Xiamen Institute of Rare-earth Materials

Iron-based Prussian blue analogues (PBAs) are promising cathode materials for sodium-ion batteries owing to their low cost and high theoretical capacity. However, their practical capacity is often hampered by a high lattice water content and structural defects. While the use of complexing agents and elemental substitution can mitigate these issues, the subsequent difficulty in recovering these complexing agents raises costs and hinders industrial scalability. To address this challenge, we present a novel oxalate-assisted kinetic synthesis route. This method leverages the slow dissolution of metal oxalate precipitates to gradually release Fe2+ and Mn2+ ions, which then coordinate with ferrocyanide ions to form PBAs. This controlled release kinetics eliminates the need for extraneous complexing agents, enabling the preparation of high-sodium-content, low-defect PBAs. By optimizing the Mn/Fe ratio, we found that the sample with 20% Mn doping (PBA@20% Mn) delivers an excellent specific capacity of 115.5 mAh g–1 at 0.2 C and retains 85.6% of its initial capacity after 500 cycles at 5 C. Ex-situ XRD analysis reveals highly reversible (de)sodiation processes with no significant phase transitions, accounting for the superior cycling stability. Furthermore, the oxalate in the mother liquor can be filtered and reused to produce high-quality PBAs, thereby demonstrating a consistent closed-loop process. This work not only provides a strategy for synthesizing high-performance PBAs but also proposes a green, cost-effective pathway for their industrial production.

Polymer fibers that have the most industrial potential for uranium enrichment in seawater suffer from low adsorption site utilization because the polymer chains are often entangled due to intra-molecular interactions. Herein, a branched-linear intertwining electrospun fiber (PAN-bPEI-T/PVA) is obtained by co-grafting hyperbranched polyethyleneimine (bPEI) and linear triethylenetetramine (TEPA) for harvesting uranium from seawater. The fiber features a dendritic topology structure with a high density of distributed amino functional groups, which provide extensive pathways for uranium transport and contact. Meanwhile, the linear TEPA modulates the hydrogen bonding network by converting the strong intramolecular hydrogen bonds in bPEI into intermolecular hydrogen bonds, thereby enhancing the permeability and exposing more active sites. Compared to conventional bPEI polymer, the PAN-bPEI-T/PVA demonstrates higher accessibility and utilization of sites, achieving a capacity up to 806.4mg g-1 in uranium-spiked seawater, surpassing that of bPEI fiber by 2.5 times. The fiber retains over 95% capacity even after 7 cycles, demonstrating excellent reusability. Quantum-theoretical studies reveal that the flexible TEPA can form a synergistic adsorption network with bPEI, which undergoes adaptive adjustment in seawater to capture uranyl, improving both uranium uptake and selectivity. The proposed underlying mechanism of branched-linear intertwining provides a practical approach for designing high-performance uranium adsorbents.

Podocarpus nagi is a type of macrophanerophyte in the genus Podocarpus, belonging to the family Podocarpaceae. Its roots, branches, leaves, and seeds are rich in various chemical components, including nagilactones, flavonoids, steroids, diterpenoids, lignans, fatty acids, and sugars, which contribute to a broad spectrum of pharmacological activities, such as antioxidant, antitumor, and anti-inflammatory effects, and protection of the blood and nervous systems. It has long been used as a medicinal herb in Yao folk medicine for the treatment of trauma, bleeding, fractures, fox odor, eye diseases, colds, and other conditions. In this work, we comprehensively summarize the progress in the chemical composition and pharmacological activities of Podocarpus nagi, providing a reference for its further development.

Iron-based Prussian blue analogues (Fe-PBAs) have garnered significant attention as cathode materials for sodium-ion batteries due to their high specific capacity (∼170 mAh g–1), environmental compatibility, and cost effectiveness. However, their performance is hindered by substantial crystalline water and structural defects, which result in the insufficient electrochemical activity of FeLS(C). The low contribution of FeLS(C) to the overall capacity, compared to FeHS(N), results in diminished battery performance and rapid cycling degradation. This study presents an innovative synthesis strategy for low-defect, high-sodium-content nanoporous Prussian blue using an oxalic acid-assisted single-iron-source method. Subsequent heat treatment effectively removes crystalline water and introduces a controlled number of defects, further modulating the nanoporous architecture and activating the FeLS(C) capacity. The resulting thermally treated nanoporous material (PBA-HT) exhibits a high stable discharge capacity of 120.2 mAh g–1, an initial Coulombic efficiency of 95.4%, and an outstanding cycling stability (70.3% capacity retention after 1000 cycles at 5 C). Density functional theory calculations reveal that heat treatment reduces the crystal field energy, thereby activating FeLS(C). In situ electrochemical impedance spectroscopy and galvanostatic intermittent titration technique analyses confirm a significant enhancement in diffusion kinetics, facilitated by the optimized nanoporous structure, following thermal treatment. Moreover, PBA-HT demonstrates stable operation at extreme temperatures (−20 and 50 °C), highlighting its practical potential and offering a synthesis strategy for high-performance nanoporous Prussian blue analogues.

Copper(i) complexes are cost-effective and eco-friendly emitters, yet their device applications are hindered by broad emission, by limited film-forming ability, and especially by severe excited-state distortions that typically lead to low emission efficiency in the film state. Herein, to address these challenges, we propose a structural design strategy for highly efficient and sublimable copper(i)-bromide clusters by simultaneously incorporating donor–acceptor bisphosphine ligands and introducing ortho-methyl substitution. This design effectively suppresses intrinsic nonradiative decay by modulating the excited-state geometry, thereby achieving an exceptionally high photoluminescence quantum yield of 99% in doped films. Vacuum-deposited organic light-emitting diodes (OLEDs) using the optimized cluster [dtpb-Ac]2Cu2Br2 as the terminal emitter achieve efficient green emission with a maximum external quantum efficiency (EQE) of 25.1%. Notably, an innovative strategy exploits the intrinsically broad emission of the copper(i)-bromine cluster to sensitize the deep-blue MR-TADF emitter ν-DABNA, achieving high-efficiency green-sensitized blue OLEDs with a maximum EQE of 28.7% and Commission Internationale de l’Eclairage (CIE) coordinates of (0.15, 0.19). As either a green dopant or a sensitizer, the device performance ranks among the best reported for copper(i)-based OLEDs. The current study presents promising molecular design and sensitization strategies to address the key challenges in developing high-performance copper(i)-based OLEDs.