With the rapid growth of lithium-ion battery waste and increasing demand for critical metals, developing efficient recycling technologies has become crucial for sustainable resource utilization. This study develops an efficient hydrometallurgical process for efficient selective recovery of Li from Co, Mn and Ni in waste NMC lithium-ion battery black mass using a Primene 81-R-based extraction-precipitation system. A systematic investigation first identified HCl (3 mol/L, S:L =1:40, 5 vol% H2O2, 25 degrees C, 60 min) as the optimal lixiviant due to its high affinity for Cl-complexation, enabling nearly 100.0 % metal dissolution for Li, Co, Mn and Ni, compared with H2SO4 and HNO3. The novel extraction system optimized the extraction of Primene 81-R under various conditions (proportion of extractant, pH, O:A, diluent, temperature and time) and achieved effective separation efficiencies of 97.7-100.0 % for Co/Mn/Ni with the order of Co(II) > Mn(II) > Ni(II), while selectively retaining Li in the solution through single-step extraction (10 % Primene 81-R, pH 2, dichloromethane, O:A = 1:1, 25 degrees C). Subsequent precipitation yielded battery-grade Li2CO3 with 99.7 % purity, while multi-stage extraction recovered approximately 97.0 % Li at three stages. Mechanistic studies combining DFT calculations and slope analysis revealed the formation of (RNH3)2 & sdot;MCl4 and RNH3 & sdot;MCl3 (M = Co, Mn, Ni) complexes as the basis for the exceptional transition metal selectivity. This study establishes a technically and economically viable single-step extraction process that simultaneously achieves both high-purity Li recovery with minimal loss and a 30 % higher yield, providing fundamental insights into amine-based mechanisms and practical advancements for sustainable LIB recycling.

Inhibiting the formation of molybdate yellow phase is crucial for the safe and efficient vitrification of high-level liquid waste (HLLW). This work presented the use of nano zero-valent aluminum (nZVAl) to inhibit the formation of molybdate yellow phase during the vitrification of nuclear waste, and thus consequently improve the chemical durability of the glass. The research showed that the addition of nZVAl facilitates the effective dispersion and reduction of molybdenum (Mo), resulting in a substantial improvement of Mo solubility by at least 30%. At 0.5 wt% nZVAl, a remarkable transformation in the morphology of molybdate crystals was observed, transitioning from droplet-shaped to corrugate shapes, effectively mitigating crystal aggregation. In the nZVAl concentration range from 1 to 1.5 wt%, approximately 20% of Mo existed in the forms of Mo(IV) and Mo(V) oxidation states, exhibiting superior solubility within the glass matrix compared to Mo(VI). Beyond the concentration of 2 wt% nZVAl, the complexity of the glass network structure increased due to the presence of [AlO4]- and [AlO6] units, further enhancing Mo solubility and completely eliminating the molybdate yellow phase. This work demonstrated the considerable potential of nZVAl in inhibiting the formation of molybdate yellow phase and lays the foundation for further developing novel glass matrices to immobilize high-Mocontaining HLLW.

The synthesis and utilization of sulfonic acid-functionalized graphitic carbon nitride (C3N4-SO3H) as an effective adsorbent for the removal of Co2+ from aqueous solutions was successful in varying experimental conditions, such as solution pH, adsorption time, and temperature. Kinetic studies revealed that the adsorption process is largely determined by chemical interactions. The experimental data was fitted to Langmuir and Freundlich adsorption isotherm models, and the results showed that Co2+ adsorption onto C3N4-SO3H is a monolayer process. The maximum adsorption capacity of C3N4-SO3H for Co2+ was found to be 247.52 mg g- 1, which is significantly higher than that of unmodified graphitic carbon nitride (g-C3N4). An analysis of thermodynamics proposed that the adsorption process is both spontaneous and endothermic. Furthermore, the adsorption mechanism of Co2+ by C3N4-SO3H was investigated using density functional theory (DFT) calculations, which confirmed that the adsorption process is energetically favorable and spontaneous. The adsorption of Co2+ by C3N4-SO3H was demonstrated to be strong, even under irradiation and high temperatures, thus highlighting its potential for use in the elimination of Co2+ from radioactive wastewater.

