The extraction of uranium from seawater is essential for the sustainable development of the nuclear industry. Covalent organic frameworks (COFs) exhibit significant potential in uranium extraction from seawater due to...
The extraction of uranium from seawater is essential for the sustainable development of the nuclear industry. Covalent organic frameworks (COFs) exhibit significant potential in uranium extraction from seawater due to their high stability, designability, and large specific surface area. Herein, a vinyl-decorated covalent organic framework, designated as COF-IHEP5, was synthesized through acid-catalyzed solvothermal method. COF-IHEP5-COOH was constructed by post-modification strategy through the "thiol-ene" click reaction, where COF-IHEP-COOH contains hydrazone-carbonyl and flexible carboxylic acid chelating sites on pore wall. This modification facilitates synergistic adsorption of uranium by utilizing a "nano trap" that is embedded within the COF framework. The maximum adsorption capacity of the post-modified COF-IHEP5-COOH for UO₂²⁺ has reached 543.8 mg/g, representing a 1.5-fold increase compared to the unmodified COF-IHEP5. Additionally, COF-IHEP5-COOH demonstrates an extraction efficiency of approximately 80% for uranium from spiked natural seawater, featuring 4.5 times higher selectivity than vanadium. The DFT calculation results show that the adsorption of uranium orginated from the synergistic coordination of the skeleton in COF-IHEP5-COOH and carboxyl group on the side arm. This research highlights the remarkable potential of pore surface engineering in customizing active adsorption sites and offers new insights for the design of functionalized uranium adsorbents with superior binding affinity and adsorption capacities.
The experimental determination of the superconducting transition requires the observation of the emergence of zero-resistance and perfect diamagnetism state. Based on the close relationship between superconducting tra...
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A poly vinyl alcohol（PVA） scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The streng...
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A poly vinyl alcohol（PVA） scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The strengthened porous PVA exhibits aligned interconnected porous structures and shows a significant enhancement in tensile testing and compression strength testing.
Recently,the issue of cancer has attracted extensive *** diagnosis and timely therapy are important for cancer *** lots of advanced fluorescent probes have been applied to cancer ***,the further development of these p...
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Recently,the issue of cancer has attracted extensive *** diagnosis and timely therapy are important for cancer *** lots of advanced fluorescent probes have been applied to cancer ***,the further development of these probes is limited by the disadvantages of poor targeting,weak sensitivity and ***,the emergence of biomolecule-conjugated fluorescent probes with aggregationinduced emission properties has taken innovative impetus to the cancer *** review summarizes the rational fabrication and biomedical applications of biomolecule-conjugated A1E luminogens(AIEgens)based on"click reaction"over the past *** the meantime,the challenges of biomolecule-conjugated AIEgens in the field of biomedicine are also discussed.
Heterogeneous photocatalysis has long been considered to be one of the most promising approaches to tackling the myriad environmental ***,there are still many challenges for designing efficient and cost-effective phot...
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Heterogeneous photocatalysis has long been considered to be one of the most promising approaches to tackling the myriad environmental ***,there are still many challenges for designing efficient and cost-effective photocatalysts and photocatalytic degradation systems for application in practical environmental *** this review,we first systematically introduced the fundamental principles on the photocatalytic pollutant ***,the important considerations in the design of photocatalytic degradation systems are carefully addressed,including charge carrier dynamics,catalytic selectivity,photocatalyst stability,pollutant adsorption and photodegradation ***,the underlying mechanisms are thoroughly reviewed,including investigation of oxygen reduction properties and identification of reactive oxygen species and key *** review in environmental photocatalysis may inspire exciting new directions and methods for designing,fabricating and evaluating photocatalytic degradation systems for better environmental remediation and possibly other relevant fields,such as photocatalytic disinfection,water oxidation,and selective organic transformations.
The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those ...
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The selective laser melting(SLM) method has a great potential for fabricating injection mold with complex structure. However, the microstructure and performance of the SLM molds show significantly di erent from those manufac?tured by traditional technologies. In this study, the microstructure, hardness and especially corrosion behavior of the samples fabricated by SLM and casting were investigated. The XRD results exhibit that the γ?Fe phase is only obtained in the SLM parts, and the α?Fe peak slightly moves to low di raction angle compared with casting counterparts. Due to the rapid cooling rate, the SLM samples have fine cellular microstructures while the casting ones have coarse grains with obvious elements segregation. Besides, the SLM samples show anisotropy, hardness of side view and top view are 48.73 and 50.31 HRC respectively, which are 20% higher than that of casting ones. Corrosion results show that the SLM samples have the better anti?corrosion resistance(in a 6% FeCl3 solution for 48 h) but the deeper corrosion pits than casting ones. Finally, the performance of the SLM molds could meet the requirement of injecting production. Moreover, the molds especially present a significant decrease(20%) of cooling time and increases of cooling uniform?ity due to the customized conformal cooling channels.
The local charge distributions of different shape graphene sheets are investigated by using the quantum calculations. It is found that the charge distribution on carbon atom is not uniform, strongly depending on its p...
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The local charge distributions of different shape graphene sheets are investigated by using the quantum calculations. It is found that the charge distribution on carbon atom is not uniform, strongly depending on its position in the graphene and its local atomic environment condition. The symmetrical characteristic and geometrical structures of graphene also have an important influence on the charge distribution. The charges of atom at the graphene edge are strongly related to their surrounding bonds. It is found that the charges of double-bonded atom at the zigzag edge are closely related to the bond angle, but the charges of double-bonded atom at the armchair edge are mainly influenced by the area of triangle. The charges of triple-bonded atom at the edge are mainly affected by the standard deviation of the length of the associated triple bonds.
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