Science China Chemistry最新文献

The removal of trace plutonium (Pu) from uranium products and organic wastes during spent nuclear fuel reprocessing remains a critical challenge, resulting in excessive plutonium content in uranium products and waste organic liquid. Currently, most organic ligands with selective separation functions are lipophilic, while research on water-soluble, highly selective ligands is relatively scarce, and there are also few reports on the single crystal of these ligands coordinating with plutonium. Herein, a hydrophilic multiamide ligand, N,N,N′,N″,N″-hexaethyl-nitrilotriacetamide (NTAamideC2), was synthesized and evaluated for its Pu(IV) back-extraction efficiency under harsh conditions. Systematic experiments revealed that NTAamideC2 achieved >99% Pu(IV) back-extraction rate within 15 min across a wide nitric acid concentration range (0–5 M), even with elevated dibutyl phosphate (DBP ⩽20000 ppm). Remarkably, the separation factor (SFPu/U) reached 767 at 1.5 M HNO₃, demonstrating exceptional selectivity over uranium(VI). Spectrophotometric titration and DFT calculations confirmed the formation of 1:1 and 1:2 Pu(IV)-NTAamideC2 complexes, with logβ values of 7.42 ± 0.01 and 13.23 ± 0.02, respectively. Single-crystal X-ray diffraction analysis of {[Pu₂(H₂O)₂(NTAamideC2)₄](H₂O)₂(NO₃)(ClO₄)₇} revealed a nine-coordinated PuO₇N₂ geometry, where two NTAamideC2 molecules bind via six O and two N atoms. Compared to conventional agents (AHA/HSC), NTAamideC2 exhibited superior acid tolerance and selectivity, aligning with the CHON principle for sustainable nuclear waste management. This work provides a robust strategy for Pu(IV) removal in uranium purification cycles and advances fundamental insights into Pu coordination chemistry, offering significant potential for industrial nuclear fuel reprocessing.

Semi-transparent organic photovoltaics (ST-OPVs) have great potential for photovoltaic building integration and agricultural greenhouse energy. However, the mutually constraining relationship between average visible transmittance (AVT) and power conversion efficiency (PCE) remains a key issue of ST-OPVs. Herein, we innovatively applied a surface texturization strategy by integrating with a pseudo-planar heterojunction (PPHJ) structure to fabricate ST-OPVs, which possess outstanding photoelectric conversion and light management capability. The textured active layer performs significantly improved light capture capability and reduced optical loss due to that the micro-patterned arrays can deflect incident light multiple times. Moreover, the surface texturization strategy can enhance the crystallinity of the active layer and precisely control donor/acceptor inter-penetration, which magnifies exciton dissociation interface and forms ordered carrier dynamics. Consequently, the textured opaque device via blade-coating performs a record PCE of 19.17% (certified 19.02%) and the semi-transparent device achieves one of the highest light utilization efficiency (LUE) of 5.54% with prominent PCE (14.40%) and AVT (38.43%). Most importantly, the excellent thermal insulation performance and color rendering index of ST-OPVs are fitting for the agricultural greenhouses and insulation roofing, which shows that the surface texturization strategy can provide promising application prospects for ST-OPVs in economically sustainable agricultural development.

Li-rich layered oxide (LLO) cathode materials have been known as possible cathode materials for application in the high energy density lithium batteries based on their high specific capacity, high energy density, and relatively low cost. However, there are several problems that limit its commercial applications on a large scale. The main problems include low initial Coulombic efficiency, poor rate performance, significant capacity fading, and voltage decay during charge-discharge cycles. Using solid-state electrolytes (SSEs) to replace current widely used liquid electrolytes (LEs) has been considered as a promising method to improve the electrical performance of the LLO-based lithium batteries and it is worth studying in depth. In this review, we summarize the investigations of SSEs applied in the LLO cathodes and discuss how to improve the performance of LLO-based lithium batteries through SSEs. At the beginning, the current issues of LLO cathode limiting its application have been generalized. Then, the possible strategies to improve LLO cathodes by SSEs are discussed in detail. SSEs can be roughly divided into quasi-solid-state electrolytes (QSSEs) and all-solid-state electrolytes (ASSEs). QSSEs include the electrolytes prepared by in-situ polymerization and swelling effect, while ASSEs contain oxide-based, sulfide-based and halogen-based SSEs. Finally, the review lists challenges for the SSEs applied in LLO cathodes for both QSSEs and ASSEs and provides some potential suggestions for SSEs to overcome the shortcomings when they are applied in the LLO cathodes. The key point is to increase the stability with LLO cathodes at 4.8 V and the compatibility with Li based anode. This review would promote future commercial applications of LLO cathode-based high energy density and high safety lithium batteries.

The rationally designed ruthenium selenide (RuSe_1.6-500) nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach. During the annealing step, calcination under a H₂/Ar atmosphere facilitated the evaporation of selenium, thereby generating selenium vacancies. This study confirmed that RuSe_1.6-500 prepared by this method functions as an efficient electrocatalyst for the hydrogen evolution reaction (HER) in seawater. Furthermore, experiments and density functional theory calculations demonstrated that the enhanced electrocatalytic performance and resistance to Cl-induced corrosion in seawater can be attributed to the surface reconstruction of RuSe_1.6-500 during the HER process. Specifically, the reconstruction involves the adsorption of hydroxyl groups at selenium vacancies, leading to the formation of a hydroxy-rich surface on RuSe_1.6-500. The hydroxy-rich surface is responsible for the superior electrocatalytic activity and stability of RuSe_1.6-500 as an electrocatalyst for the HER in seawater.