Lithium isotope (6Li/7Li) separation is hindered by nearly identical electronic structures and strong solvation. Adsorption strategies based on ligand-ion thermodynamic affinity often struggle to explain the experimentally observed preference for 6Li over 7Li. A crown ether-functionalized covalent organic framework is employed as a representative adsorption system to distinguish the contributions of equilibrium binding and transport processes. Density functional theory calculations show that amino-benzo-15-crown-5 exhibits a slight thermodynamic preference for 7Li, with a lower Gibbs free energy of complexation. Batch experiments reveal an unexpected preference for 6Li adsorption. This behavior arises from its higher zero-point energy and lower mass, which facilitate desolvation and accelerate diffusion, leading to kinetically favored coordination over thermodynamically preferred 7Li. Once coordinated, the small Gibbs free energy difference between isotopes provides limited driving force for ligand exchange, hindering replacement of 6Li by 7Li. These findings support the important role of nonequilibrium transport processes in adsorption-based lithium isotope separation.

The imperative for efficient lithium extraction from salt-lake brines is intensified by the surging global demand for clean energy technologies, with overcoming the intrinsic challenge of Li/Na separation being central to establishing resilient Li supply chains. This study presents a novel HBTA-L2 extraction system that achieves 89.0% Li+ extraction efficiency with a Li+/Na+ separation factor of 62.3 under optimized batch conditions (15 min, pH 11, 0.25 mol & sdot;L-1 HBTA-0.25 mol & sdot;L-1 L2 in toluene, O:A = 5:1, 25 degrees C). The system exhibits strong anti-interference capability against Mg2+, while K+ and oxoanions (particularly SO42-) demonstrate significant inhibitory effects. A washing-stripping process using 1 mol & sdot;L-1 LiCl and 0.5 mol & sdot;L-1 HCl achieved nearly complete Li+ recovery. Mechanistic studies through slope analysis and DFT calculations confirmed the formation of a 2:2:2 complex [Li2 & sdot;2BTA & sdot;2L2]org, revealing that Li's superior coordination stability with oxygen atoms underpins the extraction selectivity. A significant advancement was achieved through a homemade membrane emulsification circulation (MEC) extractor integration, which substantially enhanced process intensification. The MEC extractor achieved 91.7% extraction efficiency with a beta Li/Na of 115 under optimized conditions (5 mu m pore size, 8 & times; 10-5 m3 & sdot;min-1 flow rate), while reducing extraction time and extractant usage more than 60% compared to conventional methods. Through an integrated process of two-stage extraction and multi-stage washing and stripping, high-purity Li2CO3 (99.5%) was obtained and characterized by XRD and SEM-EDS. This work establishes a comprehensive strategy for Li recovery from high Na/Li brines, demonstrating significant potential for practical application through the combination of synergistic extraction and process intensification.

Defects play a pivotal role in enhancing hydrogen production from water radiolysis. To elucidate the influence of defects in boron nitride on radiolytic hydrogen evolution, boron nitride samples with various nitrogen defects (denoted as Nv-BN1, Nv-BN2, and Nv-BN3) were prepared through ball milling, gamma irradiation, and thermal calcination, respectively. Through these operations, samples with different relative densities of three-boron center nitrogen defects (TBC defects) were successfully obtained. Among the synthesized materials, the Nv-BN1 sample with an ultralow solid loading (0.075 wt %) achieved a saturated radiolytic hydrogen yield of 0.65 × 10-7 mol J-1, while Nv-BN2 (0.025 wt %) with higher defect density exhibited an even greater saturated yield of 0.70 × 10-7 mol J-1. In contrast, the calcined Nv-BN3 showed reduced activity due to the passivation of defect sites. Fluorescence experiments revealed elevated levels of both •OH and eaq- in suspensions containing TBC defect samples compared to pure water, suggesting that water molecules at the defect-rich solid-liquid interface undergo enhanced radiolytic dissociation. Notably, the •OH yield was lower than that of eaq-, implying that partial consumption of •OH occurred at electron-deficient boron sites. This hypothesis is supported by X-ray time-resolved in situ infrared spectroscopy, which showed the gradual emergence of a characteristic B-O band near 1190 cm-1 during irradiation, a spectral feature absent in pristine h-BN sample. Complementary density functional theory (DFT) simulations further corroborate this mechanism, suggesting that water molecules preferentially adsorb at TBC defect sites, where the intramolecular O-H bond is weakened, thereby facilitating bond cleavage. Collectively, these results highlight the unique role of TBC defects as catalytic centers that enhance water radiolysis, offering fundamental mechanistic insights into defect-mediated interfacial chemistry and presenting a promising strategy for advancing radiation-driven energy conversion technologies.

