ACS Materials Letters最新文献

The mechanochemical synthesis of halide-based solid-state electrolytes (SSEs) requires the fine-tuning of key parameters to optimize ionic conductivity, yet rigorous statistical analysis of the parametric effects remains lacking. In this work, we applied an orthogonal design of experiments on Li₂ZrCl₆ (LZC) – a cost-effective halide-based SSE – to evaluate the impact of six parameters. The results reveal that ionic conductivity is most influenced by the ball-to-precursor mass ratio, the ball-mill step time, and the milling speed. Structural characterizations indicate a resistive intermediate spinel-LZC phase that inhibits performance. A multivariate linear regression model was employed to quantify the impacts of the parameters. Finally, a Gaussian process regression model predicted an optimized ionic conductivity and its corresponding set of synthesis conditions. The findings reported here establish a hierarchy of the importance of parameters for experimental optimization of current and future SSEs to enable consistent, high-quality production for next-generation all-solid-state Li-ion batteries.

High rates of the lithium redox-mediated nitrogen reduction reaction (Li-NRR) typically require significant overpotentials >0.5 V, limiting energy efficiency of the process. Aiming to accelerate the Li-NRR at low overpotentials, we used nickel cathodes modified with a layer-expanded molybdenum disulfide (MoS₂^LE). Under 15 bar of N₂ and an apparent Li-NRR overpotential of 0.2 V, the MoS₂^LE/Ni electrodes produce NH₃ at an improved yield rate of 90 ± 20 nmol s^–1 cm^–2 and faradaic efficiency of 57% ± 2%, as compared to 39 ± 4 nmol s^–1 cm^–2 and 39 ± 5% for unmodified Ni (in 2 M lithium bis(trifluoromethylsulfonyl)imide + 0.1 M C₂H₅OH tetrahydrofuran solutions). Characterization of the electrodes suggests that the improved performance stems from the transformation of MoS₂^LE into (poly)sulfide species within the solid electrolyte interphase (SEI). These results broaden our understanding of the Li-NRR performance-SEI relationships, which support the development of practical ammonia electrosynthesis technologies.

Li metal anodes are essential for high-energy-density all-solid-state batteries (ASSBs) but suffer from dendrite growth and interfacial instability. Here, a Si@CNT interlayer is introduced to enhance interfacial contact and Li-ion transport. The Si@CNT composite, prepared via scalable spray drying, undergoes in situ lithiation during cell assembly, forming a conductive and lithiophilic Li_xSi phase with an embedded carbon nanotube (CNT) network. This structure suppresses dendrite formation, mitigates electrolyte decomposition, and promotes fast Li transport. Li symmetric cells exhibit high critical current densities of 4.5 mA cm^–2 at 45 °C and 8.0 mA cm^–2 at 80 °C with stable cycling over 800 h. Full cells show 84% capacity retention after 200 cycles and deliver ∼171 mAh g^–1 at 10C, outperforming bare Li- and Si-only references. These results demonstrate a scalable interfacial strategy for high-rate, long-life ASSBs.

Photothermal superhydrophobic coatings suffer performance degradation in low-temperature, high-humidity environments due to vapor-condensation-induced mechanical interlocking within micro/nanostructures. Inspired by the interconnected porous network of dictyophora, we engineered a multifunctional biomimetic coating (PSPA) by incorporating polydopamine (PDA) into a low-surface-energy polymer network and precisely regulating microphase separation to construct a dictyophora-mimetic interconnected microporous architecture. This bioinspired design enables efficient vapor transport (29.8% transmission rate of ordinary cement boards), effectively suppressing vapor condensation and ice-substrate mechanical interlocking under harsh conditions while extending the static icing delay time to 674 s. Simultaneously, synergistic photothermal conversion via multiscale PDA and hierarchical micro/nanostructures achieves rapid active deicing within 20 s, with the interconnected network further imparting exceptional mechanical/chemical stability. This work establishes a new paradigm for highly efficient, reliable anti/deicing coatings in aerospace and extreme environments.

Bacterial biofilm significantly hinders the penetration of antimicrobial agents, making bacterial clearance challenging and leading to persistent biofilm-associated infections. A precise combination of phototherapeutics and chemotherapy can synergistically improve the therapeutic outcome and thereby may overcome drug-resistant bacteria through a multipronged assault. Herein, a nanophotosensitizer (BHZnC) was developed through a multicomponent self-assembly strategy, incorporating phototherapeutics and antimicrobial peptides, coordinated with Zn²⁺ and modified with benzoxaborole-conjugated histatin-5 (BHst-5) and Chlorin e6 (Ce6). This innovative system not only effectively penetrates biofilm matrices but also prevents degradation of Hst-5 by proteases secreted by Candida albicans (C. albicans). The binding of Hst-5 with Zn²⁺ promotes microbial membrane fusion and rupture, thereby enhancing the bactericidal efficacy. In vivo studies demonstrate that the combination of chemotherapy and phototherapeutics exhibits a superior antibiofilm performance against a drug-resistant bacteria model attributed to their synergistic anti-infection efficacy.

