ACS Materials Letters最新文献

Lithium extraction from naturally occurring α-spodumene is hindered by poor lithium diffusivity, necessitating high-temperature phase transformation to a low-density β polymorph. Although β spodumene exhibits up to 5 orders of magnitude higher lithium-ion diffusivity, both phases have diffusion activation energies between 0.8 and 1 eV, indicating that polymorph density is not the controlling factor over diffusivity. We show that aluminum vacancies facilitate lithium-ion diffusion in α-spodumene by reducing the migration barrier from 2.4 to 0.9 eV. Bond valence site energy and nudged elastic band calculations show a new lithium local minimum site which promotes a one-dimensional percolation network by reducing the lithium intersite distance from 4.5 Å to 2.9 Å. However, aluminum vacancies are energetically unfavorable to percolate through the whole structure, resulting in very low net lithium diffusivity and highlighting the critical role of nonstoichiometric defects in facilitating lithium transport in rigid aluminosilicate structures.

Keratin holds significant potential for biomedical applications due to its superior cytocompatibility and ability to promote cellular migration and differentiation. However, despite these advantages, keratin processing is difficult due to its limited solubility in water and most common organic solvents. Herein, a sustainable and cost-effective approach was used for chicken feather dissolution (a keratin-rich waste) using acetate-based ionic liquids. This method simplifies the development of three-dimensional (3D) structures via directly embedded 3D printing keratin dissolved in ionic liquids (ILs). Using a carbonate-bicarbonate agarose microparticle support bath, we successfully promoted disulfide exchange and direct cross-linking of printed structures with diverse patterns and geometries, exhibiting excellent structural integrity. A comprehensive analysis of the rheological, mechanical, and biological properties was conducted, highlighting their potential biomedical applications. Interestingly, the scaffolds exhibited a dynamic shape-change over time, mediated by cellular traction forces, demonstrating their potential for 4D printing toward innovative bioapplications.

Superatomic crystals comprising ligand-capped, metal chalcogenide clusters and fullerenes are modular materials that exhibit enhanced electronic, magnetic, and thermal conductivity properties. We find that neutral, M₄S₄ (M = Fe, Co) clusters stabilized with N-heterocyclic carbenes (NHCs) can transfer charge to C₆₀ fullerene to form binary superatomic crystals. Notably, these compounds are soluble in various organic solvents, allowing their properties to be investigated in solution, unlike traditional fullerene-based superatomic crystals. The ion pairs can be further assembled into organometallic polymers using Janus-bis(NHCs) to cross-link the oxidized M₄S₄ units. We show that the superatomic polymers are more conductive than both the precursor superatomic crystals and the polymers containing only neutral M₄S₄ clusters. Similar conductivity values can be obtained when neutral M₄S₄–NHC polymers are doped with solutions of C₆₀ fullerene. These findings demonstrate that next generation superatomic materials can be prepared via the combination of charge transfer and polymerization with appropriate cross-linking agents.

Immobilized enzymes constitute a class of composite biocatalysts whose performance is governed by both enzyme molecules and carrier materials. Recent advances in materials science have yielded diverse novel porous materials, with covalent organic frameworks (COFs) emerging as particularly promising candidates for enzyme immobilization carriers. This review systematically categorizes COF synthesis strategies based on elemental composition, encompassing boron-containing, nitrogen-containing, and novel metal-containing COF variants. Enzyme immobilization techniques on COFs are classified into postsynthesis and presynthesis approaches. Furthermore, methodologies for constructing diverse building blocks and critical linkage structures are summarized, alongside detailed elucidation of pore structure modulation techniques─including topological design, template-assisted methods, and defect engineering─employed to enhance compatibility with enzyme dimensions. Finally, emerging types and application scenarios of immobilized enzyme-COF composite systems are analyzed, emphasizing the critical importance of rational design and recoverability in advancing practical application potential.

Wearable sweat sensors (We-SS) enable noninvasive health monitoring by detecting sweat biomarkers. A bibliometric analysis of 1,006 Scopus-indexed articles (2005–2024) shows 60.9% of publications and 66.5% of citations from 2022–2024, indicating rapid growth. China and the United States lead, with strong global collaboration. We-SS detect electrolytes (Na⁺, K⁺, Cl^–, 10–120 mM), metabolites (lactate, 2–30 mM; glucose, 10–200 μM; uric acid, 2–200 μM), hormones (cortisol, 0.1–25 ng/mL), and trace metals (Zn²⁺, Cu²⁺, 100–1,000 μg/L) using graphene, MOFs, PEDOT:PSS, and electrochemical methods. AI/IoT integration enhance predictive diagnostics. We-SS market is projected to grow from USD 4.41 billion (2024) to USD 13.47 billion (2034) at a 11.8% CAGR, driven by preventive medicine, sports, and chronic disease management. Challenges include analytical interference, calibration stability, durability, and biocompatibility. Future innovations involve advanced nanomaterials, self-calibrating systems, robust encapsulation, and biocompatible coatings, positioning We-SS for personalized healthcare.

