Transuranium elements (TRUs) in high-level liquid waste pose long-term radiotoxic and environmental risks, and their efficient separation is essential for sustainable nuclear fuel cycles. Solid-phase adsorption has emerged as a promising method for TRU separation, offering simple operation, low secondary waste generation and tuneable selectivity under strongly acidic and radiolytic conditions. However, most existing studies are case specific, and a unified mechanistic framework to guide material design is lacking. In this review, we propose a mechanism-oriented framework that categorizes solid-phase TRU separation into four synergistic mechanisms: (1) coordination–electrostatic interaction, (2) ion exchange–electrostatic interaction, (3) chemical-state conversion–selective partitioning, and (4) molecular recognition–phase transition. Within this framework, we survey recent advances in metal–organic frameworks, covalent organic frameworks, inorganic frameworks and functionalised polymers. We identify common design principles that link donor groups, framework topology, charge distribution and redox-active sites to separation performance under highly acidic, nitrate-rich and radiolytic conditions. This review highlights key challenges and future directions, including multi-mode cooperative designs and material property enhancement. This mechanism-oriented framework is expected to advance TRU separation beyond empirical screening and accelerate the rational design of robust solid-phase materials and processes, facilitating advanced nuclear fuel cycles and sustainable nuclear energy development.

Highly efficient and accurate analysis of ultra-trace anthropogenic 236U in the presence of natural uranium isotopes is essential for nuclear forensics and environmental monitoring. In this study, we developed an integrated analytical method for the determination of 234U, 235U, 236U, and 238U by combining highly automated sample preparation with highly sensitive ICP-MS/MS detection. Automated total dissolution was employed to ensure complete extraction of both endogenous and exogenous uranium from solid matrices, while reproducible chemical separation was achieved using an automated platform equipped with regenerable UTEVA resin. This optimized procedure yielded exceptionally low operational blanks for 236U at femtogram level. Moreover, the final eluent volume was minimized to 1.5 mL, allowing direct introduction into the ICP-MS/MS. By utilizing a membrane desolvation sample introduction system and a novel mass-shift mode (targeting UO2+ species), the ICP-MS/MS sensitivity exceeded 4.1 × 106 cps/ppb, while the 235UH + interference formation rate for 236U was suppressed to 7.1 × 10-10. Consequently, the achieved detection limits for 236U and the 236U/238U atom ratio were as low as 1.85 fg/g and 5 × 10-12, respectively. This method was successfully applied to determine the uranium isotopic composition in sediments from the adjacent sea area of the Daya Bay Nuclear Power Plant. These results demonstrate that the proposed method provides a robust and high-throughput solution for accurately quantifying of ultra-trace 236U in environmental samples, such as those impacted by the global fallout.

Accurately identifying plutonium (Pu) valence states is critical to the safety and efficiency of nuclear fuel reprocessing. In this study, an analytical method for Pu valence state speciation was developed based on capillary electrophoresis hyphenated to inductively coupled plasma mass spectrometry (CE-ICP-MS), enabling effective separation and quantification of Pu(III), Pu(IV), and Pu(VI). Optimal separation conditions were established using surrogate elements with stable oxidation states and 2-hydroxyisobutyric acid (alpha-HIBA) as the background electrolyte (BGE). Under optimized conditions, the migration order of Pu valence states was determined as Pu(III) > Pu(VI) > Pu(IV), with a relative standard deviation (RSD) of migration time < 1.5%, indicating excellent analytical repeatability. The method was successfully applied to monitor the reduction of Pu(VI) by zero-valent iron (Fe-0), elucidating the valence state transformation kinetics (Pu(VI) -> unstable Pu(IV) intermediate -> Pu(III)). Notably, the method exhibited robust anti-interference capability in high uranium (U) matrices, maintaining baseline separation of Pu valence states even at a U/Pu ratio of 100. This study provides a novel, reliable approach for Pu speciation analysis in complex nuclear matrices, with significant implications for process control and Pu recovery in nuclear fuel reprocessing.

