Small Methods最新文献

Aqueous zinc-iodine (Zn─I₂) batteries demonstrate immense potential for energy storage owing to their inherent safety, stable voltage plateau, and environmental friendliness. However, the slow iodine conversion, polyiodide shuttle effect, and uncontrollable Zn dendrites impede the improvement of their performance. Herein, we successfully designed a bifunctional core-shell host derived from BiHCF@ZIF-8, which consists of a porous carbon matrix encapsulating abundant metal catalytic sites and trace N-doping (BZPC). This superior multi-site co-doped hierarchical porous structure can serve as a high-efficiency iodine carrier to effectively confine iodine species and enhance their conversion kinetics. Simultaneously, the BZPC can also be applied as a functional modification layer to induce uniform Zn deposition, thereby achieving a dendrite-free Zn anode. The assembled Zn//BZPC@I₂ batteries and BZPC@Zn symmetric cells can operate stably at ultrahigh current densities of 50 C and 100 mA cm^-2, respectively. Through a synergistic optimization strategy of "one host for dual purposes", the BZPC@Zn//BZPC@I₂ batteries achieve an ultralong lifespan of 28 000 stable cycles even at an ultrahigh current density of 50 C. This study not only pioneers the difunctional BZPC for both iodine host design and zinc interface engineering but also establishes an innovative and scalable strategy for developing long-life and high-rate Zn─I₂ batteries.

Combining functional magnetic resonance imaging (fMRI) with real‑time monitoring of neurochemicals, such as ions, offers powerful opportunities for multimodal investigation of brain function through simultaneous acquisition of local neurochemical dynamics and whole-brain neural activation patterns. However, current combination approaches predominantly rely on fluorescent calcium imaging, which cannot effectively capture diverse extracellular ion dynamics in deep brain regions, thereby constraining comprehensive studies of various neurological disorders and physiological state transitions. Here, implantable MRI-compatible fiber ion sensors (MISs) are developed to realize concurrent extracellular ion monitoring and fMRI. The MIS employs a simplified architecture with an ion-selective membrane conformally coated on a conductive polymer fiber that simultaneously serves as both an ion-to-electron transduction interface and an electrical conductor. This design enables stable, high-sensitivity monitoring of calcium and potassium ions while maintaining negligible imaging artifacts during 7 T MRI. As a proof of concept, concurrent monitoring of extracellular ion fluctuations via the implanted MIS and whole-brain fMRI is realized during anesthesia transitions in rats, establishing the MIS as an effective tool for multimodal exploration of neural activity.

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In article number 2500827, Jo and co-workers highlight the critical role of electrolyte composition in modulating the reactivity of crystal water at the Prussian blue (PB) cathode–electrolyte interface in sodium-ion batteries (SIBs). NaTFSI mitigates interfacial degradation by disrupting hydrogen-bond networks and suppressing water-mediated side reactions, whereas NaClO₄ intensifies water coordination, inducing cathode-electrolyte interphase instability. These findings provide valuable guidance for optimizing electrolytes in PB-based SIBs.

The instability of the electrode-electrolyte interface and sluggish kinetics in zinc metal batteries (ZMBs) accelerate their degradation. Modifying the interfacial layer and Zn²⁺ solvation structure presents promise for enhancing ZMBs' longevity. Herein, a high-entropy electrolyte is developed by incorporating multiple ether-based solvents, a fluorine-rich ether diluent, and H₂O as a co-solvent with Zn(BF₄)₂ salt. The diverse solvents enrich the coordination species in the Zn²⁺ solvation sheath, increasing the solvation entropy and minimizing solvent clustering. This enhanced solvation entropy weakens Zn²⁺-solvent interactions and facilitates the desolvation process, significantly accelerating interfacial reaction kinetics while maintaining low polarization. Additionally, the dissociated solvents and anions migrate to the electrode, yielding a robust and micron-thick ZnF₂ interfacial layer that suppresses zinc dendrite and byproducts. Notably, without compromising the anti-corrosion and anti-freezing properties, H₂O regulates the interfacial layer composition and structure through hydrolysis, ensuring a dense and uniform ZnF₂ layer. Consequently, within this high-entropy electrolyte, Zn/Zn symmetric cells provide stable cycling for over 2000 h (1 mA cm^-2 and 1 mAh cm^-2) without polarization. The high Coulombic efficiency of 99.55% in Zn/Cu asymmetric cells demonstrates the excellent reversibility of zinc plating/stripping. Moreover, Zn/polyaniline full cells achieve a lifespan exceeding 1000 cycles with promising capacity retention.

