Amidoxime-grafted cotton fibers with anti-microbial sludge for efficient uranium recovery.

Uranium as a nuclear fuel, its source and aftertreatment has been a hot topic of debate for developers. In this paper, amidoxime and guanidino-modified cotton fibers (DC-AO-PHMG) were synthesized by the two-step functionalization approach, which exhibited remarkable antimicrobial and high uranium recovery property. Adsorption tests revealed that DC-AO-PHMG had excellent selectivity and anti-interference properties, the maximum adsorption capacity of 609.75 mg/g. More than 85 % adsorption capacity could still be kept after 10 adsorption-desorption cycles, and it conformed to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model as a spontaneous heat-absorbing chemical monolayer process. FT-IR, EDS and XPS analyses speculated that the amidoxime and amino synergistically increased the uranium uptake. The inhibitory activities of DC-AO-PHMG against three aquatic bacteria, BEY, BEL (from Yellow River water and lake bottom silt, respectively) and B. subtilis were significantly stronger, and the uranium adsorption was not impacted by the high bacteria content. Most importantly, DC-AO-PHMG removed up to 94 % of uranium in simulated seawater and extracted up to 4.65 mg/g of uranium from Salt Lake water, which demonstrated its great potential in the field of uranium resource recovery.

Metal-organic frame material encapsulated Rhodamine 6G: A highly sensitive fluorescence sensing platform for the detection of picric acid contaminants in water.

As a water pollutant with excellent solubility, 2,4,6-trinitrophenol (also known as picric acid, PA) poses a potential threat to the natural environment and human health, so it is crucial important to detect PA in water. In this study, a novel composite material (MIL-53(Al)@R6G) was successfully synthesized by encapsulating Rhodamine 6G into a metal-organic frame material, which was used for fluorescence detection of picric acid (PA) in water. The composite exhibits bright yellow fluorescence emission with a fluorescence quantum yield of 58.23 %. In the process of PA detection, the composite has excellent selectivity and anti-interference performance, and PA can significantly quench the fluorescence intensity of MIL-53(Al)@R6G. MIL-53(Al)@R6G has the advantages of fast detection time (20 s), wide linear range (1-100 µM) and low detection limit (4.8 nM). In addition, MIL-53(Al)@R6G has demonstrated its potential for the detection of PA in environmental water samples with satisfactory results.

Synthesis Strategies, Preparation Methods, and Applications of Chiral Metal-Organic Frameworks.

Chiral Metal-Organic Frameworks (CMOFs) is a kind of material with great application value in recent years. Formed by the coordination of metal ions or metal clusters with organic ligands. It has ordered and adjustable pores, multi-dimensional network structure, large specific surface area and excellent adsorption properties. This material structure combines the properties of metal-organic frameworks (MOFs) with the chiral properties of chiral molecules. It has great advantages in catalysis, adsorption, separation and other fields. Therefore, it has a wide range of applications in chemistry, biology, medicine and materials science. In this paper, various synthesis strategies and preparation methods of chiral metal-organic frameworks are reviewed from different perspectives, and the advantages of each method are analyzed. In addition, the applications of chiral metal-organic framework materials in enantiomer recognition and separation, circular polarization luminescence and asymmetric catalysis are systematically summarized, and the corresponding mechanisms are discussed. Finally, the challenges and prospects of the development of chiral metal-organic frame materials are analyzed in detail.

Zirconium-based metal-organic framework encapsulated dye molecules: An excellent sensing platform for sensitive detection of Cu2+ in aqueous environments.

Residual heavy metal ions in water pose a major hazard to ecology as well as human health, and Cu2+, as the most common heavy metal ion in water bodies, can cause a variety of diseases in human beings with prolonged exposure, therefore, a rational sensing platform is needed for the specific detection of Cu2+. In this work, based on the solvothermal method, we successfully prepared the composite UIO-66@FS by encapsulating the dye fluorescein sodium molecule (FS) with a metal-organic framework material (UIO-66). The composite material has bright fluorescence emission properties with a fluorescence quantum yield of 62.03 %, and the composite material has been used to construct a fluorescence sensing platform for detecting the heavy metal Cu2+ in the aqueous environment. The fluorescence of UIO-66@FS can be greatly quenched by Cu2+, which is visible to the naked eye under UV lamp. The sensing platform is able to withstand environmental interference and has the advantages of high selectivity, excellent sensitivity, fast response, wide linear range (2.5 µM-500 µM), and low detection limit (0.246 µM) in the fluorescence quenching detection of Cu2+. In addition, the sensor has been used to detect Cu2+ in real water samples with satisfactory recoveries. Therefore, this sensing probe can be an excellent candidate for Cu2+ detection and has wonderful potential for real water sample detection.