Materials Horizons最新文献

As a key building block of mammalian tissues, extracellular matrices (ECMs) stiffen under shear deformation and undergo cell-imparted healing after damage, features that regulate cell fate, communication, and survival. The shear-stiffening behavior is attributed to semi-flexible biopolymeric ECM networks. Inspired by the mechanical behavior of ECMs, we develop acellular nanocomposite living hydrogels (LivGels), comprising network-forming biopolymers and anisotropic hairy nanoparticle linkers that mimic the dynamic mechanical properties of living counterparts. We show that a bifunctional dynamic linker nanoparticle (nLinker), bearing semi-flexible aldehyde- and carboxylate-modified cellulose chains attached to rigid cellulose nanocrystals converts bulk hydrogels to ECM-like analogues via ionic and dynamic covalent hydrazone bonds. The nLinker not only enables the manipulation of nonlinear mechanics and stiffness within the biological window, but also imparts self-healing to the LivGels. This work is a step forward in designing living acellular soft materials with complex dynamic properties using bio-based nanotechnology.

In this study, a new emission gain layer for perovskite light-emitting diodes (PeLEDs) is presented to improve their performance. The emission gain layer consisting of absorption-stable silver nanoparticles is prepared using the post-addition method of the polycaprolactone capping agent (PCL@AgNPs-P). This layer (PCL@AgNPs-P) effectively improves the Förster resonance energy transfer (FRET) between the low-n (minor) and high-n (major) phases in a quasi2D perovskite system, thereby increasing the major emission intensity and efficiency. Moreover, this layer also enhances the Purcell effect, thus increasing the spontaneous emission rates and amplifying the electroluminescence. These combined advantages enable the derived PeLED to achieve higher luminance, external quantum efficiency (EQE), and sustained emission purity. As a result, the optimized PeLED with the PCL@AgNPs-P emission gain layer delivers a maximum luminance of 11 320 cd m^-2 and an EQE of 15.5%, and maintains high green wavelength emission purity and a narrow emission half-maximum width at various operating currents. Our results not only provide a robust pathway for the development of high-performance PeLEDs, but also open up the possibilities of applying PeLEDs in laser optics, where enhanced efficiency and emission characteristics are crucial for creating efficient and high-emission laser sources.

Here, we present for the first time an efficient platform for simultaneous H₂ generation and CO₂ conversion into HCOOH, utilizing a Cu-incorporated NH₂-MIL-125(Ti) material with triethanolamine as the sacrificial agent. When subjected to light, Cu-NH₂-MIL-125(Ti) exhibits a remarkable enhancement in H₂ generation, with a 30-fold increase under UV-Vis light and an 8-fold increase under visible irradiation compared to the pristine MOF. The study on the CO₂ photoreduction ability of Cu-NH₂-MIL-125(Ti) indicated successful conversion into formic acid yielding 62.4 μmol g_cat^-1 under visible irradiation. This notable improvement in photocatalytic activity can be attributed to the heightened light absorption capacity and efficient charge transportation and separation mechanisms inherent in Cu-NH₂-MIL-125(Ti). Furthermore, the stability of the Cu-NH₂-MIL-125(Ti) photocatalyst remains steady even after 24 hours of continuous irradiation. The theoretical simulations suggest that Cu introduction effectively reduces the bandgap while leaving the position and composition of the valence band unaffected.

In this study, nonvolatile bipolar resistive switching and synaptic emulation behaviors are performed in an InGaP quantum dots (QDs)/HfO₂-based memristor device. First, the physical and chemical properties of InGaP QDs are investigated by high-resolution transmission electron microscopy and spectrophotometric analysis. Through comparative experiments, it is proven that the HfO₂ layer improves the variations in resistive switching characteristics. Additionally, the Al/QDs/HfO₂/ITO device exhibits reversible switching performances with excellent data retention. Fast switching speeds in the order of nanoseconds were confirmed, which could be explained by trapping/detrapping and quantum tunneling effects by the trap provided by nanoscale InGaP QDs. In addition, the operating voltage is decreased when the device is exposed to ultraviolet light for low-power switching. Biological synapse features such as spike-timing-dependent plasticity are emulated for neuromorphic systems. Finally, the incremental step pulse using proven algorithm method enabled the implementation of four-bit states (16 states), markedly enhancing the inference precision of neuromorphic systems.

Polymer-embedded metal nanoparticles are in great demand owing to their unique features, leading to their use in various important applications, including catalysis reactions. However, particle sintering and aggregation are serious drawbacks, resulting in a drastic loss of catalytic activity and recyclability. Herein, a reduction-immobilizing strategy of polymer-embedded sub-2 nm Cu nanoparticles offered highly controlled distribution and nanoparticle size within polymer structures with high fidelity. This work sheds light on the high catalytic performance of nanoparticles that rely on their ultrasmall size and uniform distribution in polymer structures, generating more active sites that result in high efficiency reduction of organic compounds. A catalysis study was carried out for the hydrogenation of nitro compounds, achieving nearly 100% reduction in an extremely short time and remaining stable after 15 consecutive cycles. Furthermore, the catalytic mechanism was demonstrated by density functional theory (DFT) calculations. Notably, the discovery of this facile strategy may enable the remarkable cutting-edge design of catalyst materials with promising performance and stability.

