Advanced Composites and Hybrid Materials最新文献

Catalysts that effectively degrade organic pollutants and exhibit bactericidal properties are highly up-and-compromising for water treatment applications. To overcome the inherent limitation that the rapid recombination of the photogenerated carriers and to extend the practical utility of Bi₂WO₆, a flower-like structure of 7 wt.% Er³⁺-doped Bi₂WO₆ (Er_7%-Bi₂WO₆) capable of oxygen vacancy and crystal defect was synthesized using a straightforward hydrothermal method. Under visible light irradiation (λ > 420 nm), the Er_7%-Bi₂WO₆ achieved a Rhodamine B (RhB) degradation efficiency of 92% within 80 min, significantly surpassing that of pristine Bi₂WO₆. The kinetic rate constant of Er_7%-Bi₂WO₆ was determined to be 0.0288 min⁻¹, which is 5.9 times higher than the 0.0049 min⁻¹ observed for Bi₂WO₆. Additionally, the bactericidal rate against Escherichia coli after 120 min of visible light exposure was 93.9%, nearly twice that of Bi₂WO₆ at 49.8%. Density functional theory calculations and experimental results confirmed that doping with Er³⁺ introduced lower band gap and more photogenerated carriers, enhanced visible light absorption, and ultimately improved the photocatalytic performance. Electron paramagnetic resonance and radical trapping experiments identified h⁺ and ·O₂⁻ as the primary active species generated during the photocatalytic process of Er_7%-Bi₂WO₆. The RhB removal rate remained above 90% after five degradation cycles, and the treatment efficacy on actual water samples was 76%. This study highlights the potential of Er-doped Bi₂WO₆ to enhance both photocatalytic degradation of organic pollutants and bactericidal performance, thereby expanding the application scope of Bi₂WO₆ in water treatment.

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With the rapid advancement of wearable smart devices, there is an increasing demand for intelligent flexible strain sensors. However, to date, traditional metallic or inorganic semiconductor strain sensors exhibit poor stretchability and sensitivity, limiting their applications in this field. Flexible elastomer-based smart sensing materials (FESSM) offer several advantages, including lightweight design and quantifiable production capabilities. These FESSM have garnered significant attention for their potential applications in robotic electronic skins and intelligent homecare systems. The materials and structural design of FESSM are continually being optimized to facilitate the development of high-performance flexible electronics. This article reviews the latest advancements in the design concepts of materials and structures for FESSM. It examines the preparation methods for various elastic substrates, such as polyurethane fibers and polydimethylsiloxane films, and explores the design of their micro-nano structures, as well as the appropriate use of conductive fillers. This review aims to provide insights and strategies for the design of high-performance FESSM.

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The hot press sintering and heat treatment processes each play a crucial role in influencing the interface between the fibers and the matrix alloy; therefore, this work evaluated the interfacial evolution between carbon fibers and the matrix alloy in SiC_p-C_f/Al composites under sintered and heat-treated conditions. 5SiC_p-5C_f/ZL109 hybrid-reinforced aluminum matrix composites were prepared by hot pressing sintering and T6 heat treatment to investigate their microstructure and properties. The analysis revealed that the SiC_p and C_f were uniformly distributed in the matrix alloy, and after heat treatment, Ni diffused and the Al₃Ni phase on the surface of the carbon fiber transformed into a jagged one. The mechanical interlock between the carbon fiber and the matrix alloy was formed by the jagged Al₃Ni phase, which improved the interface bonding between the carbon fiber and the matrix alloy. The yield strength and the tensile strength of the heat-treated 5SiC_p-5C_f/ZL109 hybrid-reinforced aluminum matrix composites reached 324 MPa and 343 MPa, respectively, 93.3% and 55.5% higher than those of the matrix alloy.