The separation of xenon from krypton holds significant importance across various fields, including high-tech industries, national defence, and aerospace. Adsorptive separation via porous solids is considered one of the most promising alternatives to conventional energy-intensive cryogenic processes. While traditional adsorbents selectively capture xenon over krypton under ambient conditions, their desorption energy penalties for producing pure xenon impede practical implementation. Here, we present a metal‒organic framework characterized by synergistic structural and local flexibility that reverses conventional selectivity, thereby enabling preferential adsorption of krypton at room temperature. This material demonstrates a krypton uptake of 36.8 cm3 cm-3 (298 K, 1 bar) and achieves a Kr/Xe selectivity of 10.4 in 1/99 Kr/Xe mixture breakthrough experiments. Moreover, this material exhibits commendable radioactive stability and effectively captures trace amounts of krypton (40 ppm). Mechanistic studies indicate that dynamic adjustments in cavity windows and localized ligand vibrations work synergistically to exploit subtle size differences between krypton and xenon. This enables kinetically controlled sieving of krypton through transiently expanded channels. With an energy-efficient approach to krypton-centric separation, our research redefines the design paradigm for noble gas purification and offer new possibilities for separating other dynamically matched molecules through adaptive host‒guest interactions. Efficient Kr/Xe separation is crucial for high-tech industries, defense, and aerospace applications. While conventional adsorbents typically capture Xe, their application is hindered by high energy costs during desorption. Here authors present a MOF with synergistic structural dynamics and local flexibility that reverses conventional selectivity, enabling preferential adsorption of Kr at room temperature.

99Tc is present in the radioactive wastewater generated from spent fuel reprocessing and poses a serious threat to the environment. Due to the strong radioactivity, high ionic strength, and high acidity of nuclear wastewater, selectively extracting 99Tc remains a significant challenge. This study developed a novel electrochemically switched ion exchange technology and a SnS nanoflower/graphene oxide (SSF/GO) composite electrode for selectively extracting ReO4-/TcO4-. The electrode exhibited a high adsorption capacity of 1812 mg g-1 for Re, and it maintained excellent extraction efficiency even in a high-concentration nitric acid system (3 mol L-1) similar to nuclear wastewater. The SSF/GO electrode also exhibits excellent selectivity and cycling stability. Furthermore, the study revealed that the exceptional performance of the SSF/GO electrode originates from the synergistic effects of electrochemical reduction, chemical reduction, and ion exchange. In conclusion, this research provides valuable insights into the development of efficient synergistic systems integrating electrochemical reduction, chemical reduction, and ion exchange to enhance ion capture efficiency. It holds promising potential for nuclear wastewater treatment by significantly improving ion capture efficiency.

Despite the burgeoning interest in high‐entropy materials (HEMs), their application as scintillators remains largely untapped. Herein, we report the first design of high‐entropy lanthanide‐based metal‐organic frameworks (HE‐Ln‐MOFs) incorporating five distinct lanthanides (La, Ce, Eu, Dy, and Er) as multifunctional porous scintillators. These materials exhibit stimulus‐responsive luminescence, enabling switchable white‐light emission and self‐calibrating thermometry. The HE‐Ln‐MOFs demonstrate a balanced optimization of key scintillation parameters, achieving a light yield of ∼17000 photons per MeV and a detection limit as low as 302 nGy air s −1 . X‐ray adsorption spectroscopy (XAS) and theoretical calculations reveal a unique multistep energy transfer (ET) pathway mediated by the Ce 3+ /Ce 4+ redox pair, presumably generated under high‐energy X‐ray irradiation. Furthermore, HE‐Ln‐MOFs demonstrate exceptional structural integrity, photostability, and a record uranyl adsorption capacity of 1532 mg g −1 , advantageous over their monometallic analogues. The synergy between ultrahigh adsorption, “turn‐on” photoluminescence (PL), and intense scintillating signal output portends unprecedented dual‐mode, on‐site detection of radionuclides in aqueous environments. This work establishes HE‐Ln‐MOFs as a promising platform for next‐generation porous scintillators in advanced radiation detection technologies.

The integration of separation and detection of uranyl ions under acidic conditions remains a major challenge. Lanthanide metal phosphonate frameworks exhibit unique selectivity, stability, and luminescent properties, holding extraordinary potential in the field of separation and detection of actinides. A novel series of porous lanthanide phosphonate framework materials had been synthesized, namely QSZ-Ln (Ln = La, Ce, Pr, Nd), demonstrating their superior uranium extraction capability in acidic media (pH 1). Among them, QSZ-Nd exhibits a high uranyl adsorption capacity of 928 mg/g at pH 1 and demonstrates excellent selectivity, with a distribution coefficient of 1.96 x 106 mL/g. Characterization experiments and mechanistic studies have revealed that a metal substitution reaction occurs during the adsorption process of QSZ-Nd and UO22+ in acidic aqueous solution. Meanwhile, based on the energy transfer effect of UO22+-> Nd3+, QSZ-Nd can establish a fluorescence sensing function, achieving in-situ response to trace amounts of uranium in acidic environments. This material successfully integrates actinium separation and detection functions, providing a new technological route for uranium resource recovery and monitoring in complex systems.

