Separation and Extraction of Uranium from Leach Liquor Containing Uranium and Molybdenum by Solvent Extraction with LIX 622N

The leach liquor (0.5 g/L Mo, 0.05 g/L U) obtained from the leaching process of molybdenum-uranium ore material was treated using solvent extraction to recover U(VI) by LIX 622N, which is a salicylaldoxime derivative. The influence of various basic variables such as pH, concentration of LIX 622N, temperature, different stripping reagents, phase ratio, and diluents was examined. Using 10% LIX 622N with the aqueous solution of equilibrium pH 6.0 and a phase ratio organic phase:aqueous phase (O:A) = 1:1, a two-stage McCabe-Thiele plot was constructed, which showed 99.9% of U extraction with no co-extraction of molybdenum. This was confirmed by a 6-cycle counter current simulation (CCS) study. The obtained data of temperature on the extraction of uranium showed that the extraction process is exothermic with enthalpy change of ?20.949 kJ mol^?1. The stripping of U(VI) was quantitative using 4 M H₂SO₄. The stable complex UO₂(HSO₄)R_org formed during extraction, which supports the cation exchange mechanism, and was confirmed by FTIR spectral analysis.      

Regenerable Covalent Organic Frameworks for Photo-enhanced Uranium Adsorption from Seawater

Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA-TN-AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA-TN-AO with a high anti-biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed U^VI to insoluble U^IV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA-TN-AO to uranium in seawater reaches 6.07 mg g⁻¹, which is 1.33 times of that in dark. The NDA-TN-AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.     

N—正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学研究

采用上升单液滴法研究了Ｎ－正辛基己内酰胺从硝酸介质中萃取铀（Ⅵ）的动力学，得出Ｕ（Ⅵ）的萃取速率与水相中铀浓度的１次方成正比，与温度（１０－４５℃）无关；萃合物向有机相的扩散为萃取过程的速控步骤。     

Enhanced Cytosolic Delivery and Release of CRISPR/Cas9 by Black Phosphorus Nanosheets for Genome Editing

A biodegradable two‐dimensional (2D) delivery platform based on loading black phosphorus nanosheets (BPs) with Cas9 ribonucleoprotein engineered with three nuclear localization signals (NLSs) at C terminus (Cas9N3) is successfully established. The Cas9N3‐BPs enter cells effectively via membrane penetration and endocytosis pathways, followed by a BPs biodegradation‐associated endosomal escape and cytosolic releases of the loaded Cas9N3 complexes. The Cas9N3‐BPs thus provide efficient genome editing and gene silencing in vitro and in vivo at a relatively low dose as compared with other nanoparticle‐based delivery platforms. This biodegradable 2D delivery platform offers a versatile cytosolic delivery approach for CRISPR/Cas9 ribonucleoprotein and other bioactive macromolecules for biomedical applications.     

Stabilization of Black Phosphorus by Sonication-Assisted Simultaneous Exfoliation and Functionalization

Black phosphorus (BP) has extraordinary properties, but its ambient instability remains a critical challenge. Functionalization has been employed to overcome the sensitivity of BP to ambient conditions while preserving its properties. Herein, a simultaneous exfoliation–functionalization process is reported that functionalizes BP flakes during exfoliation and thus provides increased protection, which can be attributed to minimal exposure of the flakes to ambient oxygen and water. A tetrabutylammonium salt was employed for intercalation of BP, resulting in the formation of flakes with large lateral dimensions. The addition of an aryl iodide or an aryl iodonium salt to the exfoliation solvent creates a scalable strategy for the production of functionalized few-layer BP flakes. The ambient stability of functionalized BP was prolonged to a period of one week, as revealed by STEM, AFM, and X-ray photoelectron spectroscopy.     

Regenerable Covalent Organic Frameworks for Photo‐enhanced Uranium Adsorption from Seawater

Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed U^VI to insoluble U^IV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA‐TN‐AO to uranium in seawater reaches 6.07 mg g^?1, which is 1.33 times of that in dark. The NDA‐TN‐AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.     

Spidroin-Inspired,High-Strength,Loofah-Shaped Protein Fiber for Capturing Uranium from Seawater

The unique three-dimensional structure of spidrion determines the outstanding mechanical properties of the spider silk fiber. Inspired by the similarity of the three-dimensional structure of superb-uranyl binding protein (SUP) to that of spidroin, a dual-SUP (DSUP) chimeric protein fiber with high tensile strength is designed. The DSUP hydrogel fiber exhibits a loofah-shape structure by the cross-interaction of the protein nanofiber. Full exposure of abundant functional uranyl-binding sites in the stretchable loofah-shape hydrogel protein fiber give the DSUP fiber a groundbreaking uranium extraction capacity of 17.45 mg g⁻¹ with an ultrashort saturation time of 3 days in natural seawater. This work reports the design of an adsorbent with ultrahigh uranium extraction capacity and explores a strategy for fabricating artificial high-strength functional non-spidroin protein fiber.     

