Boosting Simultaneous Uranium Decorporation and Reactive Oxygen Species Scavenging Efficiency by Lacunary Polyoxometalates.

The chemical toxicity and the oxidative stress induced by the internal exposure of uranium is responsible for the long-term adverse effect of in vivo contamination of uranium. An agent with simultaneous removal capability of uranium and excess reactive oxygen species (ROS) is highly desired. Herein, the lacunary Keggin-type polyoxometalate (POM) is demonstrated to selectively bind with uranyl ions in the presence of excess essential divalent ions and exhibits a compelling ROS scavenging efficiency of 78.8%. In vivo uranium decorporation assays illustrate the uranium sequestration efficiencies of 74.0%, 49.4%, and 37.1% from kidneys by prophylactic, prompt, and delayed administration of lacunary POM solution, respectively. The superior ROS quenching and uranium removal performance in comparison with all reported bifunctional agents endow lacunary polyoxometalates as novel agents to effectively protect people from injuries caused by the internal exposure of actinides.

Hinokitiol, an Advanced Bidentate Ligand for Uranyl Decorporation.

Despite the critical role actinide decorporation agents play in the emergency treatment of people in nuclear accidents and other scenarios that may cause internal contamination of actinides, new ligands have seldom been reported in recent decades because the current inventory has been limited to only a handful of functional groups. Therefore, new functional groups are always being urgently sought for the introduction of advanced actinide decorporation agents. Herein, a tropolone derivative, 2-hydroxy-6-(propan-2-yl)cyclohepta-2,4,6-trien-1-one (Hinokitiol or Hino), is proposed to be a promising candidate for this purpose by virtue of its well-demonstrated high membrane permeability and high affinity for metal ions. The coordination stoichiometry of Hino with uranyl is demonstrated to be 3:1 both in an aqueous solution (pH 7.4) and in the solid state. The results of a liquid-liquid extraction experiment further show that Hino exhibits strong chelating ability and selectivity toward uranyl over biological essential metal ions (i.e., Mn2+, Zn2+, Co2+, and Ni2+) with an extraction efficiency of >90.0%. The in vivo uranyl removal efficacies of Hino in kidneys and bone of mice are demonstrated to be 67.0% and 32.3%, respectively. On the basis of the observations described above, it is highly possible that further modification of Hino will lead to a large family of multidentate agents with enhanced uranyl decorporation ability.

Natural polymer konjac glucomannan mediated assembly of graphene oxide as versatile sponges for water pollution control.

Three-dimensional network structure of konjac glucomannan/graphene oxide (KGM/GO) sponges was successfully prepared by ice template method. The KGM/GO sponges was rich in functional groups, negatively charged under pH 2 to 10. Batch adsorption experiment was conducted to investigate the adsorption performance of the as-prepared KGM/GO sponges for organic dye (malachite green (MG)) and radionuclide (uranium U(Ⅵ)). The results showed that the maximum adsorption capacities of KGM/GO sponges were 266.97, 189.96 mg/g for U(Ⅵ) and MG, respectively. Moreover, the KGM/GO sponges exhibited an excellent selectivity for capturing U(Ⅵ) in multi-ion system. The adsorption process was fitted better to pseudo-second order model, while adsorption isotherms for these pollutants were well matched up to Langmuir models. In addition, KGM/GO sponges can be easily separated from the aqueous solution and could be effectively reused for 5 times without obvious loss in adsorption performance. The advantages of eco-friendliness, low cost, simple preparation process, controllable shape and size, as well as high adsorption capacities for MG and U(Ⅵ), suggested that KGM/GO sponges promising in water pollution control.