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Bionic SiO2@Fc(COCH3)2 Core-Shell Nanostructure for Enhancing the Electrochromic Properties of Ferrocene
摘要： Although the properties of electrochromic materials (ECMs) have been enhanced using fabricated porous materials, the effect of materials porosity on such an enhancement remains unclear. Here, we report a novel ECMs with an adjustable pore hierarchy based on quasi-amorphous and ordered arrays of SiO2@Fc(COCH3)2. ECMs with different pore systems were generated by modifying Fc(COCH3)2 concentration and self-assembly temperature. The composition and core-shell structure of the SiO2@Fc(COCH3)2 nanospheres were confirmed through scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR) and EDX mapping. The influence of adjustable pore system on the electrochemical behavior was studied. Experimental results showed that the current density of the redox couple peaks of the quasi-amorphous porous SiO2@Fc(COCH3)2 films are considerably lower than those of the ordered porous films but are higher than those of the dense Fc(COCH3)2 films. At 550 nm, the transmittance variation of the quasi-amorphous porous SiO2@Fc(COCH3)2 film is 19 %, whereas that of the ordered porous film is 35 %. The coloration and bleaching times of the quasi-amorphous porous SiO2@Fc(COCH3)2 film are 17.1 s and 4.5 s, respectively, whereas those of the ordered porous film are only 16.5 s and 3.5 s, respectively. Furthermore, the porosities of the films are solved numerically by the finite-element method. For the ordered porous SiO2@Fc(COCH3)2 film, the porosity is 0.26, while the quasi-amorphous film became larger (0.31～ 0.41). This work is the first step in combining ferrocene derivative and colloidal crystal porous structures to develop a green, simple and efficient electrochromic process.
关键词： electrochromism,adjustable porosity,colloidal crystals,ferrocene derivatives,core-shell structure
更新于2025-09-09 09:28:46
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Preparation and application of polystyrene-grafted alumina core-shell nanoparticles for dielectric surface passivation in solution-processed polymer thin film transistors
摘要： Polystyrene-grafted alumina nanoparticles were synthesized by silane coupling between dimethylchlorosilane-terminated polystyrene (PS) and gamma-type alumina nanoparticles and characterized. The surface grafting density of the polystyrene chains on the nanoparticles was estimated to be 0.13 molecules per square nanometer. The Al2O3-PS nanoparticles are solution processable in organic solvents, including ethyl acetate, butyl acetate, and toluene, which enabled preparation of blends with polystyrene or poly(methyl methacrylate). The dielectric constant of the Al2O3-PS nanoparticle/polymer blend films is composition tunable from 2.59 to 7.79. The alumina-PS nanoparticles and their blends with polymers were found to form efficient surface passivation films on the oxide dielectric layer in organic field-effect transistors (OFETs).
关键词： core-shell nanoparticle,alumina-polymer gate insulator,organic field-effect transistor,surface modification
更新于2025-09-09 09:28:46
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Big Potential From Silicon-Based Porous Nanomaterials: In Field of Energy Storage and Sensors
摘要： Silicon nanoparticles (SiNPs) are the promising materials in the various applications due to their unique properties like large surface area, biocompatibility, stability, excellent optical and electrical properties. Surface, optical and electrical properties are highly dependent on particle size, doping of different materials and so on. Porous structures in silicon nanomaterials not only improve the specific surface area, adsorption, and photoluminescence efficiency but also provide numbers of voids as well as the high surface to volume ratio and enhance the adsorption ability. In this review, we focus on the significance of porous silicon/mesoporous silicon nanoparticles (pSiNPs/mSiNPs) in the applications of energy storage, sensors and bioscience. Silicon as anode material in the lithium-ion batteries (LIBs) faces a huge change in volume during charging/discharging which leads to cracking, electrical contact loss and unstable solid electrolyte interphase. To overcome challenges of Si anode in the LIBs, mSiNPs are the promising candidates with different structures and coating of different materials to enhance electrochemical properties. On the basis of optical properties with tunable wavelength, pSiNPs are catching good results in biosensors and gas sensors. The mSiNPs with different structures and modified surfaces are playing an important role in the detection of biomarkers, drug delivery and diagnosis of cancer and tumors.
