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Two‐electron oxidative addition is one of the most important elementary reactions for d‐block transition metals but it is uncommon for f‐block elements. Here, we report the first examples of intermolecular oxidative addition of E−H (E=C, N) bonds to uranium(II) centers. The transient U(II) species was formed in‐situ by reducing a heterometallic cluster featuring U(IV)‐Pd(0) bonds with potassium‐graphite (KC8). Oxidative addition of C−H or N−H bonds to the U(II) centers was observed when this transient U(II) species was treated with benzene, carbazole or 1‐adamantylamine, respectively. The U(II) centers could also react with tetracene, biphenylene or N2O, leading to the formation of arene reduced U(IV) products and uranyl(VI) species via two‐ or four‐electron processes. This study demonstrates that the intermolecular two‐electron oxidative addition reactions are viable for actinide elements. [ABSTRACT FROM AUTHOR]

Large volumes of water containing tritium are generated during the operation, decommissioning, and incident-management of nuclear installations and related facilities, and are expected to increase with the ongoing expansion of nuclear power generation. If released into the environment, this water could pose a substantial environmental threat to living organisms. However, conventional isotope separation techniques, such as cryogenic distillation and catalytic exchange, are inadequate for efficiently isolating significant quantities of low-level tritiated water because of the complex machinery and excessive energy required, and the potential for hydrogen-gas detonation. In contrast, water distillation (WD), as a traditional technology, has the unique advantages of simple operation, no corrosive and toxic substances, and no hydrogen explosion risk, but problems of small separation coefficient and low efficiency always exist in this technique. However, the separation effect of WD can be effectively improved by improving the process variables in the process of WD, such as temperature, distillation column diameter, and packing dimensions, so as to adapt WD to the separation of industrial tritiated water. This study provides a thorough exposition of the basic principles and distinctive features of water distillation and examines the effect of various operational parameters on separation efficiency to adapt the process for the industrial separation of tritiated water. The impact of various process variables on the separation efficiency of tritiated water via distillation was investigated, and results show that optimizing these variables can markedly improve the separation efficiency of water distillation. In particular, decreasing the dimensions of the packing material or altering its properties can lead to higher separation factors and lower residual tritiated water concentration. These findings suggest that water distillation can be used for the separation of tritiated water. By optimizing its operational parameters, water distillation can become a viable method for the industrial separation of tritiated water and is expected to play a significant role in this field in the future.

Harnessing solar energy by photocatalytically converting oxygen and water into high-value-added H2O2 is a promising way of alleviating both environmental and energy issues. It is worth noting that suppressing detrimental side reactions, such as the generation of •O2−, is a critical approach to enhancing H2O2 production. Herein, a 2-fold interpenetrating 3D uranium-organic framework (YTU-W-1) was developed and introduced for photocatalytic H2O2 production. The material demonstrates a different photocatalytic mechanism when employing uranyl as an initiator, as compared with the conventional semiconductor photocatalytic pathway involving photo-generated charge carriers. Benefiting from the strong hydrogen abstraction effect of the U≡O• and the direct one-step oxygen reduction pathway, YTU-W-1 exhibits enhanced photocatalytic performance for H2O2 production with yield efficiency of 221 µmol h−1 g−1. Furthermore, YTU-W-1 displays a high H2O2 selectivity of 68%, confirmed by rotating ring-disk electrode (RRDE) measurement. DFT calculations were used to elucidate the critical role of uranyl in the photocatalytic oxygen reduction reaction for H2O2 production. This research introduces an innovative approach to photo driven H2O2 production, underscoring the potential for heterogeneous catalysts to engage in photocatalytic reactions independently of photo-generated charge carriers. [ABSTRACT FROM AUTHOR]