Bismuth telluride (Bi2Te3)-based alloys have been extensively employed in energy harvesting and refrigeration applications for decades. However, commercially produced Bi2Te3-based alloys using the zone-melting (ZM) technique often encounter challenges such as insufficient mechanical properties and susceptibility to cracking, particularly in n-type Bi2Te3-based alloys, which severely limit the application scenarios for bismuth telluride devices. In this work, we seek to enhance the mechanical properties of n-type Bi2Te2.7Se0.3 alloys while preserving their thermoelectrical performance by a mixed mechanism of grain refinement and the TiN composite phase-introduced pinning effect. These nanoscale processes, coupled with the addition of TiN, result in a reduction in grain size. The pinning effects of nano-TiN contribute to increased resistance to crack propagation. Finally, the TiN-dispersed Bi2Te2.7Se0.3 samples demonstrate increased hardness, bending strength and compressive strength, reaching 0.98 GPa, 36.3 MPa and 74 MPa. When compared to the ZM ingots, those represent increments of 181%, 60% and 67%, respectively. Moreover, the thermoelectric performance of the TiN-dispersed Bi2Te2.7Se0.3 samples is identical to the ZM ingots. The samples exhibit a peak dimensionless figure of merit (ZT) value of 0.957 at 375 K, with an average ZT value of 0.89 within the 325-450 K temperature range. This work has significantly enhanced mechanical properties, increasing the adaptability and reliability of bismuth telluride devices for various applications, and the multi-effect modulation of mechanical properties demonstrated in this study can be applied to other thermoelectric material systems.

The design and fabrication of uranium phosphonate frameworks (UPFs) pave a potential avenue to reduce the environmental risk of depleted uranium, transuranium waste, and toxic gases while adding to its waste to utility virtues. However, it remains unknown how the pervasive coordinated water of UPFs influences their performances in radionuclide and toxic gas separation. Toward this end, we prepared a new category of porous UPFs, namely UPF-205 with abundant coordinated water and resulting hydrogen bonding nanotraps. The coordinated water is synergistic in quantitatively removing trivalent f-elements (i.e., Am3+, Eu3+) from wide-ranging pH solutions together with proximal phosphonate groups at a low metal concentration. Most importantly, an unprecedented coordinated water-mediated Eu3+-UO22+ transmetalation had been verified at a relatively high metal concentration. The high-density open uranyl sites and optimal pore size triggered by the dehydration of coordinated water also contribute to the enhanced adsorption of toxic SO2 and NH3. Our work shows great relevance for the rational design of ultrastable UPFs as both depleted uranium waste forms and efficient adsorbents for radiological/nuclear protection.

Tetravalent metal (e.g., Zr4+, Hf4+) phosphonate frameworks featuring remarkable chemical and radiolytic stabilities have been newly utilized as high-performing adsorbents for actinide in harsh solutions. Nevertheless, the practical applications have been impeded by the as-synthesized powder form that is not compatible with continuous actinide recovery or removal. Herein, we incorporate hafnium phosphonate (HfP) fine powder into polyacrylonitrile (PAN) via a simple and economical electrospinning technique, engendering a stable and hy-drophilic nanofibrous membrane with the first-rank permeate flux for the potential treatment of a large volume of actinide-containing wastewater. This composite membrane can capture more than 90% Th(IV) at ppm level and 95% Pu(IV) and 90% Np(V) at tracer amount level in strong acidic solutions, which retains the excellent adsorption efficacy of HfP powder. Besides, it has a breakthrough volume larger than 880 mL for Th(IV) and 760 mL for U(VI) at the ppb level under a high permeate flux of 785 +/- 11.2 L center dot m-2 center dot h-1, representing one of the top nanofibrous membranes for the dynamic removal of actinides. This work will pave an avenue for fabricating highly efficient and stable adsorptive membranes, which are promising candidates for capturing actinides from large-volume of acidic nuclear wastewater.

The synthesized SSF nanoflowers have high adsorption capacity and excellent selective separation ability for ReO4− in 3 M HCl solution.