Black Phosphorus Rediscovered: From Bulk Material to Monolayers

Phosphorus is a nonmetal with several allotropes, from the highly reactive white phosphorus to the thermodynamically stable black phosphorus (BP) with a puckered orthorhombic layered structure. The bulk form of BP was first synthesized in 1914, but received little attention until it was rediscovered in 2014 as a member of the new wave of 2D layered nanomaterials. BP can be exfoliated to a single sheet that acts as a semiconductor with a tunable direct band gap, a high carrier mobility at room temperature, and an in-plane anisotropy. The development of BP applications is hampered by surface degradation, thus efforts to achieve effective BP passivation are ongoing, such as its integration in van der Waals heterostructures. BP has been tested as a novel nanomaterial in batteries, transistors, sensors, and photonics. This Review begins with the origin of the BP story, following the path from a bulk material to modern few/single layers. The physical and chemical properties are summarized, and the state-of-the-art of BP applications highlighted.     

Electrospun Silk Fibroin/Polylactic-co-glycolic Acid/Black Phosphorus Nanosheets Nanofibrous Membrane with Photothermal Therapy Potential for Cancer

Photothermal therapy is a promising treating method for cancers since it is safe and easily controllable. Black phosphorus (BP) nanosheets have drawn tremendous attention as a novel biodegradable thermotherapy material, owing to their excellent biocompatibility and photothermal properties. In this study, silk fibroin (SF) was used to exfoliate BP with long-term stability and good solution-processability. Then, the prepared BP@SF was introduced into fibrous membranes by electrospinning, together with SF and polylactic-co-glycolic acid (PLGA). The SF/PLGA/BP@SF membranes had relatively smooth and even fibers and the maximum stress was 2.92 MPa. Most importantly, the SF/PLGA/BP@SF membranes exhibited excellent photothermal properties, which could be controlled by the BP@SF content and near infrared (NIR) light power. The temperature of SF/PLGA/BP@SF composite membrane was increased by 15.26 °C under NIR (808 nm, 2.5 W/cm²) irradiation for 10 min. The photothermal property of SF/PLGA/BP@SF membranes significantly killed the HepG2 cancer cells in vitro, indicating its good potential for application in local treatment of cancer.     

Rational Utilization of Black Phosphorus Nanosheets to Enhance Palladium-Mediated Bioorthogonal Catalytic Activity for Activation of Therapeutics

Pd-catalyzed chemistry has played a significant role in the growing subfield of bioorthogonal catalysis. However, rationally designing Pd nanocatalysts that show outstanding catalytic activity and good biocompatibility poses a great challenge. Herein, we propose an innovative strategy through exploiting black phosphorous nanosheets (BPNSs) to enhance Pd-mediated bioorthogonal catalytic activity. Firstly, the electron-donor properties of BPNSs enable in situ growth of Pd nanoparticles (PdNPs) on it. Meanwhile, due to the superb capability of reducing Pd^II, BPNSs can act as hard nucleophiles to accelerate the transmetallation in the decaging reaction process. Secondly, the lone pair electrons of BPNSs can firmly anchor PdNPs on their surface via Pd−P bonds. This design endows Pd/BP with the capability to retard tumor growth by activating prodrugs. This work proposes new insights into the design of heterogeneous transition-metal catalysts (TMCs) for bioorthogonal catalysis.     

伯胺N~1~9~2~3萃取硫酸铀酰的机理研究

研究了伯胺N~1~9~2~3的正庚烷溶液从硫酸介质中萃取硫酸铀酰的机理。认为伯胺N~1~9~2~3的硫酸盐在有机相中形成了反向胶束(或胶团),并由红外光谱和透射电镜佐证。伯胺N~1~9~2~3和铀酰形成的萃合物主要存在于反向胶束准相中。可以较好地解释用斜率法无法解释的实验事实。     

Effects of Impregnated Amidophosphonate Ligand Concentration on the Uranium Extraction Behavior of Mesoporous Silica

A series of solid-phase uranium extractants were prepared by post-synthesis impregnation of a mesoporous silica support previously functionalized with octyl chains by direct silanization. Five materials were synthesized with 0, 0.2, 0.3, 0.4 and 0.5 mmol of the amidophosphonate ligand DEHCEBP per gram of functionalized solid, and the effect of the ligand concentration on the uranium extraction efficiency and selectivity of the materials was investigated. Nitrogen adsorption–desorption data show that with increasing ligand loadings, the specific surface area and average pore volume decrease as the amidophosphonate ligand fills first the micropores and then the mesopores of the support. Acidic uranium solutions with a high sulfate content were used to replicate the conditions in ore treatment leaching solutions. Considering the extraction kinetics, the equilibration time was found to increase with the ligand concentration, which can be explained by the clogging of micropores and the multilayer arrangement of the DEHCEBP molecules in the materials with their highest ligand contents. The fact that the equilibrium ligand/uranium ratio is about 2 mol/mol regardless of the ligand concentration in the material suggests that all the ligand molecules remain accessible for extraction. The maximum uranium extraction capacities ranged from 30 mg∙g⁻¹ at 0.2 mmol∙g⁻¹ DEHCEBP to 54 mg∙g⁻¹ in the material with 0.5 mmol∙g⁻¹ DEHCEBP. These materials could therefore potentially be used as solid-phase uranium extractants in acidic solutions with high sulfate concentrations.     