Metal‐organic framework (MOF) based heterostructures, which exhibit enhanced or unexpected functionality and properties due to synergistic effects, are typically synthesized using post‐synthetic strategies. However, several reported post‐synthetic strategies remain unsatisfactory, considering issues such as damage to the crystallinity of MOFs, presence of impure phases, and high time and energy consumption. In this work, we demonstrate for the first time a novel route for constructing MOF based heterostructures using radiation‐induced post‐synthesis, highlighting the merits of convenience, ambient conditions, large‐scale production, and notable time and energy saving. Specifically, a new HKUST‐1@Cu2O heterostructure was successfully synthesized by simply irradiating a methanol solution dispersed of HKUST‐1 with gamma ray under ambient conditions. The copper source of Cu2O was directly derived from in situ radiation etching and reduction of the parent HKUST‐1, without the use of any additional copper reagents. Significantly, the resulting HKUST‐1@Cu2O heterostructure exhibits remarkable catalytic performance, with a catalytic rate constant nearly two orders of magnitude higher than that of the parent HKUST‐1. [ABSTRACT FROM AUTHOR]

As a critical radioactive anionic contaminant, traditional adsorbents primarily remove iodate (IO3−) through ion exchange or hard acid‐hard base interactions, but suffer from limited affinity and capacity. Herein, employing the synergistic effect of ion exchange and redox, we successfully synthesized a redox‐active cationic polymer network (SCU‐CPN‐6, [C9H10O2N5 ⋅ Cl]n) by merging guanidino groups with ion‐exchange capability and phenolic groups with redox ability via a Schiff base reaction. SCU‐CPN‐6 exhibits a groundbreaking adsorption capacity of 896 mg/g for IO3−. The inferior adsorption capacities of polymeric networks containing only redox (~0 mg/g) or ion exchange (232 mg/g) fragments underscore the synergistic "1+1>2" effect of the two mechanisms. Besides, SCU‐CPN‐6 shows excellent uptake selectivity for IO3− in the presence of high concentrations of SO42−, Cl−, and NO3−. Meanwhile, a high distribution coefficient indicates its exemplary deep‐removal performance for low IO3− concentration. The synergic strategy not only presents a breakthrough solution for the efficient removal of IO3− but also establishes a promising avenue for the design of advanced adsorbents for diverse applications. [ABSTRACT FROM AUTHOR]

In conjunction with theoretical calculations, the in vitro and in vivo uranyl binding capabilities of a bidentate picolinate (Pic) ligand and its pentadentate derivative (H2dpa) are investigated. The planar N3O2-donor configuration of H2dpa matches the typical pentagonal-bipyramid coordination geometry of uranyl, demonstrating a remarkable removal preference for uranyl in the kidneys. [ABSTRACT FROM AUTHOR]

The development of adsorbent materials for effective capture of radioactive iodomethane (CH3I) from the off-gas of used nuclear fuel reprocessing, remains a significant and challenging line of research because currently state-of-art adsorbents still suffer from low binding affinity with CH3I. Here, we proposed a brand-new adsorption topological structure by developing a 2D interdigitated layered framework, named SCU-20, featuring slide-like channel with multiple active sites for CH3I capture. The responsive rotating-adaptive aperture of SCU-20 enables the optimal utilization of all active sites within the pore for highly selective recognition and capture of CH3I. A record-breaking CH3I uptake capacity of 1.84 g/g was achieved under static sorption conditions with saturated CH3I vapor. Both experimental and theoretical findings demonstrated that the exceptional uptake of SCU-20 towards CH3I can be attributed to the confined physical electrostatic adsorption of F sites, coupled with the chemical nitrogen methylation reaction with uncoordinated N atoms of pyrazine. Moreover, dynamic CH3I uptake capacity potentially allows for the capture of CH3I in simulated real-world off gas reprocessing conditions. This study highlights the potential of SCU-20 as a promising candidate for efficient capture of iodine species and contributes to the development of effective solutions for radioactive iodine remediation. [ABSTRACT FROM AUTHOR]