All-solid-state sodium-ion batteries (ASSSIBs) based on halide solid electrolytes (HSEs) are emerging as promising systems for high energy density and stable energy storage. Although HSEs are generally regarded as compatible with high-voltage oxide cathodes, their interfacial stability remains insufficiently understood. Here, we evaluate the interfacial chemical compatibility between representative HSEs and high-voltage sodium cathode materials through mutual decomposition reaction energy calculations. The analysis reveals interfacial instability of HSEs against high voltage cathodes, challenging the prevailing assumption of their intrinsic stability and highlighting the need for targeted interface design. To address this issue, a high-throughput computational screening of 12 800 sodium-containing compounds was performed, identifying several coating materials that effectively suppress interfacial reaction driving forces. These coatings promote stable SE-cathode interfaces, ensuring chemical compatibility under high voltage operation. This study establishes a strategic framework for interfacial design that deepens the understanding of HSE stability and advances the development of durable, high-energy ASSSIBs.

Trinuclear copper complexes that emulate the active sites of multicopper oxidases (MCOs) are of broad biological interest. Here, a monoatomic-node strategy combined with solvent reduction was used to construct a rare trinuclear copper MOF featuring a planar, equilateral-triangular Cu^I _0.6Cu^II _2.4 core. The Cu^I _0.6Cu^II _2.4-MOF nanozyme shows enzymatic activity 37.2 times than that of laccase and 13.6 times than that of a Cu^II ₃-MOF analogue, retains high chemical stability from pH 4 to 12, and lowers production cost by 16.2-fold relative to natural laccase. DFT calculations attribute the superior performance to the introduction of Cu⁺, which yields a more favorable electronic structure, reaction energy landscape, and intermediate binding than in Cu^II ₃-MOF. Consequently, Cu^I _0.6Cu^II _2.4-MOF efficiently degrades phenolic pollutants and enables colorimetric discrimination and detection of 11 phenols as a colorimetric sensor array. It also affords sensitive detection of epinephrine and dopamine, with limits of detection of 6.5 and 10 µm, respectively. Overall, this work demonstrates a laccase-inspired route to high-activity, low-cost MOFs with strong potential for environmental remediation and biosensing.

Aqueous rechargeable zinc metal batteries (ARZMBs) have attracted increasing attention as sustainable energy storage systems capable of mitigating the intermittency of renewable energy, due to their high safety, low cost, and environmental friendliness. However, their practical applications are still hindered by several critical issues, including poor low-temperature performance, slow ion diffusion of the electrolytes, and severe gas generation reaction at the interface between the electrolyte and the electrode. In recent years, the design concept of high-entropy electrolytes (HEEs) has been introduced into aqueous energy storage systems. By introducing diverse ions or solvent molecules, it is possible to enhance the entropies of the system, including configurational, tetrahedral, and mixing entropy, thereby enabling control over the solvation structure, hydrogen bond network, and interfacial reactions. However, the concept of entropy remains relatively abstract and challenging for newcomers to grasp. Moreover, the performance enhancements achievable through different types of entropy vary considerably, and a systematic review comparing these effects is currently lacking. This work reviews the fundamental principles of HEEs, strategies for entropy modulation, and recent advances in their applications for ARZMBs. Special emphasis is placed on the mechanisms by which configurational entropy optimizes the Zn²⁺ solvation structure, as well as the role of tetrahedral entropy in modulating the hydrogen bond network. Finally, we discuss the challenges and future directions for HEEs in the development of high-performance, wide-temperature-range, and long-lifespan ARZMBs, with the aim of providing theoretical guidance to advance green energy storage technologies.

