Efficient removal of uranium(vi) from simulated seawater using amidoximated polyacrylonitrile/FeOOH composites.

The ability to recover uranium, an important nuclear fuel, from seawater provides the potential for long-term sustainable fuel supply for nuclear energy. In this work, novel amidoximated polyacrylonitrile/FeOOH (FeOOH-APAN) composites were synthesized and characterized by CHN analysis, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). In batch adsorption experiments, a variety of parameters were investigated in detail. The FeOOH-APAN composites exhibit high adsorption capacities (qL = 980.39 mg g-1, T = 298 K), superior to many other materials. In addition, they possess large Kd values (>104 mL g-1 at 25-400 mg L-1 U concentration), high removal rates (∼95% at 25-300 mg L-1, and ∼90% for ppb level simulated seawater), excellent selectivity and rapid capturing rates for uranium. XPS analysis shows that the removal of uranium is mainly related to amidoxime groups, involving the interaction with oxime oxygen and oxime nitrogen. In this paper, a more dominant binding mode is proposed, namely η2 coordination.