关键词： lithium ion battery,silicon nanomaterials,bioapplication,porous structures,core shell
更新于2025-09-09 09:28:46
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Characterization of core–shell nanostructure consisting Si–Au–SiO2 based on manipulation of optical properties
摘要： In this article, we investigated some physical characteristics of core–shell nanostructure in optical regime and perturbation has been also introduced as an effective method in shaping of optical properties. The proposed nanostructures are composed of the selected materials as: Silicon, Silicon Dioxide and Gold. At first, the extinction cross section spectra are calculated for multilayer core–shell nanostructures in optical range and the configuration effect of the constructed materials in a multilayer nanostructure are investigated for determination of Plasmon range. Then, the new structures of core–shell nanoparticles (gold–silicon) are presented, which have an amount of impurity particle in their shells as perturbation and also their extinction cross section spectra are calculated. The obtained results in this article give a proper approach about perturbation effect in broadening, sharpening and shifting of optical response which are decisive factors especially nano-network systems. Indeed, it has been proposed that the impurity particles in the shells can be a mechanism for tuning of optical characteristics of the presented nanoparticles in practical fields and also creation of local oscillations as plasmonic resonances in a considered optical range. Besides, redshift in extinction cross section can be also created by particle perturbation. At the end, the effective permittivity of the perturbed core-shells are extracted. The optional frequency range is selected between 300 and 900 (THz).
关键词： Effective permittivity,Perturbation,Nanoparticle impurity,Extinction cross section,Core–shell nanostructure,Plasmonic resonance frequency
更新于2025-09-09 09:28:46
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Fabrication of silver seeds and nanoparticle on core-shell Ag@SiO2 nanohybrids for combined photothermal therapy and bioimaging
摘要： In this study, two core-shell nanohybrids of different morphologies, namely SiO2-coated silver (Ag) with surface-exposed silver seeds (Ag@SiO2@Agseed) and SiO2-coated Ag with surface-exposed Ag nanoparticles (Ag@SiO2@AgNPs), were fabricated using the Stober method. Potential applications in bioimaging and photothermal therapy (PTT) of the two fabricated nanohybrids were also explored. Upon exposure to visible light (400 nm), Ag@SiO2@Agseed with surface-exposed Ag seeds exhibited greater photothermal conversion efficiency than Ag@SiO2@AgNPs. In vitro MTT assays in the dark and subsequent bioimaging using HeLa cells proved the potential biocompatibility of the fabricated core-shell nanohybrids. PTT applications of the two fabricated core-shell nanohybrids were studied by incubating HeLa cells with the nanohybrids, exposure to 400 nm laser, and subsequent staining with annexin V and propidium iodide (PI), and the two core-shell nanohybrids gave distinctively different PI staining results. Interestingly, Ag@SiO2@Agseed caused higher cell death upon light exposure compared to Ag@SiO2@AgNPs as the former generated more heat within the cells. These results demonstrated potential bioimaging and PPT applications of the fabricated core-shell nanohybrids and offer a novel candidate for phototherapy-based biomedical applications.
关键词： Ag@SiO2@AgNPs,Ag@SiO2@Agseed,Photothermal therapy,Core-shell,Bioimaging
更新于2025-09-09 09:28:46
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Synthesis of hierarchical Cu2O octahedra@Ni(OH)2 nanosheets core-shell heterostructures for high-performance supercapacitor
摘要： In this work, we report the controllable preparation of hierarchical Cu2O octahedra@Ni(OH)2 nanosheets core-shell heterostructures and their application in high-performance supercapacitors. Cu2O octahedra are initially directly grown on Ni foam via a facile solvothermal reaction, followed by the covering of Ni(OH)2 nanosheets through a controllable electrodeposition method. The prepared Cu2O@Ni(OH)2 core-shell heterostructures were found to exhibit a specific capacitance of up to 892 F g?1 and a capacitance retention of 95% after 5000 cycles at 5 A g?1. Such good electrochemical performance is believed to arise from its unique octahedra@nanosheets core-shell heterostructures and synergistic effect of the Cu2O and Ni(OH)2 components. Moreover, the assembled Cu2O@Ni(OH)2//active carbon asymmetric supercapacitor device could deliver an energy density of 34.8 W h kg?1 at a power density of 798 W kg?1 at 1 A g?1. Our findings not only suggest the great potential of the prepared Cu2O@Ni(OH)2 core-shell heterostructures for use in energy storage devices, but also showcase an alternative approach to construct the composite electrodes with high electrochemical performance.
关键词： Electrodeposition,Core-shell heterostructure,Cu2O,Ni(OH)2,Supercapacitor
更新于2025-09-09 09:28:46
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Shell Thickness-Dependent Au@Ag Nanoparticles Aggregates for High-Performance SERS Applications
摘要： Plasmonic core-shell nanomaterials have attracted great attention and offered wide applications in surface-enhanced Raman spectroscopy (SERS) due to their unique localized surface plasmon resonance (LSPR) characteristics. In this study, the SERS performance of Ag coated Au nanoparticles aggregates (Au@AgNAs) substrate was explored. The fabrication of Au@AgNAs involved using spherical Au nanocrystals of 32 nm in diameter as the seeds, and ascorbic acid was used as the reductant. The thickness of the Ag shell deposited onto the Au surface was finely tuned from 3 to 13 nm by changing the amount of AgNO3 precursor. Results in this study suggested that the LSPR of the Au core was rapidly attenuated with increasing Ag shell thickness, while the LSPR bands for Ag shell blue-shifted from 390 to 420 nm. Au@AgNAs with the Ag shell thickness of 8.5 nm exhibited excellent SERS activity, which could realize detecting R6G at an ultralow concentration of 1×10?12 M. Besides, the prepared Au@AgNAs showed well homogeneity and reproducibility, and the limit of detection of thiram was calculated as 1.09×10?9 M, indicating that the Au@AgNAs substrate could be potentially used for high-performance SERS sensing applications.