The stringent safety protocols required for hydrofluoric acid (HF) based MAX phase etching and the reliance on material characterization tools such as XRD, SEM, EDS and XPS to study etching make the MXene research challenging. Here, we have employed ²⁷Al NMR spectroscopy for the rapid detection of selective etching, directly from the etching supernatant, of soluble aluminum species generated during the MAX phase etching reaction. This technique was applied to the development of a new etching protocol for Ti₃AlC₂ MAX phase using the less hazardous hexafluorosilicic acid. The etching process was studied using a combination of ²⁷Al and ¹⁹F NMR spectroscopies where it was demonstrated to be free of HF or free fluoride in quantities detectable by ¹⁹F NMR, and that the primary etching byproduct is H₃AlF₆. ¹⁹F NMR spectroscopy was additionally proven to be a viable technique to quantify the extent of etching using trifluoroacetic acid as an internal standard.

Nanoparticle (NP) fabrication has advanced rapidly, driven by the growing role of nanomedicine in targeted drug delivery. Each fabrication strategy offers unique advantages and limitations. Here, we conduct a comparative evaluation of three prominent methods: turbulent jet mixing, microfluidic mixing, and extrusion, for producing biomimetic nanoparticles (BNPs). BNPs are emerging as next-generation drug delivery platforms, combining liposomal biocompatibility with enhanced cellular uptake, prolonged circulation, and selective targeting, achieved by incorporating membrane proteins from source cells into synthetic lipid bilayers to confer cell-mimicking functionality. Using neuron-derived BNPs ("Neurosomes") as a model, we systematically assess physicochemical and biological properties across fabrication methods and their impact on BNP function. Turbulent jet and microfluidic mixing produce BNPs with superior stability, higher membrane protein incorporation, improved batch-to-batch reproducibility, and enhanced targeting, whereas extrusion leads to diminished performance due to shear-induced protein loss. Notably, this study presents the first application of high-resolution LC-MS/MS proteomics to quantitatively compare membrane-associated protein profiles across fabrication methods. These results highlight the critical influence of fabrication techniques on BNP structure and function and provide actionable insights for optimizing production strategies, facilitating the scalable development of targeted nanotherapeutics.

Two-photon polymerization (TPP) enables ultrahigh-resolution 3D printing but faces challenges in mechanical robustness and microfluidic integration. By introducing hydrogen bonds, materials can exhibit high mechanical strength and hydrophilicity. Here, a novel photosensitive resin was reported, termed BUM, engineered by blending a urea-pyrimidinone-containing monomer with bisphenol A glycerolate diacrylate. BUM resin has a fracture elongation of 17.5%, a fracture strength of 98.5 MPa, a toughness of 10.3 MJ m^{- 3}, a modulus of 6.33 GPa, and a hardness of 0.30 GPa, exhibiting high mechanical strength. Its printability across submicron to millimeter scales has been verified through complex structures. Simultaneously, mimicking the properties of biomass materials, a high density of hydrogen bonds was introduced into the photosensitive resin to enhance its performance in hydrophilic environments. By leveraging biomimetic principles in both structural and material design, a pointed cone structure inspired by wheat awns was developed, achieving a reverse gravity unidirectional water transport of 4.17 mm s^-1, which is 6.4% higher than the control group. This synergy of intrinsic material enhancement and structural design unlocks multifunctionality for microfluidics and directed liquid transport. This work demonstrates new application potential for hydrogen bonding engineering resins used in high-strength, functional microdevices.