Multimetallic pollution in wastewater presents a critical barrier to adsorption-based remediation, as competitive binding among coexisting ions often compromises adsorbent efficiency. Here, we explore the potential of azamacrocycles for multimetal removal in aqueous systems containing coexisting metal ions of comparable sizes. A nitrogen-rich macrocycle-functionalized polymer adsorbent (TA-D380) was synthesized for the simultaneous elimination of Cr3+, Co2+, and Ni2+. Interestingly, TA-D380 displays negligible adsorption toward Co2+ and Ni2+ when present individually, yet a pronounced synergistic adsorption emerges under the coexistence of Cr3+, Co2+, and Ni2+. Notably, the adsorbent exhibits distinct adsorption pathways depending on the metal ion concentration and shows progressively enhanced uptake over repeated cycles, reflecting a dynamic modulation of active binding sites that differs from conventional adsorption behavior. Cross-validation between batch experiments and density functional theory calculations reveals Cr3+ exhibits a pronounced preference for inner-sphere coordination with macrocyclic nitrogen ligands, thereby triggering dynamic reorganization of the interfacial electronic structure. Cr3+-driven modulation of surface potential and ligand field symmetry redefines local coordination landscapes, effectively activating previously inert binding sites and enabling the subsequent adsorption of Co2+ and Ni2+ via a charge-mediated, allosteric-like mechanism. Altogether, these results elucidate the cooperative adsorption of multimetal ions by azamacrocycle-functionalized polymers, providing a basis for advanced heavy metal remediation.

This study investigated the radiolytic behavior of aerated aqueous hydrazine solutions (N2H4) under γ-irradiation, focusing on the effects of various factors such as the initial concentration of hydrazine, absorbed dose, concentration of H3BO3 and ammonia. We measured pH values, the concentrations of N2H4, H2O2, nitrogen oxides (NO2− and NO3−), and gaseous radiolytic products (such as H2 and N2) before and after irradiation. The radiolysis of N2H4 was influenced by its initial concentration and the absorbed dose. When N2H4 remained in the solution, no H2O2 was formed after irradiation, which was attributed to the strong reducing ability of N2H4 and its effective scavenging of O2, ·OH, and H2O2. H3BO3 effectively protected N2H4 from radiolytic decomposition. Variations in the addition of ammonia did not significantly affect the radiolysis process of hydrazine solutions. By collecting the elementary reaction sets of pure water radiolysis and hydrazine radiolysis, we developed a computational model (N2H4–H2O_Rad) for the radiolysis of hydrazine solutions using FACSIMILE simulation software (MCPA Co., Ltd.). The simulation results closely matched the experimental data, demonstrating the validity and accuracy of the computational model.

