Materials Advances最新文献

Copper nanowires (CuNWs), featuring anisotropic highly conductive crystalline facets, represent an ideal nanostructure to fabricate on-demand materials as transparent electrodes and efficient electrocatalysts. The development of reliable and robust CuNWs requires achieving a full control over their synthesis and morphology growth, a challenge that continues to puzzle materials scientists. In this study, we systematically investigated the correlation between the critical synthetic parameters and the structural properties of nanowires using a design of experiments (DOE) approach. Multiparametric variation of experimental reaction conditions combined with orthogonal technical analysis allowed us to develop a sound predictive model that provides guidelines for designing CuNWs with controlled morphology and reaction yield. Beyond these synthetic achievements, voltammetric and electrocatalytic experiments were used to correlate the CuNWs morphology and structure to their catalytic activity and selectivity toward CO₂ electroreduction, thus opening new avenues for further intersectoral actions.

In order to improve the specific capacity of intercalation electrodes for sodium-ion batteries, it is necessary to identify materials capable of storing Na⁺ ions by activating multi-electron redox reactions. Herein, we report a NaFeVPO₄(SO₄)₂ compound as a multi-electron electrode that combines the most abundant Fe and V ions, having multiple oxidation states, with a stable mixed phosphate–sulfate matrix. Na_xFeVPO₄(SO₄)₂ reversibly intercalates a total of 3 moles of Na⁺ ions (corresponding to a specific capacity of 175 mA h g⁻¹) within a potential range of 1.5–4.2 V, which is concomitant with a limited variation in the lattice volume (up to 5.2%). NaFeVPO₄(SO₄)₂ interacts with rGO, resulting in rGO covering the phosphate–sulphate particles, and the thickness of the covering varies between 5 and 10 nm. The NaFeVPO₄(SO₄)₂/rGO composite stores Na⁺ ions via a hybrid mechanism involving faradaic and capacitive reactions. In sodium half-cells, the NaFeVPO₄(SO₄)₂/rGO composite displays high capacity (about 90 mA h g⁻¹), and it exhibits an excellent long-term cycling stability at elevated temperatures (about 96–97% after 100 cycles at 20 °C, followed by the next 100 cycles at 40 °C). The improved electrochemical performance is discussed based on the structural robustness of NaFeVPO₄(SO₄)₂ and the surface interaction of NaFeVPO₄(SO₄)₂/rGO with an electrolyte salt and electrolyte solvent. The information from this study will be relevant to the design of high energy polyanionic electrodes for practical application in sodium-ion batteries.

Plasmonic silver-decorated TiO₂ inverse opal has shown an interesting potential for photocatalysis owing to its physically tunable optical absorbance, highly active area, and flexible fabrication. In this study, electrophoretic deposition was used as a key technique to overcome the disadvantages of traditional inverse opal (IO)-fabricating methods, resulting in high reproducibility, chemical stability, and periodic area. The use of IO structural engineering, beneficially delocalizing and enhancing absorbed visible light, accounted for 46% of the total solar light, leading to the enhancement of the localized surface plasmonic resonance (LSPR) hot electrons of Ag NPs and an enhanced local electromagnetic (EM) field for the formation of photogenerated electrons on TiO₂. These enhancements in Ag-deposited TiO₂ IO promoted the excellent photocatalytic kinetic constant of methylene blue degradation around 17 × 10⁻³ min⁻¹, responding to tunable optical absorption at the stopband edge of TiO₂ IO containing 288-nm sized pores and low absorbance of Ag in the overlapped band. The explanation for the enhanced photocatalytic mechanism was studied based on high Ag deposition density, decrease in photocurrent, increase in electron lifetime in electrolytes, and the contribution of a slow photon effect to these characteristics. The proposed photocatalysis mechanism concerned the enhancement of EM-generated electrons on TiO₂ that immigrate to the Ag surface for photoreduction while photooxidation occurred at the TiO₂ surface by the holes. This study provides an interesting strategy to improve the photocatalysis of semiconductor–metal composite systems.

The development of Li metal batteries with increased lifespan and energy density is crucial for next-generation energy storage systems. To achieve this, it is necessary to control the growth of Li dendrites, which can lead to cycling performance issues and safety concerns. One approach to increase the energy density of large-scale Li metal-based batteries is to use thin Li metal anodes. However, fabricating thin Li metal anodes from natural oxide layers can be difficult. In this study, we used pure Li metal powder to fabricate thin Li metal anodes, which do not possess a natural oxide layer. This resulted in Li plating with a low overpotential on the unprotected Li metal surface. Our fabricated LiMP symmetric cell maintained stable cycling for over 170 hours at a current density of 1.0 mA cm⁻², demonstrating superior performance compared to bare Li metal foil. Furthermore, we evaluated the performance of an all-solid-state battery (ASSB) using a polymer solid electrolyte and an oxide-based solid electrolyte in the fabricated LiMP symmetric cell. At 0.1 mA cm⁻², the conventional Li symmetric cell experienced polarization after 200 hours, while the LiMP symmetric cell remained stable even after 600 hours. Taken together, these results provide new insights into the development of high-performance Li metal batteries.

