- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- 2018
- silver nanowires
- nanopaper
- transparent electrode
- flexible
- composite electrode
- silver nanowire
- reduced graphene oxide
- zinc oxide
- Nanomaterials and Technology
- Optoelectronic Information Materials and Devices
- South China University of Technology
- China Jiliang University
- Guangdong Poly-Optoelectronics Co.
-
Sensitive surface-enhanced Raman scattering substrates based on anti-pyramidal gold architectures decorated with silver nanoparticles
摘要： A micro-structured gold surface, consisting of a periodic square–based anti–pyramidal array (Klarite) with a smooth boundary surface on which silver nanoparticles (diameter: 60 nm) were deposited, produced an active surface enhanced Raman scattering substrate. With p-aminothiophenol as a probe molecule, the Raman activity of the micro–structured surface was compared before and after deposition of the silver nanoparticles. Experimental results show that the Raman spectra on the silver/p-aminothiophenol/Klarite structure is stronger than that on the silver/p-aminothiophenol/gold film and the Raman spectra on the silver/p-aminothiophenol/gold film is stronger than that on silver/p-aminothiophenol, p-aminothiophenol/Klarite structure, p-aminothiophenol/gold film, which is confirmed by numerical simulations. A similar result is obtained with crystal violet as test molecule.
关键词： Anti-pyramidal architectures,surface enhanced Raman scattering,p-aminothiophenol,silver nanoparticles
更新于2025-09-23 15:21:21
-
Light and pressure sensors based on PVDF with sprayed and transparent electrodes for self-powered wireless sensor nodes
摘要： In this work, we report on the fabrication of light and pressure sensors based on the piezo-and pyro material polyvinylidene fluoride (PVDF). In addition to the operation as sensors, the presented devices are characterized as energy harvesters. To form an electrical connection to the 39 μm thick PVDF foil, solution-based and transparent electrode (TE) materials such as silver nanowires (AgNWs) and poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) are utilized and compared with commercial aluminum electrodes on polymer substrate. We show that the performance with regard to sensitivity and generated output power of the TE-PVDF devices outperforms the one for the aluminum foil devices. For the piezo- and pyroelectric effect, a pressure and light sensitivity of 3.6 mV/Pa and 42 V cm2/W, respectively, are measured. The maximum RMS power for the piezo- and pyro effect yield to 1 μW and 0.42 μW, respectively, for an active PVDF area of 8 cm2. At the end of this contribution, we show that this power suffices to drive an energy autarkic wireless sensor node (WSN) that is capable of measuring and transmitting an analog sensor signal using ultra-low power components. This application contributes substantially to the notion of the internet of things (IoT) since paramount aspects such as wireless technology, embedded electronics, and environmental sensor data together with an ultra-low power management are addressed.
关键词： wireless sensor nodes,PEDOT:PSS,WSN,Internet of Things,IoT,spray deposition,energy harvesting,silver nanowires,transparent electrodes
更新于2025-09-23 15:21:21
-
Controlling surface morphology and sensitivity of granular and porous silver films for surface-enhanced Raman scattering, SERS
摘要： The design of efficient substrates for surface-enhanced Raman spectroscopy (SERS) for large-scale fabrication at low cost is an important issue in further enhancing the use of SERS for routine chemical analysis. Here, we systematically investigate the effect of different radio frequency (rf) plasmas (argon, hydrogen, nitrogen, air and oxygen plasma) as well as combinations of these plasmas on the surface morphology of thin silver films. It was found that different surface structures and different degrees of surface roughness could be obtained by a systematic variation of the plasma type and condition as well as plasma power and treatment time. The differently roughened silver surfaces act as efficient SERS substrates showing greater enhancement factors compared to as prepared, sputtered, but untreated silver films when using rhodamine B as Raman probe molecule. The obtained roughened silver films were fully characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron (XPS and Auger) and ultraviolet–visible spectroscopy (UV–vis) as well as contact angle measurements. It was found that different morphologies of the roughened Ag films could be obtained under controlled conditions. These silver films show a broad range of tunable SERS enhancement factors ranging from 1.93 × 102 to 2.35 × 105 using rhodamine B as probe molecule. The main factors that control the enhancement are the plasma gas used and the plasma conditions, i.e., pressure, power and treatment time. Altogether this work shows for the first time the effectiveness of a plasma treatment for surface roughening of silver thin films and its profound influence on the interface-controlled SERS enhancement effect. The method can be used for low-cost, large-scale production of SERS substrates.