Cyclic (monoamino)carbenes, including cyclic (alkyl)(amino)carbenes (CAACs) and cyclic (amino)(aryl)carbenes (CAArCs), have been developed as ancillary ligands, mainly by taking advantage of their unique electronic properties such as strong nucleophilicity and electrophilicity in enhancing the reactivity of metals in organic transformations. This review focuses on the summary of recent developments by the use of CAACs and CAArCs as ligands in transition metal catalysis. It is organized by organic reactions that are promoted by CAAC- or CAArC-supported metal catalysis. A broad range of catalytic transformations that are promoted by CAAC-/CAArC-metal catalysis, including α-arylation of ketones, Mizoroki-Heck and Suzuki-Miyaura cross-coupling, Friedel-Crafts reaction, aerobic oxidation of aldehydes, hydrogenation of arenes and heteroarenes, functionalization of unsaturated C≡C, C=C, and C=X bonds, and olefin metathesis reactions, will be surveyed from the viewpoint of synthetic chemistry, mainly focusing on the discussion of the related reaction scope and catalytic mechanism for insight into the discovery of new transformations using these electron-rich carbene ligands.

Since their discovery, aptamers have steadily gained recognition as versatile molecular probes, with their significance further underscored by their inclusion in IUPAC’s Top Ten Emerging Technologies in Chemistry in 2024. Generated through the in vitro selection process, these oligonucleotides combine high specificity, synthetic versatility, and structural adaptability, enabling diverse applications in diagnostics, biosensing, and targeted therapeutics. While early expectations positioned aptamers as direct competitors to antibodies, practical challenges—such as susceptibility to nucleases and limited functionality in complex biological environments—have prompted a strategic shift toward specialized applications. Recent innovations highlight their unique strengths, including electrochemical biosensing, integration with dynamic DNA networks for signal amplification, and targeting membrane proteins or intracellular molecules. Rather than directly replacing antibodies, aptamers are increasingly being utilized in areas where their structural flexibility and programmability provide distinct advantages. This review discusses recent advancements in aptamer selection and explores emerging applications that harness their unique capabilities. By analyzing the evolving landscape of aptamer-based technologies, we highlight key opportunities for further development and translation into practical bioanalytical and biomedical solutions.

The hydrogenation of carbon dioxide (CO₂) to ethanol (EtOH) represents a promising strategy for carbon resource utilization. This progress advances the fields of green chemistry and renewable energy technologies. However, its practical implementation remains hindered by challenges in catalyst development, reaction mechanism elucidation, and industrial scalability. The reaction pathway for CO₂ hydrogenation to EtOH is intricate, involving C-O bond activation and C-C coupling, with its thermodynamic and kinetic properties strongly influenced by temperature, pressure, and catalyst structure. Briefly, CO₂ conversion rate and EtOH selectivity are significantly enhanced by optimizing catalyst active sites, incorporating promoters and selecting appropriate supports. In recent years, multifunctional catalysts have emerged as research hotspots due to their facile structural design and superior catalytic performance. Here, it reviews the reaction mechanisms, catalyst design principles, and optimization strategies for CO₂ hydrogenation to EtOH in the continuous-flow fixed-bed reactor with a particular emphasis on the roles of noble metals (e.g., Rh) and transition metals (e.g., Co, Cu) in this reaction. Future investigations should focus on deepening the mechanistic understanding of the reaction, developing efficient and stable catalysts, and optimizing the reaction conditions to enable the industrial-scale application of CO₂ hydrogenation to EtOH in the continuous-flow fixed-bed reactor, thereby advancing green chemistry and sustainable development.

Currently, the polymer PM6 stands out as one of the most efficient donor polymers in the field of organic solar cells, and many researchers are dedicated to further enhancing its photovoltaic performance. Among various strategies, the end-capping modification was a simple and effective way to minimize the undesired end-capping impurity groups and to narrow the molecular weight distribution of the final polymer donors. In this study, we systematically investigated the substitution effect of H, F, and Cl of the end-capping naphthyl group of the PM6 polymer on the photovoltaic performance. Compared to the naphthyl and fluoro-naphthyl group, the chloro-naphthyl moiety possesses a larger dipole moment, thereby enhancing the interaction between chloro-naphthyl end-capped PM6 with the small molecule acceptor, L8-BO, significantly reducing the π-π stacking distances between molecules and enhancing charge-carrier mobilities. Devices based on PM6-Cl:L8-BO exhibited appropriate phase separation, optimal molecular orientation, and minimal charge recombination. Consequently, the PM6-Cl:L8-BO-based device achieved an outstanding power conversion efficiency of 18.07%, with simultaneous enhancements in short-circuit current density (J_SC) and fill factor (FF). This was much higher than those of PM6-F:L8-BO-based (17.60%) and PM6-H:L8-BO-based (16.87%) devices. These results demonstrated that the modulation of end-capped atoms in PM6 could significantly improve the photovoltaic performance of organic solar cells and provide guidance for the design and synthesis of high- performance polymers.