Frontiers of Materials Science最新文献

The demand for low-temperature cured conductive silver pastes increases rapidly due to the development of advanced electronic fields, such as flexible electronics. Lowering curing temperatures of conductive silver pastes is generally realized using low-boiling-point solvents. However, such solvents have a low viscosity, leading to the sedimentation of the conductive phase. Increasing the content of the highly viscous binder phase helps solve this issue, but it will lower the electric conductivity. Herein, the trade-off between curing temperature and conductivity of conductive silver pastes was overcome by applying nano-silver particles as the sedimentation inhibitor while bifunctional epoxidized cardol (E-Cardol), with flexible C₁₅ side chains that can significantly enhance the toughness, as the binder. Experiments were performed to determine chemical compositions, reveal morphologies, and measure conductive resistivity values. Conductive silver pastes with a curing temperature of 140 °C and a silver content of 65 wt.% were fabricated, exhibiting a resistivity of 3.10 × 10⁻⁵ Ω·cm, comparable to that of conventional low-temperature cured silver pastes with the silver content of 80 wt.%. Moreover, this silver paste also exhibited excellent adhesion performance and enhanced anti-folding property.

A novel bifunctional electrocatalyst for water splitting was constructed with the CoSe/MoSe₂ heterojunction encapsulated within a nitrogen-doped carbon matrix (Co₁Mo₂Se/Co-N-C). This catalyst was synthesized via a facile one-step high-temperature calcination process. By optimizing the molar ratio of n(Co)/n(Mo) and the calcination temperature, a unique architecture was achieved featuring uniformly dispersed nanoparticles, well-defined heterointerfaces, and isolated Co atoms embedded in the carbon layer. Such structural features facilitated efficient transfer of electrons and maximized exposure of active sites. Electrochemical evaluations in 1.0 mol·L⁻¹ KOH demonstrated that Co₁Mo₂Se/Co-N-C exhibited excellent hydrogen evolution reaction performance, requiring an overpotential of only 63 mV to reach 10 mA·cm⁻² with a Tafel slope of 60 mV·dec⁻¹, comparable to that of commercial Pt/C. For oxygen evolution reaction, the catalyst achieved an overpotential of 328 mV at 10 mA·cm⁻² and a Tafel slope of 97 mV·dec⁻¹. Furthermore, a full water splitting cell based on this catalyst reached 10 mA·cm⁻² at an applied voltage of 1.623 V. These results highlight synergistic effects of the heterojunction and the nitrogen-doped carbon matrix, offering a promising strategy for the sustainable hydrogen production.

Traditional surface modification methods such as physical or chemical vapor deposition and impregnation have been widely used to modify perovskite surfaces. However, there is weak interaction between metal nanoparticles (NPs) loaded via these methods and the perovskite oxide support, which may lead to issues such as deactivation during application owing to poor stability, easy agglomeration, and carbon deposition. Exsolution refers to the in-situ growth of NPs on the surface of parent oxides. The presence of NPs increases the number of active sites for the reaction, and NPs exhibit strong interaction with the matrix, showing excellent catalytic performance and high stability. Therefore, in recent years, the field of in-situ exsolution has received extensive attention. Based on this, this paper starts from exsolution phenomena of perovskite oxides, reviews existing exsolution methods, sorts out structurally regulated exsolution strategies of perovskite oxides in terms of A-site defects, B-site cation dopants, and phase transformation, introduces application fields of the in-situ exsolution, and provides prospect.

Conventional hydrogels exhibit good performance in various biomedical applications. They consist of a three-dimensional network with porous structures that are constructed from synthetic or natural polymers through physical or chemical cross-linking. However, a critical challenge lies in their vulnerability to mechanical damage, as conventional hydrogels often fail to maintain structural integrity under minor trauma. In response to this issue, self-healing hydrogels can autonomously repair themselves after damage, restoring their original functionality without needing external intervention. This remarkable capability significantly extends the lifespan of critical products, including wound dressings, biosensors, drug delivery and tissue engineering scaffolds. This review summarizes the synthesis mechanisms while emphasizing the latest application research advancements. By highlighting the distinct benefits of self-healing hydrogels, we systematically review recent progress in synthesis methods. Our goal is to provide valuable insights that will help researchers in designing and developing more efficient self-healing hydrogels, paving the way for enhanced biomedical solutions.

Titanium (Ti)/steel clad plates, combining corrosion resistance of titanium with high strength of steel, are critical for applications in petroleum, aerospace, and pressure vessels. This paper comprehensively reviews four manufacturing methods: explosive bonding, roll bonding, explosive-roll bonding, and diffusion bonding detailing their advantages, limitations, and mechanisms. Explosive bonding forms a wavy interface with high strength but faces challenges in process control. Roll bonding ensures dimensional precision but suffers from weakened interfaces due to brittle intermetallic compounds (IMCs). Explosive-roll bonding balances efficiency and quality, yet risks IMCs regrowth during reheating. Diffusion bonding minimizes deformation but requires prolonged processing. Analysis of elemental diffusion and compound formation reveals that coexisting TiC and Fe–Ti IMCs degrade interfacial strength, while interlayers effectively suppress brittle phases. Experimental results highlight that rolling temperatures and interlayer selection critically influence shear strength and tensile properties. The corrugated-flat rolling (CFR) technique enhances mechanical interlocking and diffusion, achieving superior interface bonding strength. Future research should prioritize optimizing process parameters to control IMCs, developing eco-friendly methods, and revealing dynamic interface evolution to research high-performance and large-scale titanium/steel clad plates.

