Nano Materials Science最新文献

High-performance flexible pressure sensors provide comprehensive tactile perception and are applied in human activity monitoring, soft robotics, medical treatment, and human-computer interface. However, these flexible pressure sensors require extensive nano-architectural design and complicated manufacturing and are time-consuming. Herein, a highly sensitive, flexible piezoresistive tactile sensor is designed and fabricated, consisting of three main parts: the randomly distributed microstructure on T-ZnOw/PDMS film as a top substrate, multilayer Ti₃C₂-MXene film as an intermediate conductive filler, and the few-layer Ti₃C₂-MXene nanosheet-based interdigital electrodes as the bottom substrate. The MXene-based piezoresistive sensor with randomly distributed microstructure exhibits a high sensitivity over a broad pressure range (less than 10 ​kPa for 175 ​kPa⁻¹) and possesses an out-standing permanence of up to 5000 cycles. Moreover, a 16-pixel sensor array is designed, and its potential applications in visualizing pressure distribution and an example of tactile feedback are demonstrated. This fully sprayed MXene-based pressure sensor, with high sensitivity and excellent durability, can be widely used in, electronic skin, intelligent robots, and many other emerging technologies.

Recently, poly(ethylene oxide) (PEO)-based solid polymer electrolytes have been attracting great attention, and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performance all-solid-state lithium metal batteries. In this article, a novel sandwich structured solid-state PEO composite electrolyte is developed for high performance all-solid-state lithium metal batteries. The PEO-based composite electrolyte is fabricated by hot-pressing PEO, LiTFSI and Ti₃C₂T_x MXene nanosheets into glass fiber cloth (GFC). The as-prepared GFC@PEO-MXene electrolyte shows high mechanical properties, good electrochemical stability, and high lithium-ion migration number, which indicates an obvious synergistic effect from the microscale GFC and the nanoscale MXene. Such as, the GFC@PEO-1 wt% MXene electrolyte shows a high tensile strength of 43.43 ​MPa and an impressive Young's modulus of 496 ​MPa, which are increased by 1205% and 6048% over those of PEO. Meanwhile, the ionic conductivity of GFC@PEO-1 wt% MXene at 60 ​°C reaches 5.01 ​× ​10⁻² ​S ​m⁻¹, which is increased by around 200% compared with that of GFC@PEO electrolyte. In addition, the Li/Li symmetric battery based on GFC@PEO-1 wt% MXene electrolyte shows an excellent cycling stability over 800 ​h (0.3 ​mA ​cm⁻², 0.3 ​mAh cm⁻²), which is obviously longer than that based on PEO and GFC@PEO electrolytes due to the better compatibility of GFC@PEO-1 wt% MXene electrolyte with Li anode. Furthermore, the solid-state Li/LiFePO₄ battery with GFC@PEO-1 wt% MXene as electrolyte demonstrates a high capacity of 110.2–166.1 ​mAh g⁻¹ in a wide temperature range of 25–60 ​°C, and an excellent capacity retention rate. The developed sandwich structured GFC@PEO-1 wt% MXene electrolyte with the excellent overall performance is promising for next generation high performance all-solid-state lithium metal batteries.

This work presents the development of hierarchical niobium pentoxide (Nb₂O₅)-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue (MB) pollutants from aqueous solutions. The Nb₂O₅ nanorods were vertically grown using a hydrothermal process on a base electrospun nanofibrous membrane made of polyacrylonitrile/polyvinylidene fluoride/ammonium niobate (V) oxalate hydrate (Nb₂O₅@PAN/PVDF/ANO). They were characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) analysis, and Fourier transform infrared (FTIR) spectroscopy. These composite nanofibers possessed a narrow optical bandgap energy of 3.31 ​eV and demonstrated an MB degradation efficiency of 96 ​% after 480 ​min contact time. The pseudo-first-order kinetic study was also conducted, in which Nb₂O₅@PAN/PVDF/ANO nanofibers have kinetic constant values of 1.29 ​× ​10⁻² ​min⁻¹ and 0.30 ​× ​10⁻² ​min⁻¹ for adsorption and photocatalytic degradation of MB aqueous solutions, respectively. These values are 17.7 and 7.8 times greater than those of PAN/PVDF/ANO nanofibers without Nb₂O₅ nanostructures. Besides their outstanding photocatalytic performance, the developed membrane materials exhibit advantageous characteristics in recycling, which subsequently widen their practical use in environmental remediation applications.

Nanorubber/epoxy composites containing 0, 2, 6 and 10 ​wt% nanorubber are subjected to uniaxial compression over a wide range of strain rate from 8 ​× ​10⁻⁴ s⁻¹ to ∼2 ​× ​10⁴ s⁻¹. Unexpectedly, their strain rate sensitivity and strain hardening index increase with increasing nanorubber content. Potential mechanisms are proposed based on numerical simulations using a unit cell model. An increase in the strain rate sensitivity with increasing nanorubber content results from the fact that the nanorubber becomes less incompressible at high strain, generating a higher hydro-static pressure. Adiabatic shear localization starts to occur in the epoxy under a strain rate of 22,000 s⁻¹ when the strain exceeds 0.35. The presence of nanorubber in the epoxy reduces adiabatic shear localization by preventing it from propagating.

Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence. The memristor is an ideal artificial synaptic device with fast operation and good tolerance. Here, we have prepared a memristor device with Au/CsPbBr₃/ITO structure. The memristor device exhibits resistance switching behavior, the high and low resistance states no obvious decline after 400 switching times. The memristor device is stimulated by voltage pulses to simulate biological synaptic plasticity, such as long-term potentiation, long-term depression, pair-pulse facilitation, short-term depression, and short-term potentiation. The transformation from short-term memory to long-term memory is achieved by changing the stimulation frequency. In addition, a convolutional neural network was constructed to train/recognize MNIST handwritten data sets; a distinguished recognition accuracy of ∼96.7% on the digital image was obtained in 100 epochs, which is more accurate than other memristor-based neural networks. These results show that the memristor device based on CsPbBr₃ has immense potential in the neuromorphic computing system.

Solar steam generation (SSG) is widely regarded as one of the most sustainable technologies for seawater desalination. However, salt fouling severely compromises the evaporation performance and lifetime of evaporators, limiting their practical applications. Herein, we propose a hierarchical salt-rejection (HSR) strategy to prevent salt precipitation during long-term evaporation while maintaining a rapid evaporation rate, even in high-salinity brine. The salt diffusion process is segmented into three steps—insulation, branching diffusion, and arterial transport—that significantly enhance the salt-resistance properties of the evaporator. Moreover, the HSR strategy overcomes the tradeoff between salt resistance and evaporation rate. Consequently, a high evaporation rate of 2.84 ​kg ​m⁻² ​h⁻¹, stable evaporation for 7 days cyclic tests in 20 ​wt% NaCl solution, and continuous operation for 170 ​h in natural seawater under 1 sun illumination were achieved. Compared with control evaporators, the HSR evaporator exhibited a >54% enhancement in total water evaporation mass during 24 ​h continuous evaporation in 20 ​wt% salt water. Furthermore, a water collection device equipped with the HSR evaporator realized a high water purification rate (1.1 ​kg ​m⁻² ​h⁻¹), highlighting its potential for agricultural applications.