关键词： plasma treatment,sputtering,surface-enhanced Raman spectroscopy (SERS),silver,surface roughening
更新于2025-09-23 15:21:21
-
GREEN SYNTHESIS OF SILVER NANOPARTICLES FROM AQUEOUS STEM EXTRACT OF CERIOPS TAGAL
摘要： Biosynthesis of reliable and eco-friendly nanoparticles is an important branch of green nanotechnology. Ceriops tagal, a mangrove plant has various medicinal properties. Synthesis of C.tagal mediated nanoparticles may further enhance its medicinal potency. The aqueous stem extract of C.tagal was used as a bio-reducing agent for synthesis of silver nanoparticles Reduction of metal ions was confirmed by Ultraviolet-visible absorption spectroscopy, transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. Before and after bio-reduction changes in functional groups of plant extract was recorded by FTIR spectra. The kinetics of particle formation was dependent on time, temperature and metal salt concentration. UV-Visible spectroscopy demonstrated peak at 455 nm. TEM and XRD results revealed shapes, size and structure of synthesized nanoparticles. These results have indicated the formation of silver nanoparticles.
关键词： Mangroves,silver nanoparticles,aqueous extract,Ceriops tagal
更新于2025-09-23 15:21:21
-
Surface-nanostructured single silver nanowire: a new one-dimensional microscale SERS interface
摘要： One-dimensional microscale SERS-active interfaces have been intriguing as a newly emerging class of SERS interfaces compared to conventional macroscale SERS substrates. In this work, a stable surface-nanostructured single silver nanowire was fabricated. The nanostructures on the nanowire are formed by nanoscale silver crystal dots with diameters of 20-50 nm. The SERS signals of the crystal violet probe molecules adsorbed on the nanostructures are dramatically enhanced by both electromagnetic and chemical effects. The hot spots generated at the junctions of adjacent nanoscale dots yield highly efficient surface plasmon resonance. Simultaneously, the charge transfer on the atomic-scale silver cluster located at the nanostructured interface causes an enhancement similar to a Raman resonance. The intensity distributions of the SERS peaks on the surface-nanostructured single nanowire are characterized by SERS mapping. It is found that, although the intensities of the SERS peaks are different, their SERS mapping images show uniform SERS enhancement distributions, whereas the noticeable SERS intensity distributions on the single smooth silver nanowire are mainly located on the two ends of the nanowire. The large number of nanoscale crystal dots along with the atomic-scale silver clusters are uniformly and densely distributed on the surface of the single roughened nanowire; these structural attributes induce a uniform and large surface plasmon resonance and charge transfer enhancements on the entire surface of the nanowire. This work indicates that the surface-nanostructured single silver nanowire, synthesized using a quite simple preparation method, performs as an excellent one-dimensional microscale SERS substrate with uniform and high enhancement characteristics, which shows high potential for applications as a new class of SERS-active substrates. Furthermore, the higher enhancement factor of the microscale SERS interfaces can be achieved by introducing other roughened nanowires to assemble a dimer and a trimer as micro SERS substrates, which is consistent with the dark field (DF) measurements.
关键词： Hot spots,Raman,Micro SERS interfaces,Charge transfer,Silver nanowire
更新于2025-09-23 15:21:21
-
Atomic diffusion induced by electron-beam irradiation: An <i>in situ</i> study of Ag structures grown from <i>α</i> -Ag <sub/>2</sub> WO <sub/>4</sub>
摘要： In this paper, we investigate the structural and morphological changes caused by the electron-beam irradiation that led to the growth of complex extruded filaments on the surfaces of α-Ag2WO4. To provide a complete description of this phenomenon, both scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed in this study. Our experimental results evidenced that the extruded material was able to growth in different crystallographic faces, depending on the kind of microscope adopted during the electron-beam irradiation. For a more complete analysis, different electron-beam current densities in TEM were used to investigate all in situ modifications in the microcrystals. For the first time, besides the metallic silver, the presence of silver oxides (Ag2O and Ag3O4) were detected in the composition of extruded material. The diffusion mechanisms related to morphological modifications in the samples irradiated in SEM and TEM were discussed in details. The co-precipitation reaction in dimethyl sulfoxide was chosen as synthetic route, which favored the appearance of rectangular rod-like α-Ag2WO4 microcrystals. A growth mechanism was proposed to explain the formation and growth processes of these microcrystals.