To obtain environment-friendly and renewable hydrogen energy, research is being actively conducted towards lowering the hydrogen evolution reaction (HER) energy barrier through various modifications to the surface of a transition metal bimetal electrochemical catalyst. Herein, we report the development of highly N-doped carbon shell-encapsulated cobalt iron nano cube (CoFe@HNCS) through fine-tuning of the nitrogen-doping content in the carbon shell. The pyridinic N-rich N-doped carbon shell, achieved by adding melamine through electrostatic interactions, improves conductivity, increases active sites, and optimizes Gibbs free energy for hydrogen adsorption. In alkaline HER performance, the optimized CoFe@HNC20 exhibits a lower overpotential (98.2 mV) than CoFe@NCS (133.2 mV) at 10 mA cm⁻². Furthermore, CoFe@HNCS20 as cathode catalyst in anion exchange membrane (AEM) water electrolyzer also shows low cell voltage of 1.808 V to achieve the current density of 0.5 A cm⁻². The expansion of the application to combine solar cells and AEM electrolyzer suggests the possibility of a hydrogen ecosystem.

Hybrid aluminium-carbon fibre-reinforced polymer (Al-CFRP) composites are attracting increasing attention in high-tech aviation and automotive applications, but successfully joining them is challenging due to their differing physiochemical properties, and various surface pretreatments are applied to enhance their interfacial bonding. Herein, we develop a novel method to significantly enhance Al-CFRP bond strength by boehmite crystallisation of aluminium through thickness reinforcement (TTR) pins embedded in the CFRP matrix. The hybrid Al-CFRP joints were prepared using flat aluminium substrates and substrates with 1 mm diameter TTR pins, which were both pretreated with the boehmite crystallisation process and compared to conventional chemical etched, micro blasted, and untreated aluminium control surfaces assembled with CFRP layers in a double cantilever beam configuration for mode I testing. Results reveal that the boehmite crystallisation process can successfully grow a sea of nano needle structures on the flat aluminium surface, which significantly enhances interfacial bonding with the CFRP, leading to increases in fracture toughness of 70%, 250%, and 555% over chemical etched, micro blasted, and untreated control joints, respectively. The addition of aluminium TTR pins provide further reinforcement to the CFRP, and crystallisation of the pins increases the mode I fracture resistance of the Al-CFRP hybrid composite joints by over 1800% compared to joints made with untreated aluminium substrates.

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Surface treatment is essential for enhancing adhesion durability and minimizing substrate damage in hybrid structural materials. This study focuses on developing a hybrid adhesive lap joint by incorporating halloysite nanotube (HNT) with imidazole-functionalized surfaces (IM-HNT) into epoxy adhesives to improve adhesion performance and thermal shock resistance. The surface treatment of HNT with imidazole (IM) introduced a curing catalyst effect, reducing activation energy by 50% and accelerating curing time by 90%, as confirmed by Kissinger’s plot and permittivity measurements. The optimized IM-HNT content improved thermal stability by controlling thermal expansion and enhanced mechanical properties, achieving a 15% increase in tensile strength and a 50% enhancement in fracture toughness. The adhesion performance of steel/carbon fiber-reinforced polymer (CFRP) hybrid joints was evaluated through single-lap shear tests, demonstrating a 25% improvement in shear strength. Adhesion durability was tested under cyclic thermal shock conditions, showing a 30% increase as IM-HNT content increased. Finite element analysis (FEA) revealed reduced residual stress at the adhesive interface, supporting the enhanced thermal and mechanical robustness. This study highlights the potential of surface-treated halloysite nanotubes in hybrid adhesive lap joints to significantly improve adhesion durability and thermal shock resistance, addressing critical requirements for hybrid structural materials.

The advancement of biosensing devices based on field effect transistor (FET) has been rapid, largely due to the simplicity of their operational mechanism, rapid response, ease of miniaturization, and integration. The preparation of field effect transistors using inorganic nanomaterials as channel materials has been extensively employed in biosensing applications, including assessing food quality and safety, environmental monitoring, and diagnosing biological diseases. The detection of disease-causing microorganisms, antibiotics, heavy metals, and harmful gases in modern agricultural breeding environments also necessitates the utilization of sensors that are able to achieving label-free, miniaturized, rapid, and specific detection. Biosensing devices based on field effect transistors are able to rapidly and specifically detect, meeting the needs of modern agricultural breeding environments for low-cost, accurate, miniaturized, and portable devices.

