ACS Materials Letters最新文献

Bacterial infections in plants threaten oxygen production, food security, and economic stability, challenges exacerbated by biotic and abiotic stresses. Innovative approaches are urgently needed to protect plant health. Synthetic macromolecule systems have previously advanced protection in the biomedical field but plant-specific strategies remain underexplored. This study describes an antibacterial polymer synthesized through ring-opening metathesis polymerization using a norbornene quaternary pyridinium monomer and its application to living Nicotiana benthamiana plants via spray coating. The polymer displayed antibacterial efficacy, as evidenced by inhibition of microbial growth in liquid media, against Escherichia coli and Staphylococcus aureus, as well as inhibition of Agrobacterium infection in planta. Postapplication plant health was confirmed by measuring chlorophyll content and reactive oxygen species levels. Additionally, the coated plants exhibited enhanced drought resistance. These findings underscore the polymer’s efficacy in mitigating bacterial infections while preserving plant health, offering a viable strategy for integrated disease and drought management.

A controlled disordered-to-ordered phase transition offers a promising approach for designing catalysts for water electrolysis. Starting from disordered face-centered cubic (fcc) Pd, an ordered tetragonal Pd_1.06Cd_0.94 intermetallic alloy forms at 220 °C. Introducing Zn increases the ordering temperature, yielding tetragonal Pd_1.02Cd_0.968Zn_0.012 only at 260 °C. At 220 °C, an intermediate-composition (PCZ-mix-1) contains 69.4 wt % fcc Pd_0.51Cd_0.47Zn_0.02 and 30.6 wt % ordered tetragonal Pd_0.98Cd_1.02. PCZ-mix-1 nanoparticles exhibit superior alkaline hydrogen evolution reaction (HER) activity, driven by charge transfer across disordered–ordered interfaces. At the fcc–tetragonal interface, charge accumulation on Pd and depletion on Cd favor *H adsorption at the Pd sites and *OH at the Cd sites. PCZ-mix-1 delivers 36 ± 8 mV and 173 ± 10 mV overpotentials at 10 and 100 mA cm^–2, respectively, high mass activity (111.9 A g^–1), turnover frequency (TOF; 1.2 H₂ s^–1), and hydrogen evolution of 52 mL h^–1 at −250 mV_RHE, maintaining stability for >200 h at −0.175 V_RHE.

Metal oxide semiconductors (OSs) are now facing a new paradigm across wide research communities beyond the display industry. Despite the literature on ferroelectric thin-film transistors (FeTFTs) using fluorite-structured materials, the wide-bandgap nature and oxygen vacancy (V_O) of OSs are challenges to realize high-performance FeTFTs. In this paper, a metal oxynitride semiconductor (ONS) featuring a narrow bandgap and V_O tolerance was integrated with a HfZrO_x (HZO) thin film. A two-terminal (2T) ferroelectric diode (FD) which does not require thin HZO and selector was fabricated, showing anticlockwise hysteresis with an on/off ratio of ∼5 × 10⁴ and excellent uniformity. An HZO/ZnON FD exhibited polarization-dependent resistive switching, and multilevel nonvolatile characteristics were utilized for neuromorphic computing. This study investigates an HZO/ZnON ferroelectric device and its operation as an artificial synapse, which has rarely been reported so far.

Quantum dots (QDs), valued for their distinctive luminescent properties and size-dependent emission spectra, have garnered considerable attention in polymer chemistry. In line with this interest, the review highlights their role in reversible deactivation radical polymerization techniques, specifically atom transfer radical polymerization (ATRP) and reversible addition–fragmentation chain transfer polymerization (RAFT). Various types of quantum dots (QDs) and their ability to mediate photoinduced electron transfer (PET), as well as their potential for polymer grafting, are discussed, including semiconductor QDs, silicon quantum dots (Si-QDs), and carbon quantum dots (CQDs), the latter being the most extensively studied. Moreover, the role of QDs photocatalysts in photoATRP, metal-free ATRP (o-ATRP), and PET-RAFT is explored thoroughly, along with the impact of doping and confinement modifications on their performance. Additionally, the review covers subsequent functionalization with initiation sites or chain transfer agents for surface-initiated ATRP or RAFT, highlighting their possible applications.

Pulmonary fibrosis (PF) is a chronic, progressive, and fatal disease characterized by lung tissue destruction and scar formation, with conventional treatments unable to halt its progression. This study examines the mechanical microenvironment in PF, emphasizing its role in pathogenesis, including altered matrix stiffness, disrupted mechanical signal transduction via mechanosensitive ion channels (e.g., Piezo1, TRPV4) and pathways (e.g., YAP/TAZ, TGF-β/Smad), and its relevance to biomaterial design and precision-targeted therapy. This study highlights biomaterials such as photoresponsive hydrogels with tunable stiffness and RGD-modified peptide hydrogels that modulate cell–extracellular matrix (ECM) interactions, along with targeted therapies including ion channel inhibitors and pathway antagonists. Collectively, these insights lay the groundwork for mechanics-based treatments and functional biomaterials, advancing precision regenerative medicine for PF.