Methods for Pu determination in water samples has been longtime studied but they generally involved tedious manual operations. In this context, we proposed a novel strategy for accurate determination of ultra-trace Pu in water samples by the combination of fully automated separation with direct ICP-MS/MS measurement. A recently commercialized extraction resin TK200 was used for single-column separation due to its distinctive nature. Acidified waters up to 1 L were directly loaded to the resin at high flow rate (15 mL min -1) with omitting the frequently used co-precipitation process. Small volumes of dilute HNO3 were used for column washing, and Pu was efficiently eluted within only 2 mL 0.5 mol L-1 HCl-0.1 mol L-1 HF with a stable recovery (65%). This separation procedure was fully automated under the control of user program, meanwhile the final eluent was compatible for direct ICP-MS/MS measurement without extra sample treatment. In that way, both the labor intensity and reagent consumption were minimized compared with existing methods. With the high decon-tamination (104 to 105) of U in the chemical separation and the further elimination of uranium hydrides under oxygen reaction model during ICP-MS/MS measurement, the overall interference yields of UH+/U+ and UH2+/U+ were down to 10-15. The limits of detection (LODs) of this method reached 0.32 mu Bq L-1 for 239Pu and 2.00 mu Bq L-1 for 240Pu, which were much lower than those stipulated in the general guidelines for drinking water stan-dards, suggesting this method was promising in routine or emergency radiation monitoring. Furthermore, the established method was successfully applied in a pilot study to determine global fallout derived Pu in surface glacier samples with extremely low concentrations of 239+240Pu, which suggested the method would also be feasible in glacial chronology studies in the future.

With the advocation of green analytical chemistry (GAC), the development of eco- and operator friendly analytical practices is highly concerned. This could be more noteworthy for the radioanalytical chemistry as hazardous radioactivity present during the analytical procedures. For the first time, herein we critically reviewed the practices and progresses of radioanalytical methodologies for typical nuclides from the perspective of GAC. Different stages of the general radioanalytical procedures were considered. On this basis, practices and progresses of the methodologies were dialectically discussed from two aspects, viz., the analytical performances and the analytical greenness. In the end, future trends of radioanalytical methodologies for different nuclides were proposed. Although in many cases the implementation of GAC might deteriorate the analytical performances, with the aid of multi-nuclide separation procedure as well as automatic techniques, it is promising to improve the analytical greenness meanwhile satisfy the analytical requirements for specific application purposes.

The analysis of 241Am in environmental samples is of great importance in the fields of geological repositories and radiation protection. The triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) has a strong analytical and interference removal capability for long half-life radionuclides. In this study, the ability of ICP-MS/MS to determine ultra-trace level of 241Am in environmental samples was further explored. The instrumental sensitivity for Am detection was significantly improved (ca. 20 times) by employing an APEX-omega high efficiency introduction system. The gases of O2 and He were introduced to the reaction cell for eliminating of interferences and Am was detected as AmO+ ions. High separation factors (>2000) of Am and Pu were ob-tained at proper gas flow rates by chemical resolution of the instrument. Meanwhile, the background signals caused by possible polyatomic interferences for 241Am and 243Am were sufficiently reduced. A simple and rapid chromatographic separation method for purposeful and efficient separation of 241Am from matrix and interfering elements was developed. The overall chemical recoveries were about 68% and the detection limit of 241Am for the established method was 0.18 fg g-1 (equivalent to 0.02 mBq g-1). Several marine sediment reference ma-terials were analyzed for the validation of the method and the results showed that this method was suitable for the determination of 241Am in solid environmental samples. The method was finally applied to real marine sediment samples collected in the western North Pacific after the Fukushima nuclear accident.

The effect of irradiation on actinide sorbents potentially employed in nuclear waste management, should be investigated to evaluate their feasibility in real-world applications. In this study, hafnium-amino trismethylene phosphonate (Hf-ATMP), which is a type of organic-inorganic hybrid sorbents for actinides, was exposed to Co-60 gamma rays, and the effects of ionising radiation on actinide sorption performance and its microstructure were investigated. Thereafter, the irradiation effect on other materials of this type was studied. The results revealed that the actinide sorption performance of Hf-ATMP was significantly enhanced by irradiation; the saturated Th (IV) sorption capacity of Hf-ATMP increased by 58.1% after irradiation with a dose of 2.4 MGy. The selectivity for actinides and the sorption performance for trace amounts of radioactive Pu-239 and Np-237 were also comparable to those of pristine Hf-ATMP. The structural characterisation of Hf-ATMP before and after irradiation indicated that the P-O-H groups in Hf-ATMP were converted into P-O-Hf groups upon irradiation. The pore volume and BET surface area of Hf-ATMP decreased, but the bulk chemical structure of Hf-ATMP was not damaged by gamma irradiation. Additionally, the enhancement of actinide sorption performance by gamma irradiation was observed with several other metal phosphonates. The results indicated the application potential of metal phosphonates as actinide sorbents in practical nuclear processes. Besides, this study opens a new door for improving the sorption performance of metal phosphonate sorbents using irradiation techniques.

