Nanomaterials最新文献

Developing free-standing electrodes without the need of metal current collectors, binders, and conductive additives are essential for promoting the development of sodium-ion batteries (SIBs) to attain higher energy density. In this study, we developed and effectively synthesized a novel three-dimensional free-standing sodium-ion battery anode material with the composition of Bi@MoS₂@C carbon nanofibers by cleverly utilizing the energy storage advantages of each material. By growing MoS₂ nanospheres on Bi carbon nanofibers and coating them with a carbon layer, this free-standing system achieves both structural optimization and synergistic performance enhancement. Experimental results show that this composite electrode has a remarkably high initial specific capacity of 275.31 mA h g^-1 at a current density of 0.5 A g^-1, significantly exceeding that of Bi carbon nanofibers (150.6 mA h g^-1). Furthermore, it retains a capacity retention of 96.07% after 800 cycles, which significantly exceeds that of pristine MoS₂ (72.33 mA h g^-1) as a sodium-ion battery anode. The significant performance improvement originates from the free-standing structural design and synergistic effects of Bi carbon nanofibers, MoS₂ nanospheres and carbon layer, which not only provide 3D electron transport pathways and improved conductivity but also effectively accommodate volume changes during the charging and discharging processes. This work offers a promising and practical strategy for designing high-performance free-standing energy storage electrodes through hybrid mechanisms and synergistic effects.

In the original publication [...].

We investigate the defect-dependent electronic structure and gas-sensing potential of cubic α-CsPbI₃ using first-principles density functional theory and nonadiabatic molecular dynamics. Among the intrinsic defects, interstitials, vacancies, antisites, and switches studied, the I_Pb and Pb_I antisite defects exhibit transition energy levels near the middle of the band gap, thus functioning as deep traps. Short-term adsorption of ammonia selectively modifies the electronic structure, coordinating with Pb at Pb_I sites and Cs at I_Pb sites, significantly altering recombination pathways. Detailed analysis reveals that NH₃ reduces anharmonicity at I_Pb defects, enabling enhanced recombination at elevated temperatures, while trap-assisted recombination dominates at room temperature. Other analytes, including CH₃NH₂ and NO₂, show negligible impact on the band gap or recombination dynamics, highlighting the potential selectivity of NH₃ interactions. Ab initio nonadiabatic molecular dynamics simulations at 300 K and 600 K further demonstrate temperature-dependent modulation of carrier lifetimes, with NH₃ accelerating recombination at ambient conditions and suppressing certain pathways at higher temperatures. These findings suggest that α-CsPbI₃ can serve as a selective and sensitive ammonia sensor over a broad temperature range and offer insights for ammonia detection under industrially relevant conditions.

The interaction between plasmonic nanoparticles and organic dye molecules plays an important role in varied photonic and optoelectronic applications. In this work, we systematically investigate the optical properties of a water-soluble perylenediimide derivative, N,N'-di(2-(trimethylammonium iodide) ethylene) perylenediimide (TAIPDI), in the presence of different concentrations of silver nanoparticles (AgNPs) under femtosecond (fs) laser excitation. The AgNPs were synthesized via the laser ablation technique. The influence of AgNP concentration on the linear, fluorescence, and nonlinear optical properties of the TAIPDI dye was explored through UV-visible absorption spectroscopy, fluorescence emission measurements, and open- and closed-aperture Z-scan techniques. The Ag NP-TAIPDI dye hybrid systems (Ag@TAIPDI nanocomposites) exhibited pronounced reverse saturable absorption and self-defocusing behavior, indicating a negative nonlinear refractive index. Both the nonlinear absorption coefficient and refractive index increased markedly with rising AgNP concentration, leading to a significant enhancement in the third-order nonlinear susceptibility. Fluorescence studies further revealed a concentration-dependent emission enhancement due to metal-enhanced fluorescence arising from surface plasmon resonance-induced local field amplification. The Ag@TAIPDI nanocomposites also demonstrated strong optical limiting performance, with the limiting threshold decreasing as the AgNP concentration increased. These findings highlight the synergistic role of plasmon-exciton coupling and thermal lensing in enhancing the nonlinear response of such nanocomposites. The results establish AgNPs-TAIPDI dye hybrid systems as promising materials for all-optical switching, optical limiting, and photonic device applications.

Stimuli-responsive hydrogels, also referred to as "smart" hydrogels, have emerged as versatile platforms for a wide range of biological and biomedical applications owing to their tunable physical, chemical, and biocompatible properties. Their adaptability arises from both their ability to undergo reversible swelling-deswelling and volume phase transitions in response to specific physicochemical or biological stimuli and the diversity of synthesis strategies that enable precise tailoring of material properties to meet distinct biomedical demands. Recent advances have led to the development of novel hydrogel designs with improved swelling-deswelling behavior, enhanced stimulus sensitivity, and superior biocompatibility, thereby expanding their applicability in complex biological environments. Despite this progress, challenges such as precise control over hydrogel size and relatively slow response kinetics remain critical barriers to broader biomedical and clinical translation. Addressing these limitations requires strategies, including reducing hydrogel particle dimensions to accelerate response rates and engineering heterogeneous or highly porous gel architectures to increase functional surface area. This review provides a comprehensive classification of stimuli-responsive hydrogels based on their physical properties and response mechanisms, and summarizes recent innovations in their design, synthesis, and biomedical applications. Furthermore, it discusses emerging approaches to enhance the clinical applicability of smart hydrogels in controlled drug release, targeted gene delivery, biosensor development, and tissue engineering. Overall, continued optimization of swelling-deswelling characteristics and material design will be essential to fully realize the potential of stimuli-responsive hydrogels in precision medicine and advanced therapeutic applications.