Based on the simulation of three key biological features related to dolphin skin, namely the subcutaneous papilla structure, the natural hydrogel collagen in papilla space, and the metabolic renewal function of the mucus layer, we designed a dolphin skin-inspired hydrogel fiber-based drag-reducing slippery coating (DIHSC) for marine antifouling. It was revealed that water-absorbing fibers could form hydrogel films on the surface of DIHSC after absorbing water and swelling. The increase in the coverage degree of water-absorbing fibers caused by the enhancement in the implantation density led to the reduction in the frictional resistance of the hydrogel film, making the surface much smoother. Static immersion and dynamic scouring experiments showed that fibers had stable fixation, while the experiment on marine microalgae indicated that DIHSC had excellent marine antifouling performance. We successfully obtained a smooth drag-reducing hydrogel surface by implanting water-absorbing fibers using the electrostatic injection technology, which effectively imitated the smoothness and low frictional resistance of the dolphin surface and metabolic renewal behaviors of the mucus layer, realizing long-term marine antifouling performance. This study promotes the application of bionic hydrogels in marine antifouling aspects.

A molybdenum (Mo)-modified LaFeO₃ (LFMO) perovskite catalyst was synthesized to activate peroxymonosulfate (PMS) for the degradation of indole in solution. The catalyst was characterized by XRD, SEM, and XPS. Results indicate that LFMO possesses a higher specific surface area and more catalytic active sites compared to unmodified LaFeO₃. XPS analysis reveals that the activation of PMS is mediated by Fe²⁺/Fe³⁺ and Mo⁴⁺/Mo⁶⁺ reduction–oxidation cycles. Oxygen vacancies generated by molybdenum substitution serve as reaction sites, which accelerate the dissociation of PMS and the production of reactive oxygen species. Chemical quenching experiments and EPR spectroscopic analyses were employed to elucidate the mechanism, highlighting the significant role of non-radical species in the removal of indole. Under optimal reaction conditions, the degradation efficiency of indole reached 90.53% within 30 min, demonstrating strong anti-interference against inorganic anions and natural organic matter. LFMO particles exhibit sustained catalytic activity and stability over five consecutive cycles. This LFMO/PMS system provides valuable insights for the development of non-radical degradation pathways based on PMS.

Metal-organic frameworks (MOFs) and hydrogels have abundant pores, creating much potential for applications in water purification, organic dye adsorption, and so on. In this study, polyvinyl alcohol (PVA) or PVA/chitosan (CS) hydrogel tubes containing in-situ synthesized MOF particles were facilely synthesized, which are capable of removing dyes from flowing fluids. The state of polymer chains during synthesis has a significant impact on microstructures and properties of obtained MOF/hydrogel composites. Hierarchical pores and polar groups endow such devices with good adsorption performance. Besides, a tubular MOF/hydrogel device was found to display excellent flexibility and stability, in which brittle ZIF-8 particles were surrounded and protected by the soft hydrogel matrix effectively. This work supplies a facile and novel strategy to prepare soft MOF/hydrogel tubes for adsorption of pollutants as well as for other potential applications.

Heavy metal ion (HMI) contamination threatens the environment’s integrity and human health, indicating the critical need for sensitive and reliable detection methods. The present review critically discusses the most recent flexible and rigid sensor technologies for the detection of HMIs. Flexible sensors are heterogeneous in the following types: adaptability to different shapes, various environments, and real-time monitoring, which make them uniquely appropriate for applications in wearable devices, biomedical applications, and environmental monitoring systems. The non-flexible sensors perform well with great accuracy and sensitivity, especially in laboratory and industrial environments. Recent advances are focused on materials design, fabrication methodologies, and signal processing algorithms, which significantly improve sensor performance and help deploy sensors in complex real-world scenarios. Still, there are drawbacks to the need for more sensitivity, selectivity, durability, and scalability in developing sensors. Future directions for research should involve improvement in the design of materials to use multimodal sensing techniques and develop further miniaturizations and energy efficiency, as well as development of intelligent sensor networks and collaborative work in cross-disciplinary fields. This review can be an essential reference for the scientific and engineering communities focused on developing and applying flexible and non-flexible sensors to detect HMIs.

Tetra-aminophenyl porphyrin (TAPP)-grafted Zn–Ag–In–S quantum dots (ZAIS QDs)/poly(maleic anhydride-alt-1-octadecene) (PMAO) nanoparticles were synthesized and their photoluminescence properties as well as photodynamic properties were studied. ZAIS QDs showed the brightest photoluminescence and highest quantum yield at an optimized Zn feeding molar ratio of 20%. Those TAPP-grafted nanoparticles (i.e., ZAIS/PMAO-g-TAPP) were able to produce ¹O₂ in aqueous solution under light irradiation as indicated by the ¹O₂ indicator, 9,10-anthracenediyl-bis(methylene) dimalonic acid (ADMA). ZAIS/PMAO-g-TAPP nanoparticles also demonstrate good biocompatibility and low dark toxicity even at a concentration as high as 2.8 mg·mL⁻¹, whith can be applied as both a fluorescence probe and a photodynamic therapy (PDT) agent. The PDT treatment showed that the viability of melanoma A2058 cells was less than 10% after treatment with the 420 nm light irradiation for 15 min at a photosensitizer concentration of 1.7 mg·mL⁻¹. During the PDT treatment with Escherichia coli, the survival rate of the bacteria decreased by −95% after light irradiation at the same concentration. Such dual-functional ZAIS/PMAO-g-TAPP nanoparticles researched in this study demonstrate promising potential for fluorescence labeling as well as effective PDT treatment against cancer cells and bacteria.