A relatively new branch of science - nuclear forensics, aiming at providing the nature, origin, history and possible trafficking route of seized nuclear materials/devices, has been established and rapidly developed over decades to screen illicit nuclear activities. This highly interdisciplinary science is built upon a foundation of analytical chemistry, radiochemistry, nuclear physics, material sciences, geology, and other scientific disciplines, within which radiochemical methodologies and radioanalytical techniques play a key role. The present review provides a brief overview about the crucial aspects of nuclear forensics, including basic content, procedure, concerned elements, common separation, analytical method, and so on. The state of the art and recent progresses of nuclear forensics by research communities in China are reviewed, while selected examples and practical applications are emphasized. The challenges associated with this new area and on-going developments are highlighted and discussed.

The selective sorption of plutonium from radioactive wastes is of high economic and strategic importance. Herein, the self-assembled Ag32Cd12(SPh4-OMe)(36) (SPh4-OMe = 4-methoxyphenylthiolate) have been developed as a powerful plutonium separating material. Compared to its non-assembled analogue of the trimetallic Au4Ag28Cd12(SPh4-OMe)(36) cluster, the bimetallic AgCd alloy cluster shows excellent binding affinity and selectivity to 239Pu(IV) over the other radionuclides (such as( 237)Np(V), Am-241(III), etc). The maximum value of the distribution coefficient (Kd) and separation factors reaches 3 x 10(4) mL g(-1) and 7.52 x 10(3) at pH = 3. The significantly higher selectivity of the AgCd clusters than that of the reported solid-phase materials might originate from the regular, inter-cluster assembly via formation of the cyclic ...Ag-S...Ag-S... interactions in the exterior AgS3 motifs.

High-efficiency analysis of Th and U isotopes are important technical issues encountered in the fields such as environment monitoring and nuclear emergency responses.

U, Sr, Pb, Nd, and Hf isotope ratios can provide basic and important information of nuclear materials. We established a simple and efficient column chemistry method using nano-NaBiO3, as both oxidizer and adsorbent, to completely separate Ce from rare earth elements (REEs). This new method exhibited a high decontamination (Ce/Nd < 10(-5)) ability and was easy to conducted, thereby providing clear advantages compared to traditional liquid-liquid and solid phase micro-extraction techniques. Additionally, a rapid four-column separation procedure, based on Sr, TUR, Ln resins and nano-NaBiO3, was developed to isolate U, Sr, Pb, Nd, and Hf in ore samples. The entire procedure could be completed in 4-5 hrs. The robustness of the proposed method was demonstrated by analyzing the U-235/U-238, Sr-87/Sr-86, Pb-206/Pb-204, Pb-207/Pb-204, Pb-208/Pb-204, Nd-142/Nd-144, Nd-143/Nd-144, and Hf-176/Hf-177 isotopic ratios of two certified reference materials (CRMs). The analytical results obtained using this method showed good agreement with previously published data. The feasibility of this method was extended to the determination of isotope ratios in uranium ores. The results obtained from the two samples with different regions indicated that they have different isotopic ratios information. These findings indicate the potential for the use of this new method in nuclear forensic science.

A major environmental concern related to nuclear energy is wastewater contaminated with uranium, thus necessitating the development of pollutant-reducing materials with efficiency and effectiveness. Herein, highly selective mesoporous silicas functionalized with amine-bridged diacetamide ligands SBA-15-ABDMA were prepared. Different spectroscopy techniques were used to probe the chemical environment and reactivity of the chelating ligands before and after sorption. The results showed that the functionalized SBA-15-ABDMA had a strong affinity for uranium at low pH (pH = 3) with desirable sorption capacity (68.82 mg/g) and good reusability (> 5). It showed excellent separation performance with a high distribution coefficient (Kd,U > 105 mL/g) and separation factors SFU/Ln > 1000 at a pH of 3.5 in the presence of lanthanide nuclides, alkaline earth metal and transition metal ions. In particular, SiO2spheres-ABDMA was used as a column material, which achieved excellent recovery of U(VI) (> 98%) and good reusability for samples of simulated mining and nuclear industries wastewater. XPS and crystallography studies clearly illustrated the tridentate coordination mode of U(VI)/PEABDMA and the mechanism and origin behind the high selectivity for U.