Agricultural health is one of the most important aspects of improving crop productivity, which can significantly decrease the demand for food. Plant diseases and nutritional value are among the crucial factors affecting food safety and quality, subsequently reducing the yield of the crops and increasing plant mortality. Therefore, continuous monitoring of plant health is of utmost importance to enhance the yield of crops. In this aspect, microneedle (MN)-based sensing technology is potentially able to monitor agricultural health. Borrowing a page from medicine, minimally invasive MNs have been effectively used to deliver drugs and biomolecules within the human body without any pain or tissue damage. Usually, MNs have been divided by researchers into four groups: solid microneedles (S-MNs), hollow microneedles (H-MNs), dissolving microneedles (D-MNs), and coated microneedles (C-MNs), which are effectively used according to requirements of delivery of biomolecules and sensing applications. The MN-based probe is directly attached to the relevant part of the plant tissue, thereby bypassing the cuticles. Interestingly, MN-based sensing technology offers newer insight into agriculture health by continuously monitoring plant health, including nutritional values and pathogens. This article opens newer avenues and provides knowledge about the fabrication of MN-based sensing technology for plant health that might benefit the food and agricultural industry.

The photodegradation process of pyrene–(CH₂)₁₂–O–(CH₂)₂-N,N-dimethylaniline (Py-DMA), serving as a model molecular system for exciplex-forming A–D systems, is meticulously examined in solution. The alkyl chain-linker ensures efficient electron transfer between Py and DMA, enabling exciplex formation at concentrations as low as ∼5 μM, free from the interferences dominant in solid-state devices (domain–electrode interface, domain morphological change, accumulation of defects, and so on). The photodegradation mechanism of Py-DMA is proposed for the first time based on chemical identification using steady-state spectroscopy and LC-UV-MS techniques. The mechanism predicts Py-MMA (N-monomethylaniline) and Py-MFA (N-methylformanilide) as primary products and is verified by crosschecking experimental data from FT-IR and ¹H NMR, as well as quantum mechanical calculation data. The heavy involvement of molecular oxygen (O₂) predicted in the mechanism is confirmed by a series of deoxygenated condition experiments. Although we focus on the two primary photodegradation products, secondary, tertiary, and subsequent photodegradation products are also reported, such as PyOH-MPCA (methylphenylcarbamic acid), Py-FA (formanilide), and even unspecified black carbon precipitates. With recent emerging evidence of a close correlation between the stabilities of optoelectronic devices and their active molecules, the molecular photodegradation pathways of Py-DMA will shed light on the molecular design for exciplex-based optoelectronic devices with longer lifespans.

Efficient synthesis of extended π-conjugated systems containing sulphur-rich aromatics is of special interest for organic electronics. Herein, we report the synthesis of new π-conjugated 5,5′-diphenyl-2,2′-bithiophene-based tricatenars. The materials have the same aromatic backbone ending at one terminus with a 3,5-diheptyloxy substituted-benzene ring and a single hexyloxy chain at the other end. They differ from each other in the halogen substitution pattern used at the single alkylated end, where fluorine at different positions was used. The fluorine atom was also replaced by chlorine or bromine atoms to investigate the effect of different types of halogen substituents on the phase behaviour. The molecular self-assembly of the materials was investigated using differential scanning calorimetry, polarized optical microscopy, X-ray diffraction and fluorescence techniques. Depending on the type and position of the halogen substituent, different types of mesophases were observed, including nematic, smectic, and chiral isotropic liquid phase (Iso₁^[*^]) and achiral double-gyroid bicontinuous cubic phases with a double helical network structure and Iad symmetry. In particular, the steric effect of halogen substituents adapts two different molecular packing for the cubic phase with local helicity and short-range order, respectively. All materials are fluorescent active, and their fluorescence behaviour could be altered by the type and position of the halogen substituent. Thus, this report provides new functional materials, which could be of interest for optoelectronic applications.

Anhydrous and hydrated UF₄ microrods (5–25 μm) were prepared from the reactions of UO₂ microrods (5–15 μm) with HF(g), produced from the decomposition of silver bifluoride (AgHF₂, SBF). In order to optimize the preparation of UF₄ mr, several experimental parameters including atmosphere (air or N₂), temperature (150 or 250 °C) and amount of SBF were evaluated. In all reactions, rodlike morphologies were retained. At 250 °C, the reaction products always consist of an anhydrous UF₄/hydrated UF₄ mixture, while at 150 °C only hydrated UF₄ was detected. Anhydrous UF₄ microrods were obtained by dehydration of the anhydrous UF₄/hydated UF₄ mixture using TGA-DSC. Changing the atmosphere from air to N₂ or reducing the amount of SBF by half did not affect the nature of the reaction products.

This comprehensive review delves into the critical relationship between process, structure, and properties in the context of manufacturing neodymium (NdFeB) permanent magnets using laser powder bed fusion (LPBF) technology. The article systematically explores how LPBF process parameters influence microstructural characteristics and, in turn, affect the magnetic performance of NdFeB magnets. Key areas of focus include the optimization of processing techniques, the selection and characteristics of material feedstock, and the microstructural features that are crucial to achieving desired magnetic properties. The review emphasizes how specific variations in LPBF processing can result in microstructures that either enhance or impair magnetic performance, providing valuable insights into the development of more efficient manufacturing strategies.

Merocyanines are polar organic π-conjugated molecules consisting of electronic donor (D) and acceptor (A) subunits connected via a conjugated bridge. They have been investigated because of their unique self-assembly and optoelectronic properties, making them ideal active materials for organic electronic applications. The understanding of their charge transport properties at the nanoscale is very challenging and mostly an unexplored field. We report a theoretical study on modelling the hole transport parameters and mobility, together with the investigation of the structure–property relationships of seven merocyanine single crystals, consisting of different combinations of D–A units. We critically discuss the impact of both static (energetic) and dynamic (thermal) disorder effects on charge mobility and transport networks, by emphasizing the importance of including such contributions for an in-depth understanding of the charge transport properties of polar organic semiconductors.