Cr(III) has attracted considerable attention due to its toxicity and its potential to oxidize into Cr(VI). Boron-doped carbon nitride (BCN) was synthesized, resulting in material with remarkable thermal stability and radiation resistance, specifically designed for adsorption of Cr(III). Characterization and batch experiments indicated BCN2 possesses a considerably large specific surface area and numerous active sites, contributing to its impressive adsorption capacity for Cr(III) at pH 5, which exceeds 1200 mg/g. Kinetic and isotherm studies were investigated and revealed the system follows pseudo-second-order kinetics and fit best with the Freundlich isotherm at high concentrations. Notably, Statistical physics models revealed a notably higher density of the material's adsorption sites. Density functional theory was employed to calculate three structures of BCN combined with Cr(III). Interestingly, the reducing ability of adsorbent for Cr(VI) was explored, offering valuable insights for designing environmentally friendly materials.

Two-dimensional planar pentagonal crystals, long pursued for their geometrically frustrated lattice configurations and emergent quantum phenomena, have remained challenging to realize due to the intrinsic incompatibility of regular pentagons with Euclidean tiling. Here, we unveil 37 dynamically stable binary planar pentagonal monolayers through high-throughput computational screening of 1470 stoichiometric candidates. These materials exhibit room-temperature magnetism, including ferromagnetic (Curie temperature (TC) up to 521 K), antiferromagnetic (Néel temperature (TN) up to 761 K), and altermagnetic (TN = 984 K) ground states, alongside unprecedented electronic states: Dirac semimetals, Dirac half-metal, nodal-loop semimetal, nodal-loop half-metal, and altermagnetic semiconductors (Mn4N2) with giant spin splitting (0.78 eV). The latter achieves pure spin-polarized transport windows (−0.04 to 0.36 eV) and strain-tunable valley splitting (18.2 meV under 4

Coolant selection is intricately linked to the design and type of the nuclear reactor. To mitigate the corrosion of structural materials, the water chemistry of the primary circuit must be carefully managed. Usually, substances such as hydrogen, ammonia, and hydrazine are employed in the reactor's primary coolant. Among these additives, ammonia and hydrazine, which are nitrogen-containing additives, undergo a series of radiolysis reactions in the reactor, and the oxidation environment of the system is altered. In this review, published studies on the radiolytic behavior of ammonia and hydrazine were summarized and analyzed. For ammonia coolants, the center dot OH radicals produced by water radiolysis react rapidly with NH3. The radiolysis product of ammonia, center dot NH2 reacted with oxidizing species such as H2O2, center dot OH, and O2. Under aerobic conditions, the radiolysis of ammonia solutions primarily led to the production of NOx-. For hydrazine coolants, NH3, H2, and N2 were formed by thermal decomposition and radiolysis. N2H4 directly inhibited the formation of H2O2 and nitrogen oxides due to its strong reducibility and ability to remove O2, center dot OH, and H2O2. As the irradiation continued, NH3 was consumed and its concentration decreased, the pH of coolant tended to decrease with further increases in absorbed dose.

This investigation examines the impact of diverse interatomic potentials on the molecular dynamics simulation results of deformation and microstructural evolution during nanomachining. The results revealed that the application of the Stillinger-Weber (SW) potential led to the occurrence of significant stacking faults and dislocations. Conversely, the Tersoff potential prevented the initiation of dislocations during the loading segment. The Tersoff potential adept representation of the high-pressure phase transformation of monocrystalline silicon throughout the nanoindentation more accurately predicted mechanical parameters when compared with experimental data. Analytical bond-order potential (ABOP) accurately delineated the deformation mechanisms, including dislocation nucleation and amorphization, during nanoscratching. In contrast, the SW potential tended to underestimate the generation of high-pressure phases, with dislocation nucleation predicted by the SW potential dominating the plastic deformation of monocrystalline Si, contradicting the experimental observations. Consequently, this study concludes that the Tersoff potential and ABOP are the preferred choices for investigating the behavior of monocrystalline Si under nanomachining conditions.