Compared to other synthetic routes, electrochemical synthesis offers unique control of the reaction rate, or current density J. Recently, interest in electrochemical crystallization from aqueous electrolytes has resurged, driven in part by water’s inherent reactivity. Spontaneous proton production (H₂O ↔ H⁺ + OH^–) presents both challenges and unique opportunities. In this Review, we first explore the key physicochemical processes involved in aqueous electrocrystallization of metals, a simpler group of materials with well-defined lattice structures. We then turn our attention to critical considerations for growing more complex compounds, characterized by intricate lattice symmetries and stoichiometries. We argue that achieving precision control in aqueous electrochemical crystallization requires a holistic understanding of proton activity and the ability to regulate interfacial chemical kinetics and transport phenomena across multiple length scales. With such control, electrochemical crystallization in aqueous systems offers a sustainable platform for the precision synthesis of materials essential to energy technologies and sustainability.

Sorafenib (Sfb) is a widely used chemotherapy drug for the clinical treatment of hepatocellular carcinoma (HCC); however, its therapeutic effect is often hindered by inherent nonspecific toxicity and hypoxia-induced epithelial–mesenchymal transition (EMT). Besides, its inhibition of tumor angiogenesis further aggravates hypoxia, intensifying this challenge. Herein, we have developed a tumor-activatable Sfb prodrug (Sfb-Fca) to reverse the hypoxic tumor microenvironment for EMT alleviation and enhance therapeutic outcomes in HCC. Sfb-Fca consists of two components: the major moiety (Sfb) and the ferrocene acid (Fca) moiety, linked via a thioketal bond. This bond is cleaved in the presence of the elevated H₂O₂ levels typical of cancer cells, releasing Sfb for chemotherapy and Fca for hypoxia modulation. Fca catalyzes the production of O₂ via a Fenton-like reaction, alleviating tumor hypoxia, reducing intracellular levels of HIF-1α and ZEB1 protein, and synergistically enabling effective chemodynamic therapy for enhancing the therapeutic effects of Sfb.

Under concentrated sunlight with a high operation temperature (>100 °C), the enthalpy reduction performance of interfacial materials still remains largely unexplored, which is crucial for future large-scale industrial seawater desalination. Here, an interfacial material that can reduce the evaporation enthalpy under high solar concentration was developed by chemically grafting cyclodextrin (CD) onto porous MnO₂ (β-CD-MnO₂). Experiments demonstrate a 31.5% reduction in the evaporation enthalpy in the β-CD-MnO₂ system, which has an evaporation rate of 1.76 kg·m^–2·h^–1. Our molecular dynamic simulations reveal that the enthalpy reduction arrives from the existence of water-cluster evaporation promoted by the intermediate water. The large existence of intermediate water content in β-CD-MnO₂, which was observed in REMAN measurements, is attributed to the heterostructures, the silane linker, and the ring structure of cyclodextrin in β-CD-MnO₂. Both outdoor experiments and concentrated solar experiments (13 suns) demonstrate that the β-CD-MnO₂ evaporator could realize highly efficient interfacial evaporation with stable enthalpy reduction characteristics.

The growing demand for high-speed communication and highly integrated electronic devices has emphasized the importance of low-dielectric insulator materials. Herein, we present a facile molecular design strategy for poly(aryl ether ketone)s that simultaneously reduces the dielectric constant (D_k) and loss (D_f). The incorporation of bulky cyclohexane side groups increased the intrinsic free volume while limiting additional relaxation. Selective methyl substitution further modulated dielectric properties; methyl groups on cyclohexane groups increased the free volume, whereas those on aromatic rings restricted the chain mobility. Dispersion-corrected density functional theory single-point calculations revealed a high torsional barrier for aromatic methyl groups, consistent with the restricted rotational motion. Consequently, the resulting polymer exhibited low D_k and D_f values (2.65 and 0.0021, respectively) at 28 GHz. These dielectric property improvements were achieved by preserving the mechanical and thermal stabilities of the films, indicating the effectiveness of precise molecular design for next-generation low-k polymers.