Extracting hydrogen from metallic components can open up a new pathway for preventing hydrogen embrittlement. To this end, we propose an electrochemically driven, all-solid method for hydrogen control, capable of both extracting and storing hydrogen simultaneously. In this approach, we employ acid-in-clay as a proton conducting electrolyte at room temperature. Through this electrochemical treatment, hydrogen is efficiently extracted from pre-charged steels, thereby restoring their tensile properties and preventing embrittlement. Moreover, it has been confirmed that the extracted hydrogen can be efficiently collected at the counter electrode, demonstrating the significant advantages of the process.

Growing energy demands make cost-effective, high-performance perovskite solar cells (PSCs) desirable. However, their commercial applications are limited due to defect formation and instability. Passivation technologies help enhance their favorable traits. Herein, we propose a pioneering technique utilizing non-thermal plasma (NTP) synthesis for passivating inherent defects and optimizing the energy levels of perovskites. AC-NTP utilizes ionic charges and uniform electric fields to effectively neutralize defect-induced charge traps, acting as a field-effect passivator. This approach not only mitigates energetic defects, but also facilitates the transformation of NH₄PbI₃ into a CH₃NH₃PbI₃ perovskite through a self-degassing mechanism. The perovskites synthesized using this method demonstrate notable advancements in their properties, as evidenced by X-ray diffraction, UV-vis spectroscopy, and scanning electron microscopy. These improvements include enhanced crystalline quality, superior optical characteristics, and precise nanoparticle size control, with an average size of 54 nm. In situ Rietveld refinement analysis reveals minimal PbI₂ formation, resulting in fewer lead iodide inversion defects. Accordingly, the PSC fabricated by AC-NTP shows a PCE of 15.25%, significantly higher than that fabricated by the DC one (13.29%), which demonstrates improved stability under ambient conditions for over 160 hours. Hysteresis assessment, SCLC analysis, and Shockley diode modeling show our PSCs' low defect densities and high interface quality. Moreover, DFT was applied to indirectly analyze the effects of NTP on the perovskites, focusing on quantum confinement effects and lattice arrangement's influence on the optoelectronic characteristics of MAPbI₃ nanoparticles. The findings confirm that NTP synthesis leads to more optimal PSCs, showing notable improvement in photovoltaics.

Sodium-ion batteries have emerged as a promising secondary battery system due to the abundance of sodium resources. One of the boosters for accelerating the practical application of sodium-ion batteries is the innovation in anode materials. This study focuses on developing a high-performance hard carbon anode material derived from hydroxymethylfurfural, produced from carbohydrates, using a straightforward thermal condensation method. The process results in a unique pseudo-graphitic material with abundant microporosity. Electrochemical evaluations demonstrate excellent sodium storage performance by maintaining the plateau capacity even at higher current densities. This translates to a promising energy density when coupled with the cathode material. However, we also discuss the influence of electrolyte composition on the performance of the hydroxymethylfurfural-derived hard carbon, emphasizing the critical role of electrolyte optimization for the development of efficient and sustainable carbonaceous anode materials for next-generation sodium-based batteries.

Hydrogels with abundant water and responsiveness to external stimuli have emerged as promising candidates for artificial muscles and garnered significant interest for applications as soft actuators and robots. However, most hydrogels possess amorphous structures and exhibit slow, isotropic responses to external stimuli. These features are far inferior to real muscles, which have ordered structures and endow living organisms with programmable deformations and motions through fast, anisotropic responses in complex environments. In recent years, this issue has been addressed by a conceptual new strategy to develop muscle-like hydrogels with highly oriented nanosheets. These hydrogels exhibit fast, isochoric responses based on temperature-mediated electrostatic repulsion between charged nanosheets rather than water diffusion, which significantly advances the development of soft actuators and robots. This minireview summarizes the recent progress in muscle-like hydrogels and their applications as soft actuators and robots. We first introduce the synthesis of muscle-like hydrogels with monodomain structures and the unique mechanism for rapid and isochoric deformations. Then, the developments of hydrogels with complex ordered structures and hydrogel-based soft robots are discussed. The morphing mechanisms and motion kinematics of the hydrogel actuators and robots are highlighted. Finally, concluding remarks are given to discuss future opportunities and challenges in this field.

Alzheimer's disease (AD) is a chronic, progressive neurodegenerative disorder marked by permanent impairment of brain function across the whole brain. This condition results in a progressive deterioration of cognitive function in patients and is frequently associated with psychological symptoms such as agitation and anxiety, imposing a significant burden on both patients and their families. Nanomaterials possess numerous distinctive physical and chemical features that render them extensively utilized. In the biomedical domain, nanomaterials can be utilized for disease prevention and therapy, including medication delivery systems, biosensors, and tissue engineering. This article explores the etiology and potential molecular processes of AD, as well as the application of carbon-based nanomaterials in the diagnosis and treatment of AD. Some of such nanomaterials are carbon quantum dots, carbon nanotubes, and graphene, among others. These materials possess distinctive physicochemical features that render them highly promising for applications in biosensing, drug delivery, neuroprotection, and photothermal treatment. In addition, this review explored various therapeutic approaches for AD in terms of reducing inflammation, preventing oxidative damage, and inhibiting Aβ aggregation. The advent of carbon nanomaterials in nanotechnology has facilitated the development of novel treatment approaches for Alzheimer's disease. These strategies provide promising approaches for early diagnosis, effective intervention and neuroprotection of the disease.