Electrocatalytic urea synthesis from CO 2 and NO 3 − offers a sustainable strategy to address environmental challenges and growing urea demand. However, current systems suffer inefficient C-N coupling due to poor selectivity toward critical C/N-intermediates. Herein, we engineered atomic-scale Mott–Schottky analogy in SnCu nanoalloy to create electron-enriched Cu sites, enabling remarkable urea production through quadruple synergy. Sn 2 Cu delivered exceptional urea yield (28.9 mmol h −1 g cat. −1 ) with 46.7% Faradaic efficiency (FE) in H-cell, while demonstrating practical potential with superior catalytic performance (yield: 72.6 mmol h −1 g cat. −1 , FE: 41.3%, stability: 60 h) at −0.52 V in flow cell. In-situ synchrotron radiation-Fourier transform infrared spectroscopy and theoretical calculations revealed electron-enriched Cu active sites enhanced CO 2 /NO 3 − co-adsorption and *CO coverage, while steering reaction pathway toward *CO-*NHO coupling and suppressing hydrogen evolution, thereby reducing rate-determining step energy barrier and prioritizing C-N coupling. This work develops a structure–adsorption-reactivity framework, providing fundamental guidance for advanced urea electrocatalyst design.

To promote the recovery and reuse of uranium resources and ensure the high efficiency development of nuclear energy, a novel ternary system composed of tributyl phosphate (TBP), kerosene and functional ionic liquid was constructed for efficient extraction of uranium under low acidity conditions. It is worth mentioning that incorporating 2.5vol% [OHEmim][NTf2] into the TBP/kerosene system substantially increases the U(VI) distribution ratio (DU) to approximately 470 times. The extraction efficiency of U(VI) (EU) reaches 99.5 %, accompanied by a DU value of 189 in the optimal conditions. Slope analysis indicates that in the TBP/kerosene/ [OHEmim][NTf2] system, the ionic liquid extracts UO22+ via a cation-exchange mechanism in the form of [UO2 & sdot;2TBP][NTf2]2. Thermodynamic studies indicate that the extraction process is driven by a highly positive entropy change. Furthermore, density functional theory (DFT) calculations elucidate the complexation mechanism between TBP and U(VI) in the presence of the ionic liquid. The results reveal that, under low acidity conditions, the complexes formed in the ionic liquid system exhibit greater stability than those in the conventional TBP/kerosene system, thereby facilitating the extraction process. Moreover, the TBP/kerosene/[OHEmim] [NTf2] system achieves a high distribution ratio for U(VI) even in the presence of multiple coexisting ions, and its extraction efficiency remained approximately 98 % after seven reuse cycles. These results demonstrate its significant practical potential for the effective recovery of U(VI). This work proves that TBP/kerosene/[OHEmim] [NTf2] system has high efficiency and reusability, which provides a crucial insight for the advancement of U(VI) recovery technology taking advantages of ionic liquids.

Removing 60Co from the primary-circuit wastewater of nuclear power plant is essential for environmental protection and the health of workers. An efficient Co2+ adsorbent was prepared by modifying amine resin D380 with carbon disulfide (CS₂) under alkaline conditions to yield xanthate-functionalized amino resin (XD380). Key experimental variables governing Co2+ uptake in aqueous media were systematically examined. The maximum adsorption capacity reached 68.07 mg g−1 at pH 7, with a XD380 dosage of 2.5 mg mL−1.The Freundlich isothermal adsorption model and pseudo-second-order adsorption kinetics effectively describe the adsorption behavior. XD380 exhibits notable radiation resistance, reusability, and adsorption selectivity. In dynamic adsorption experiments, the dynamic equilibrium adsorption capacity reached 13.17 mg g−1 under optimal conditions. Spectroscopic analyses before and after adsorption indicate that sulfur and nitrogen atomic groups serve as the primary binding sites, with Co2+ being adsorbed and fixed through chelation and complexation. These findings provide a solid experimental foundation for the potential application of XD380 in treating radioactive cobalt-bearing wastewater.