水环境中磷的灰化法提取

对多种无机磷和有机磷化合物进行了实验，尝试不少盐试剂（本文称之为灰化助剂），研究它们在灰化法提取磷中的作用效果和机制。我们发现，许多无机磷和有机磷化合物加入MgSO4灼烧后残渣中的磷并不完全回收。而MgCl、Mg(Ac)2、CaCl2等助剂，即都胡使灼烧后的磷易于完全回收。我们认为，在利用目前已被广泛应用的MgSO4高温灰化法分析水体中的颗粒磷和总磷或有机体中的磷时，应当用MgCl2取代MgSO4作为灰化助剂。而对于硫酸盐含量低的样品，CaCl2同样是很有效的灰化助剂。尽管Mg（NO3）2也是高效的灰化辅助剂，但其应用存在危险性及较多的手工操作等缺陷，且还存在MgSO4的盐效应问题，这限制了其广泛应用。本研究认为，如果沉积物中加入MgCl2后灰化，用0.2mol/L Hcl于80℃浸提残渣0.5h足以达到分析目的。     

Mediated Drug Release from Nanovehicles by Black Phosphorus Quantum Dots for Efficient Therapy of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an intractable disease involving a sticky mucus layer and nanoagents with mucus-penetrating capability offer a new way to deliver drugs. However, drug release from nanovehicles requires optimization to enhance the therapeutic effects of COPD therapy. Herein, black phosphorus quantum dots (BPQDs) are combined with PEGylated chitosan nanospheres containing the antibiotic amikacin (termed PEG@CS/BPQDs-AM NPs). As a drug-delivery system, the hydrophilicity of PEG and positive charge of CS facilitate the penetration of nanovehicles through the mucus layer. The nanovehicles then adhere to the mucous membrane. Furthermore, the BPQDs degrade rapidly into nontoxic PO₄³⁻ and acidic H⁺, thereby promoting the dissociation of PEGylated CS nanospheres, accelerating the release of AM, decreasing the vitality of biofilms for ease of eradication. Our results reveal that drug delivery mediated by BPQDs is a feasible and desirable strategy for precision medicine and promising for the clinical therapy of COPD.     

Spidroin‐Inspired,High‐Strength,Loofah‐Shaped Protein Fiber for Capturing Uranium from Seawater

The unique three‐dimensional structure of spidrion determines the outstanding mechanical properties of the spider silk fiber. Inspired by the similarity of the three‐dimensional structure of superb‐uranyl binding protein (SUP) to that of spidroin, a dual‐SUP (DSUP) chimeric protein fiber with high tensile strength is designed. The DSUP hydrogel fiber exhibits a loofah‐shape structure by the cross‐interaction of the protein nanofiber. Full exposure of abundant functional uranyl‐binding sites in the stretchable loofah‐shape hydrogel protein fiber give the DSUP fiber a groundbreaking uranium extraction capacity of 17.45 mg g^?1 with an ultrashort saturation time of 3 days in natural seawater. This work reports the design of an adsorbent with ultrahigh uranium extraction capacity and explores a strategy for fabricating artificial high‐strength functional non‐spidroin protein fiber.     

Insights into the Mechanism of Extraction of Uranium (VI) from Nitric Acid Solution into an Ionic Liquid by using Tri‐n‐butyl phosphate

We present new results on the liquid–liquid extraction of uranium (VI) from a nitric acid aqueous phase into a tri‐n‐butyl phosphate/1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (TBP/[C₄mim][Tf₂N]) phase. The individual solubilities of the ionic‐liquid ions in the upper part of the biphasic system are measured over the whole acidic range and as a function of the TBP concentration. New insights into the extraction mechanism are obtained through the in situ characterization of the extracted uranyl complexes by coupling UV/Vis and extended X‐ray absorption fine structure (EXAFS) spectroscopy. We propose a chemical model to explain uranium (VI) extraction that describes the data through a fit of the uranyl distribution ratio D_U. In this model, at low acid concentrations uranium (VI) is extracted as the cationic complex [UO₂(TBP)₂]²⁺, by an exchange with one proton and one C₄mim⁺. At high acid concentrations, the extraction proceeds through a cationic exchange between [UO₂(NO₃)(HNO₃)(TBP)₂]⁺ and one C₄mim⁺. As a consequence of this mechanism, the variation of D_U as a function of TBP concentration depends on the C₄mim⁺ concentration in the aqueous phase. This explains why noninteger values are often derived by analysis of D_U versus [TBP] plots to determine the number of TBP molecules involved in the extraction of uranyl in an ionic‐liquid phase.     

Extraction of uranium(IV) and uranium(VI) by primary and tertiary-amines from sulphate solutions

In developing a method for possible low level isotopic enrichment, which uses to advantage the equilibrium isotope effect observed during U(1V)-U(VI) electron exchange reaction in sulphate solutions, details of a solvent extraction process involving high concentration of a mixture of U(IV) and U(VI) and at low acid concentrations, are described. The extraction behaviour of uranium under these conditions is discussed. During the extraction with amines, U(IV) tended to get oxidised in sulphate solutions.