This paper presents the design and experimental validation of a highly sensitive vector magnetic field sensor based on three mutually orthogonal Fabry-Perot interferometers (FPIs). The orthogonally arranged FPIs are bonded to a giant magneto-strictive material (GMM) block. Under an applied magnetic field, the magneto-strictively induced strain in the GMM block is transferred to the FPIs. Meanwhile, the FPIs, composed of single-mode fiber (SMF)-hollow-core fiber (HCF)-SMF, are further modulated by CO₂ laser, by which the higher sensitivities are obtained. The highest sensitivities of FPIs achieved 245.13, 159.06, and 168.59 pm/mT on the X-Y, X-Z, and Y-Z planes, respectively. By demodulating the distinct wavelength drifts of the three orthogonal FPIs, both the magnitude and direction of the magnetic field can be simultaneously determined.

This study presents a SCAPS-1D-based numerical optimization of an organic ultraviolet (UV) photodetector employing an FTO/PTB7/Spiro-OMeTAD/Au device architecture. The novelty of this work lies in a simulation-guided, UV-specific optimization strategy that combines thickness engineering, controlled doping, and contact work-function tuning to achieve intrinsic spectral selectivity without external optical filters. We systematically optimize material and device parameters, including active layer thicknesses, donor and acceptor densities, and the metal electrode work function, to enhance responsivity, detectivity, and spectral performance. Simulations identify optimal thicknesses of 1200 nm for PTB7 and 1000 nm for Spiro-OMeTAD, with donor concentrations of 1 × 10²⁰ cm^-3 and 1 × 10¹⁸ cm^-3, respectively. A comparative contact analysis demonstrates that replacing aluminum with gold (Au) forms a near-ohmic back contact, leading to improved hole extraction and suppressed dark current due to favorable energy-level alignment. The optimized device achieves a peak external quantum efficiency of approximately 80% in the 300-400 nm ultraviolet range, with a responsivity up to 0.4 A/W. The UV selectivity originates from the absorption characteristics of PTB7 combined with suppressed long-wavelength charge collection, resulting in a negligible response in the visible-near-infrared region. These results confirm the device's strong potential for high-sensitivity, solar-blind UV photodetection. By integrating practical material selection with physically consistent SCAPS-1D optoelectronic modeling, this work provides a robust design framework to guide the development of next-generation organic UV photodetectors for environmental sensing, biomedical diagnostics, and wearable optoelectronics.

Dual-emission photoluminescence (PL) nanoprobes provide improved analytical performance to develop a reliable and sensitive sensing platform for quantifying chloramphenicol in pharmaceutical samples, thereby ensuring therapeutic efficacy and patient safety. In this work, a dual-emission PL sensing platform combining carbon dots (CDs) and AgInS₂ quantum dots (QDs) capped with mercaptopropionic acid (MPA) was developed for the quantitative determination of chloramphenicol, resorting to chemometric methods for data analysis. CDs, CdTe QDs, and AgInS₂ QDs were synthesized and individually evaluated considering their photostability, PL response and kinetics of their interaction with the antibiotic. After this, two dual-emission probes, CDs/MPA-CdTe and CDs/MPA-AgInS₂, were prepared and assessed based on the complementarity of their individual emission features. The obtained kinetic PL dataset was processed using unfolded partial least squares (U-PLS) in order to explore the multidimensional information of the dual-emission systems and to evaluate the performance of both sensing platforms. CDs/MPA-AgInS₂ probe was demonstrated to be the most efficient sensing platform due to its better compromise between sensitivity and photostability, as well as its cadmium-free composition, allowing the implementation of a more environmentally friendly analytical methodology. The optimization of the U-PLS models involved the assessment of the kinetic acquisition time and different spectral regions. The results showed that reliable, sensitive and efficient quantification could be achieved within the first 5 min of interaction and using the full emission spectrum of the sensing probe. Additionally, different interaction mechanisms were observed for each nanomaterial in the combined probe, being static for the CDs/chloramphenicol interaction and dynamic for MPA-AgInS₂/chloramphenicol interaction, which supports the synergetic behavior of the combined probe. The proposed methodology was effectively applied to commercial pharmaceutical formulations, yielding accurate results with good figures of merit. Therefore, this approach can be used as a relevant alternative to existing methodologies for a rapid, robust, and environmentally friendly method for chloramphenicol quantification.

This paper reviews the enhancement mechanisms of fatigue performance in titanium alloys processed by laser shock peening (LSP). Because of the redistribution of residual stress and micro-crack and pore behavior, micro-nanostructure evolution and surface roughness effect are systematically discussed. LSP induces beneficial compressive residual stresses at the surface, effectively suppressing crack initiation and propagation. Notably, the nanostructures induced by this process-including nanotwins, dislocations, stacking faults, and nanocrystals-collectively enhance the material's mechanical hardness, strength, and fatigue resistance. Furthermore, LSP reduces porosity, alters pore morphology and alters crack initiation sites, thereby increasing the crack propagation threshold. However, the influence of LSP on material toughness remains a subject of debate. The insights provided herein offer valuable theoretical guidance for the development of high-performance titanium alloys and further optimization of LSP technology.

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