关键词： silver filaments,α-Ag2WO4,silver oxides,electron-beam irradiation,diffusion mechanisms
更新于2025-09-23 15:21:01
-
Controlled synthesis of AgNPs@ZIF-8 composite: Efficient heterogeneous photocatalyst for degradation of methylene blue and congo red
摘要： Photocatalytic degradation of organic dyes using novel metal based composite materials is one of the most intriguing and sustainable ways to reduce water pollution. Herein, facile synthesis of AgNPs@ZIF-8 via in situ generation of AgNPs and ZIF-8 (Zeolitic Imidazolate Framework) was demonstrated, and composites with different Ag contents (abbreviated as SZ, SZ1, SZ2 SZ3) were well characterized by powder X-ray diffraction (PXRD) pattern, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red (FT-IR) spectroscopy. Encapsulation/decoration of AgNPs (particle size: 96 nm in SZ and 17.32 ± 2.35 nm in SZ1 to SZ3) in ZIF-8 matrix has been ensured by TEM and EDX analysis. Brunauer-Emmett-Teller (BET) adsorption-desorption studies indicate that the surface area of SZ (982 m2 g?1) is less than those of SZ1 to SZ3 (due to the encapsulation of large amount of Ag nanoparticles in SZ). The synthesized composites are thermally stable up to 400 °C in air and nitrogen atmosphere. AgNPs@ZIF-8 exhibited excellent photocatalytic efficiency to degrade organic dyes compared to ZIF-8 due to its large surface area, highly porous and unique synergistic properties. SZ2 degrades off 97.25 % methylene blue (MB) and 100 % congo red (CR) at pH ≥ 7. Further, degraded fragments were analysed by GC–MS and plausible degradation mechanism was discussed.
关键词： Silver nanoparticles,Organic pollutants,Photocatalyst,Heterogeneous catalysis,Composite materials
更新于2025-09-23 15:21:01
-
Optical sensors based on silver nanoparticles for determination of pharmaceuticals: An overview of advances in the last decade
摘要： This review focuses on optical nanosensors based on silver nanoparticles (Ag NPs) and demonstrates their applications in the determination of pharmaceutical compounds in the last decade. Such optical sensors have received high attention in the analytical field owing to their low cost and simplicity since they do not require any complex or expensive instrumentation. This article reviews Ag NP-based optical methods for the determination of pharmaceutical compounds from 2010 to 2020. The reported optical methods are classified into four types: spectrophotometry, spectrofluorimetry, scattering and chemiluminescence. Ag NPs play different roles in the different sensing platforms used by these methods, the details of which are carefully explained in this review. Moreover, the relevant analytical parameters of the developed methods are categorized by role and tabulated. It is hoped that this review will stimulate further research in this field with similar nanostructures.
关键词： Silver nanoparticles,Optical sensors,Pharmaceutical compounds
更新于2025-09-23 15:21:01
-
[IEEE 2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP) - Zatoka, Ukraine (2018.9.9-2018.9.14)] 2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP) - The Study of the Activation of Antibacterial Activity of Silver Nanoparticles by Laser Radiation
摘要： Silver nanoparticles are known to have inhibitory and bactericidal effects and they play a significant role in the development of new antimicrobial substances against pathogenic microorganisms. In this article the minimum bactericidal concentration of the silver nanoparticles on two different bacteria cultures (Escherichia coli and Staphylococcus aureus) as well as the possibility to enhance their antimicrobial activity using laser irradiation was investigated. It was found, that solutions of silver nanoparticles at concentrations ≥ 3120 μg/ml cause death of both types of studied microorganisms. Dispersion of nanoparticles after laser irradiation caused the inhibition of Staphylococcus aureus at lower concentrations.
关键词： surface plasmon resonance,Escherichia coli,Staphylococcus aureus,bactericidal properties,silver nanoparticles
更新于2025-09-23 15:21:01
-
Rational Interface Engineering for Efficient Flexible Perovskite Light-Emitting Diodes
摘要： Although perovskite light-emitting diodes (Pe-LEDs) are promising for next-generation displays and lighting, their efficiency is still considerably below that of conventional inorganic and organic counterparts. Significant efforts in various aspects of the electroluminescence process are required to achieve high-performance PeLEDs. Here, we present an improved flexible PeLED structure based on the rational interface engineering for energy-efficient photon generation and enhanced light outcoupling. The interface-stimulated crystallization and defect passivation of the perovskite emitter are synergistically realized by tuning the underlying interlayer, leading to the suppression of trap-mediated nonradiative recombination losses. Besides approaching highly emissive perovskite layers, the outcoupling of trapped light is also enhanced by combining the silver nanowires-based electrode with quasi-random nanopatterns on flexible plastic substrate. Upon the collective optimization of the device structure, a record external quantum efficiency of 24.5% is achieved for flexible PeLEDs based on green-emitting CsPbBr3 perovskite.
关键词： defect passivation,flexible perovskite light-emitting diodes,perovskite light-emitting diodes,silver nanowires,light outcoupling
更新于2025-09-23 15:21:01