Copper plays a critical role in sustaining the activity of enzymes and transcription factors vital to tumor cell proliferation while also regulating signaling networks that preserve cellular homeostasis. However, intracellular copper levels exceeding threshold tolerances can disrupt metabolic processes and trigger cuproptosis, which is a novel, characterized copper-dependent form of regulated cell death. This mechanistically distinct pathway offers a promising therapeutic strategy for selectively targeting malignancies by exploiting mitochondrial copper dysregulation under both physiological and pathological conditions. The burgeoning interest in cuproptosis underscores its broad potential for clinical translation in oncology. In this review, we have synthesized recent advances in the design of antitumor nanomaterials engineered to trigger cuproptosis, while systematically evaluating synergistic therapeutic modalities that could amplify their efficacy. We further discuss unresolved challenges and emerging opportunities to optimize copper-mediated oncologic interventions.

The integration of solid-state inorganic fillers into polymer matrices can improve the performance of solid lithium metal batteries. However, there is poor interface interaction between the polymer matrix and solid-state inorganic fillers, which has led to the performance of solid lithium metal batteries falling far short of expectations. Here, we constructed a bridging interaction based on borate ester dynamic cross-linking to prepare a supertough and self-healing poly(vinylidene fluoride)-hexafluoropropylene/graphene oxide/borate bonds/Li_6.5La₃Zr_1.5Ta_0.5O₁₂ solid polymer electrolyte. The electrolyte exhibits a wide electrochemical window (4.84 V), high elongation at break (205%), outstanding thermal stability (200 °C), and high-capacity retention (90.3% after 900 cycles under 2C). We further revealed the influence of borate ester dynamic cross-linking on the performance of solid polymer electrolyte through density functional theory calculations. This work offers insight into designing high-performance solid polymer electrolytes for solid-state batteries.

Growing environmental concerns have driven the search for sustainable wastewater treatment solutions, particularly for removing persistent synthetic dyes. This study explores hydrogels made from squid pen protein (SPP) and chitosan, biodegradable polymers, for anionic dye adsorption─reactive blue 4 (RB4) and methyl orange (MO). A 50%/50% SPP/chitosan hydrogel was optimal for RB4 adsorption while minimizing chitosan use. Adsorption followed the Langmuir model, with capacities of 151.52 mg/g for RB4 and 54.94 mg/g for MO. Optimal RB4 adsorption conditions were 65 °C, 6 h, pH 7, and 0.2 wt % adsorbent at 300 rpm. Kinetic analysis indicated a pseudo-second-order model, suggesting chemisorption. Characterization (FT-IR, SEM, XPS) revealed functional groups and binding mechanisms, with XPS confirming a nucleophilic attack between the amino groups of chitosan/SPP protein and RB4’s dichlorotriazine moiety. Higher cross-linker content reduced adsorption. This study demonstrates SPP/chitosan hydrogels as a cost-effective, sustainable alternative for wastewater treatment.

A promising strategy for next-generation energy storage involves boosting the energy density through innovative cell architectures. Among these architectures, anode-less Li metal batteries stand out for their potential to eliminate excess Li, thus maximizing energy density and simplifying manufacturing. Most anode-less systems rely on liquid or inorganic solid electrolytes, each with safety and scalability limitations. This work demonstrates the feasibility of an anode-less system enabled by garnet-based composite polymer electrolytes with high ionic conductivity (∼1.4 mS cm^–1 at 50 °C). A Cu–In current collector on the anode side was optimized to promote uniform Li nucleation and alloy formation. Full cells exhibited stable cycling for 200 cycles, with an average Coulombic efficiency of 96.2%. Although this work did not target high capacity, it provides a crucial proof of concept, highlighting the practical viability of a polymer-based anode-less Li metal battery for future high-energy-density battery systems.

Current electrolytes for calcium batteries (CaBs) rely on cumbersome salt synthesis, hindering research and development. As a subclass of CaBs, calcium metal batteries (CMBs) could potentially offer high energy density due to their use of a calcium anode. However, realizing this advantage remains difficult, largely due to calcium’s electrochemical instability. To address these challenges, we introduce a family of electrolytes made entirely from commercially accessible Ca-salts and solvent mixtures and further demonstrate stable cycling of symmetric Ca||Ca cells using only a solvent mixture, without added salt (i.e., not being an electrolyte on its own). Notably, this cycling stability extends to CMB full cells using low salt concentration electrolytes (e.g., 0.1 M Ca(OTf)₂ in NMA:TMP), and similar full cell performance is also achieved using other combinations of salts and solvent mixtures. Extensive electrochemical testing confirms stable cycling under diverse and challenging conditions. Overall, our findings reframe electrolyte design principles and pave the way for practically useful CMB cells.