The rise of Internet of Things (IoT) technology has driven a growing demand for the smart gas sensors capable of detecting trace-level hazardous gases with high accuracy, and rapid response at room temperature (RT) is crucial for environment and human health protection. In this study, we report the fabrication of an electrostatic self-assembly-assisted CuO@V₂C MXene-based hybrid van der Waals heterostructure (vdW-HS) coated on a surface acoustic wave (SAW) sensor for ultrasensitive and low-ppb level H₂S detection at RT. The hybrid SAW sensor revealed excellent selectivity, notable sensitivity (~ 39.71 kHz), and faster response/recovery (54/76 s) times to H₂S gas (20 ppm), with low detection limit (~ 27.2 ppb), outperforming its pristine counterparts. Significantly, the hybrid SAW sensor demonstrated superior reversibility, satisfactory long-term stability, and enhanced sensitivity under various elevated temperatures (RT-200 °C) and relative humidity (0 to 80%) conditions. These substantial improvements in H₂S sensing performances of the hybrid SAW sensor can be accredited to the increased surface area, abundant surface terminal groups, defect states, oxygen vacancies, and the Schottky barrier modulation at CuO@V₂C MXene vdW-HS, which collectively enhance the charge transfer and higher H₂S gas adsorption. Furthermore, the density functional theory (DFT) calculations showed that the hybrid composite sensor has a higher adsorption energy for H₂S than pristine sensors, facilitating enhanced H₂S adsorption. The H₂S sensing mechanism is comprehensively elucidated using energy band theory. This study presents a robust framework for cost-effective, high-performance room-temperature smart gas sensors based on hybrid vdW-HS, enabling applications in environmental protection, healthcare and industrial monitoring.

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The incorporation of non-metal dopants can significantly enhance catalytic activity and improve stability. Furthermore, the creation of heterostructures is particularly advantageous to facilitate charge transfer and optimize electronic properties. This study presents an effective bifunctional mixed-valence Ruthenium heterostructure synthesized through a cascading process involving grinding with carbon nitride and subsequent thermal treatment. The catalyst exhibits outstanding electrocatalytic performance with remarkably low overpotentials of 197 mV for the oxygen evolution reaction (OER) and 24.8 mV for the hydrogen evolution reaction (HER), respectively, with the stability exceeding 24 h at a current density of 10 mA cm⁻² in acidic media. Additionally, when employed in an acidic oxygen water splitting (OWS) electrolyzer, the bifunctional catalyst demonstrates excellent activity, achieving an ultralow cell voltage of 1.53 V to sustain 10 mA cm⁻². Enhanced performance is attributed to efficient charge transfer and increased exposure of active sites, providing valuable insights for the development of effective acidic water-electrolysis catalysts for sustainable hydrogen production.

Dosage tolerance is one of the translational challenges of using metformin (Met) in brain therapeutics. This paper presents metal–organic framework (MOF)-74-Mg nanocarriers (NCs) for intranasal (IN) delivery of brain-specific agents with a prolonged release time. We confirmed their excellent biocompatibility (5 mg/mL) and intrinsic fluorescence properties (370/500 nm excitation/emission peak) in Neuro-2A cells. This NC exhibited a high Met loading rate (10% wt/wt) and a sustained and prolonged release pattern of Met (90% release in 16 h) in Dulbecco’s Modified Eagle Medium. We observed an optimal brain accumulation of Met-MOF (9% of the injected dosage) 8 h after IN injection. This percentage is at least 82 times higher than oral administration. Confocal imaging demonstrated significantly higher uptake of Met-MOF, 45 min after IN injection, by 79–85% neurons and 93–97% microglia than astrocytes and oligodendrocytes across 5xFAD mouse brain regions, including hippocampus and striatum. These results suggest MOF-74-Mg is a potential NC for high brain Met accumulation, real-time imaging, and prolonged and sustained release of Met and other neurotherapeutic agents that are challenging to deliver using traditional carriers and administration routes.