The synthesis and application of thiol-modified graphene oxide (GO-SH) for the adsorption of Co2 + from aqueous solutions constitute the primary focus of this study. Radioactive cobalt, a predominant activated corrosion product in the primary loop of nuclear power facilities, poses significant risks to both public health and environmental stability. XRD, FT-IR, XPS, BET, and SEM, were employed to characterize the microstructure of GO-SH. The characterization data demonstrate successful thiol group functionalization on the GO-SH surface and reveal an extensive porous architecture, which facilitates efficient Co2+ removal from aqueous media. The adsorption kinetics of GO-SH for Co2+ were well described by a pseudo-second-order model. Combined thermodynamic experiment and DFT calculations revealed that the adsorption process was spontaneous and exothermic. The maximum adsorption capacities of GO and GO-SH for Co2+ reached 207.97 and 598.81 mg g(-1), respectively, demonstrating significantly enhanced adsorption performance after thiol modification. This remarkable improvement in adsorption capacity can be attributed to the synergistic effects of GO-SH's hierarchical porous structure, thiol groups, amino groups, and oxygen-containing functional groups. Notably, GO-SH maintained superior adsorption performance compared to conventional adsorbents, particularly under elevated temperature conditions. Additionally, the material exhibited excellent radiation stability, making it particularly suitable for radioactive wastewater treatment applications.

With the widespread use of nuclear science and technology, slowing down the aging of polymers in a radiation environment has become a matter of great concern. In this work, cerium dioxide (CeO2) and CeO2 encapsulated with dopamine (PDA@CeO2) were selected as special fillers to prepare the silicone rubber (SR) composites, and their radiation resistance were investigated by comparing the mechanical properties and thermal performance before and after irradiation. The interfacial bridge formed by PDA results in a greater elongation at break for PDA@CeO2/SR5.0 (770.0 ± 33.6%) than for CeO2/SR (686.0 ± 15.0%). After irradiation with γ-rays, the retention of elongation at break of both CeO2/SR0.1 and PDA@CeO2/SR0.1 were larger than SR. Furthermore, PDA@CeO2/SR0.1 showed an impressive retention of 90.5 ± 2.7% of the tensile strength retention after exposure to an absorbed dose of 200 kGy. The disparity in crosslink density prior to and following irradiation indicated that both CeO2 and PDA@CeO2 were efficacious in reducing radiation crosslinking within the SR. An electron paramagnetic resonance spectrometer and an ultraviolet lamp (UV-EPR) were used to observe in real time the free radical scavenging ability of CeO2 and PDA@CeO2 inside the SR. These results indicated that CeO2 and PDA@CeO2 was expected to prevent further chain reactions in silicone rubber by scavenging free radicals generated in SR, thus improving the radiation resistance of SR.

Organophosphorus ligands such as TBP, TiAP, and DMHMP have exhibited excellent performance in recovering actinides from spent fuel. In this work, the molecular geometries and properties of TBP, TiAP and DMHMP were investigated using density functional theory calculations. Furthermore, the extraction mechanism of ligands for actinides (Np(VI), Pu(IV)) was further elucidated by simulating the microstructures and extraction reactions of metal-ligand complexes. The results demonstrate that the complexation ability of the three ligands on actinide cations (NpO22+ and Pu4+) follows the order of DMHMP > TiAP > TBP. The electrostatic potential (ESP) analysis indicates that the nucleophilic ability of DMHMP is stronger than that of the other two ligands. The frontier molecular orbital analysis of the three ligands represents that DMHMP has the highest HOMO energy, suggesting that it has the strongest electron-donating capability and is more likely to bond with metal ions. The values of Wiberg bond indices (WBI) suggest that the MO bonds in DMHMP complexes have more covalency. According to the QTAIM analysis, the interactions between actinide cations and the ligands are predominantly ionic in nature. The molecular orbital analysis of the complexes shows that the M(NO3)(n)center dot 2DMHMP (MNpO22+ and Pu4+) complexes are more stable, which is supported by thermodynamic energy analysis. This work has clarified the complexing properties of actinide cations with three ligands, shedding light on the extraction mechanisms of organophosphorus ligands for actinide cations. It is anticipated to lay the theoretical foundation for the efficient recovery of critical actinide elements in spent fuel reprocessing, which will also provide innovative approaches for the design and development of related separation processes.