Efficient adsorption of palladium ions from acid nuclear waste solution is crucial for ensuring the safety of vitrification process for radioactive waste. However, the limited stability and selectivity of most current adsorbents hinder their practical applications under strong acid and intense radiation conditions. Herein, to address these limitations, we designed and synthesized an aryl‐ether‐linked covalent organic framework (COF‐316‐DM) grafted dimethylthiocarbamoyl groups on the pore walls. This unique structure endows COF‐316‐DM with high stability and exceptional palladium capture capacity. The robust polyarylether linkage enables COF‐316‐DM to withstand irradiation doses of 200 or 400 kGy of β/γ ray. Furthermore, COF‐316‐DM demonstrates fast adsorption kinetics, high adsorption capacity (147 mg g−1), and excellent reusability in 4 M nitric acid. Moreover, COF‐316‐DM exhibits remarkable selectivity for palladium ions in the presence of 17 interference ions, simulating high level liquid waste scenario. The superior adsorption performance can be attributed to the strong binding affinity between the thioamide groups and Pd2+ ions, as confirmed by the comprehensive analysis of FT‐IR and XPS spectra. Our findings highlight the potential of COFs with robust linkers and tailored functional groups for efficient and selective capture of metal ions, even in harsh environmental conditions. [ABSTRACT FROM AUTHOR]

Halide perovskites (HPs) recently have emerged as one class of competitive scintillators for X‐ray detection and imaging owing to its high quantum efficiency, short decay time, superior X‐ray absorption capacity, low cost, and ease of crystal growth. The tunable structure and versatile chemical compositions of halide perovskites provide distinguishable advantages over traditional inorganic scintillators for optimizing scintillation performance. Since the first observation of the scintillation phenomenon in HPs, substantial efforts have been devoted to expanding the inventory of HP scintillators and regulating material properties. Understanding the relationship between the structure and scintillation properties of HP scintillators is essential for developing materials with improved X‐ray detection and imaging capacities. This review summarizes strategies for improving the light yield of HP scintillators and provides a roadmap for improving the X‐ray imaging performance. Additionally, methods for controlling the light propagation direction in HP scintillators are highlighted for improving X‐ray imaging resolution. Finally, we highlight the current challenge in HP scintillators and provide a perspective on the future development of this emerging scintillator. [ABSTRACT FROM AUTHOR]

The development of high‐performance X‐ray detectors requires scintillators with fast decay time, high light yield, stability, and X‐ray absorption capacity, which are difficult to achieve in a single material. Here, we present the first example of a lanthanide chalcogenide of LaCsSiS4 : 1 % Ce3+ that simultaneously integrates multiple desirable properties for an ideal scintillator. LaCsSiS4 : 1 % Ce3+ demonstrates a remarkably low detection limit of 43.13 nGyair s−1 and a high photoluminescence quantum yield of 98.24 %, resulting in a high light yield of 50480±1441 photons/MeV. Notably, LaCsSiS4 : 1 % Ce3+ exhibits a fast decay time of only 29.35±0.16 ns, making it one of the fastest scintillators among all lanthanide‐based inorganic scintillators. Furthermore, this material shows robust radiation and moisture resistance, endowing it with suitability for chemical processing under solution conditions. To demonstrate the X‐ray imaging capacity of LaCsSiS4 : 1 % Ce3+, we fabricated a flexible X‐ray detector that achieved a high spatial resolution of 8.2 lp mm−1. This work highlights the potential of lanthanide chalcogenide as a promising candidate for high‐performance scintillators. [ABSTRACT FROM AUTHOR]

Periodically arranging coordination‐distinct actinides into one crystalline architecture is intriguing but of great synthetic challenge. We report a rare example of a heterobimetallic actinide metal–organic framework (An‐MOF) by a unique reaction‐induced preorganization strategy. A thorium MOF (SCU‐16) with the largest unit cell among all Th‐MOFs was prepared as the precursor, then the uranyl was precisely embedded into the MOF precursor under oxidation condition. Single crystal of the resulting thorium‐uranium MOF (SCU‐16‐U) shows that a uranyl‐specific site was in situ induced by the formate‐to‐carbonate oxidation reaction. The heterobimetallic SCU‐16‐U exhibits multifunction catalysis properties derived from two distinct actinides. The strategy proposed here offers a new avenue to create mixed‐actinide functional material with unique architecture and versatile functionality. [ABSTRACT FROM AUTHOR]