关键词： SERS,core-shell nanoparticles,pesticide,seed-mediated growth,surface plasmonic property
更新于2025-09-09 09:28:46
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Total Aqueous Synthesis of Au@Cu <sub/>2?</sub><i> <sub/>x</sub></i> S Core–Shell Nanoparticles for In Vitro and In Vivo SERS/PA Imaging‐Guided Photothermal Cancer Therapy
摘要： Both accurate tumor navigation and nanostructures with high photothermal (PT) conversion efficiency are important but remain challenging to achieve in current biomedical applications. This study reports an anion exchange-based facile and green approach for synthesizing Au@Cu2?xS core–shell nanoparticles (NPs) in an aqueous system. In addition to the PT effect of the suggested NPs, the surface-enhanced Raman scattering (SERS) is also significantly improved due to the tailored localized surface plasmon resonance coupling between the Au metal core and the Cu2?xS semiconductor shell. Using an epitaxial strategy, Au@Cu2O NPs are first obtained by the in situ reduction of cupric hydroxide on a cresyl violet acetate-coated Au core; then, Au@Cu2?xS NPs are obtained via anion exchange between the S2? and Cu2O shell. Both the Cu/S atomic ratio and the Cu2?xS shell thickness can be adjusted conveniently. Hence, the ideal integration of the plasmonic Au core and Cu2?xS shell into a single unit is conducive not only to highly efficient PT conversion but also to the construction of a SERS-based navigator. This new type of SERS-guided NP, with enhanced photoacoustic signals, is an important candidate for both accurate tumor navigation and nondestructive PT treatment guided in vivo by two modes of optical imaging.
关键词： navigation treatment,photothermal therapy (PTT),Au@Cu2?xS core–shell nanoparticles (NPs),plasmonic enhancement,surface-enhanced Raman scattering (SERS)
更新于2025-09-09 09:28:46
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Nanodisc decorated W-WOx suspended nanowire: A highly sensitive and selective H2S sensor
摘要： In this work we report room temperature synthesis of plasma oxidized, suspended tungsten-tungsten oxide (W-WOx) core-shell nanowire for sensing ppb level H2S. The electric field modulation at the W-WOx interface of the core-shell nanowire strongly influences the sensing performance and brings down the operating temperature all the way down to 50°C, compared to completely oxidized (WOx) nanowire. The optimum interface ratio (W/WOx) of the nanowire shows response of 90.4% (1 ppm) with 6 months of response stability and excellent selectivity. The limit of detection of 10 ppb with response and recovery time of 4 s and 46 s respectively is achieved. To enhance the response further, we utilize nanostructuring on top of nanowire, using nanodiscs of 20 nm, 50 nm and 100 nm diameter and 10 nm height. The nanowire with nanodiscs of 20 nm diameter shows the high repeatable response of 12529% (1 ppm) at 150°C and fast response and recovery times of 12 s and 19 s with detection limit of 0.5 ppb. As we switch from unpatterned to patterned nanowire the observed change in H2S sensing characteristics, indicates that the core-shell nanowire behaviour makes a transition from p-type to n-type. Extensive material characterization is done using UV-Vis spectroscopy, XPS and TEM.
关键词： plasma oxidation,selectivity,Core-shell nanowire,nanodiscs,suspended
更新于2025-09-09 09:28:46
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SERS effect on the presence and absence of rGO for Ag@Cu2O core-shell
摘要： Graphene nanosheets have been widely used to study the surface-enhanced Raman scattering (SERS) enhancement mechanism. However, the effect of graphene on the field distribution in specific nanocomposite structures was unclear. Therefore, it is important to study the effect of reduced graphene oxide (rGO) in metal-semiconductor core-shell structures based on SERS. The enhancement factors (EF) was changed significantly in the presence and absence of the rGO substrate with the green and red laser excitations. Experimental and theoretical simulations results demonstrate that rGO platform plays an important role in enhancing SERS activity of single Ag@Cu2O core-shell particles. This research with respect to rGO-based SERS substrates will expand the basic theoretical research of nanomaterials and provide a theoretical basis for optoelectronic research.
关键词： rGO platform,Ag@Cu2O core-shell,SERS
更新于2025-09-09 09:28:46