Hydrogen peroxide (H₂O₂) is widely used as a green oxidant and renewable energy carrier in environmental remediation and other fields. Photocatalytic and electrocatalytic synthesis of H₂O₂ offers a promising route for on-demand and in situ production, while the pursuit of efficient and stable catalysts has spurred exploration of metal–organic frameworks (MOFs), whose tunable structures and multifunctionality meet the requirements for efficient H₂O₂ generation. This work provides a comprehensive analysis of the fundamental mechanisms underlying photocatalytic and electrocatalytic H₂O₂ production. It systematically reviews recent advancements in MOF structural optimization for H₂O₂ synthesis, emphasizing strategies such as connector functionalization, interface engineering, defect engineering, and metal loading, as well as the influence of the chemical environment on reaction pathways and catalytic behavior. Furthermore, particular attention is given to the recent advances in MOF-based materials for in situ Fenton systems, in which photocatalytic and electrocatalytic H₂O₂ generation is applied to the degradation of organic pollutants.

The manifold tunable properties of nanoporous carbon materials, including high surface area, stability, conductivity, rich surface chemistry, and biocompatibility, render them a perfect platform for energy applications, catalysis, nanoseparation, and drug delivery. Here, we construct models of nanoporous carbon materials and unveil the molecular determinants of solvent nanoseparation and diffusion using coarse-grained molecular dynamics. The best nanoseparation is achieved with pore diameters just above size exclusion, and surface oxidation is the major selective modifier of diffusion of polar molecules in solvent mixtures. The shape of the solvents and, less significantly, the geometry of the pore network also influence nanoseparation. The derived Markov state model estimates the probability of a molecule following a certain path in the material. Our framework for material construction, simulation, and analysis provides a robust foundation for future investigations on how nanoseparation in nanoporous materials is governed by the interplay of surface chemistry, pore geometry, and molecular properties.

Understanding atomic-scale fluctuations in semiconductor quantum dots (QDs) is crucial for optoelectronic material design. We combine ab initio methods and Atomistic Line Graph Neural Networks (ALIGNN) to predict femtosecond time-resolved electronic properties in technologically relevant Cd₂₈Se₁₇X₂₂ QDs (X = Cl, OH). These models reveal weaker vibronic coupling in Cl-passivated QDs, highlighting ligand-dependent electron–phonon interactions. ALIGNN models with ensemble learning trained on only ∼10–17% of available data accurately predict bandgap and gap above the conduction band edge (ΔE_gap) (MAE < 2.8 meV) across long MD trajectories. Transfer learning extends accurate electronic structure predictions to new trajectory segments with minimal retraining. The Feature Nullification Analysis framework uniquely links transient electronic properties, especially trap state formation, to atomic environments. While bandgap dynamics depend on localized atomic sites, ΔE_gap stems from distributed ones. Such a scalable, atom-resolved methodology efficiently probes long-time-scale quantum dynamics, offering atom-resolved insights for designing optoelectronic nanomaterials.

Developing efficient ultraviolet (UV) organic light-emitting diodes (OLEDs) with narrowband emission approaching 380 nm remains an important and challenging issue despite their promising applications in biology, chemistry, industry, and healthcare. Herein, two donor–acceptor (D–A) type aggregation-enhanced emission (AEE) active emitters 3,6PC9N and 3,6PC9D, featuring hybridized localized and charge transfer states, are developed by connecting small-sized acceptors (cyanobenzene or pyrimidine) to a three-dimensional rigid and bulky carbazolyl donor, where the molecular packing modes are manipulated precisely. The resulting doped OLEDs demonstrate significant narrow UV light with peaks of 384 and 379 nm, full width at half maximum values of 36 nm, and impressive external quantum efficiencies (EQEs) of 7.39% and 7.18%, respectively. Owing to the “spread-open” conformation and weak π–π packing interactions in 3,6PC9N, its nondoped device exhibits a higher EQE of 4.17%, and color coordinates of (0.162, 0.035). This work offers an effective approach to high-performance UV emitters featuring short-wavelength narrowband electroluminescence.

Oxide-based all-solid-state batteries (ASSBs) offer high safety and chemical stability but suffer from large interfacial charge transfer resistance (R_CT) between electrodes and solid electrolytes (SEs). This study introduces a 24 GHz millimeter-wave (MMW) irradiation technique for interface engineering that densifies SEs while suppressing interdiffusion. MMW irradiation promotes uniform microstructure formation, inhibits the growth of resistive interphases such as La₂Li_0.5Co_0.5O₄, and markedly improves electrochemical performance. The R_CT decreases by more than 1 order of magnitude compared to conventional sintering. Diffusion coefficient analysis revealed that the La³⁺ diffusion was significantly suppressed under MMW irradiation compared to conventional sintering. This behavior arises from the lower ponderomotive force acting on La³⁺ due to its smaller z²/m value. The MMW-assisted sintering strategy provides a thermally nonequilibrium pathway to achieve simultaneous SE densification and sustained interfacial Li-ion transport activity in oxide-based ASSBs.