Surface Of Ag Nanowires Research Articles

A Dual-Function AgNW@COF SERS Membrane for Organic Pollutant Removal and Simultaneous Concentration Determination.

Surface enhanced Raman spectroscopy (SERS) is a highly sensitive analytical detection method commonly employed in biochemical and environmental analysis. Nevertheless, the rapid movement of analytes and interfering components in flow systems can impact the real-time, online detection capability of Raman spectroscopy. To address this issue, we developed an innovative approach utilizing covalent organic framework (COF), a robust porous material with excellent water stability, to coat the surface of Ag nanowire (AgNW) for synthesizing AgNW@COF hybrid. The regular pores of the COF serve to effectively eliminate large interfering molecules while facilitating the efficient transport of specific analytes to SERS hot spots. Additionally, the fluid flow-induced scouring effect aids in excluding interfering molecules from the surface of AgNW. By incorporating AgNW@COF into a bifunctional filter membrane with simultaneous filtration and sensing capabilities, we had achieved efficient purification of organic pollutants as well as real-time identification of pollutant species and concentration.

Ultra-stable Ag NWs transparent conductive film protected by AgCl and PbO2 passivation layer

AgCl and PbO2 protective passivation layer on the surface of Ag nanowires (Ag NWs) were successfully fabricated by two facile methods. The as-obtained Pb2+/Ag NWs and Fe3+/Ag NWs transparent conductive films exhibited remarkable high-temperature oxidation resistance, stable optoelectronic properties, acid and alkali resistance. The sheet resistance of the Pb2+/Ag NWs and Fe3+/Ag NWs transparent conductive film could be detected even after etched by 1 M HCl and NaOH for 4 h. Furthermore, the constructing protective passivation monolayer acts as a shelter protecting the Ag nanowires from chemical and structural damage. The network structure of Pb2+/Ag NWs and Fe3+/Ag NWs transparent conductive film contact each other after the heat treatment temperature exceeds 300 ℃. The transmittance changed from 86.9 % to 81.4 % and the sheet resistance of Pb2+/Ag NWs transparent conductive film shown a smaller change trend, which verified that the film has enhanced highly. environmental stability.

Controlled Synthesis of Ag@Polythiophene Nanocables by Ion Adsorption Technique

Ag@Polythiophene nanocables were synthesized by Ion Adsorption Technique. In this approach, the pre-synthesized Ag nanowires were dispersed in aqueous solution of copper acetate and the Cu2+ ions adsorbed onto the surface of Ag nanowires. These nanowires were then redispersed in aqueous solution of thiophene. The adsorbed Cu2+ ions oxidized thiophene monomer to polymerize into uniform polythiophene sheath outside Ag nanowires. Thus, it has transformed pre-synthesized Ag NWs into polythiophene Nanocables (NCs). The morphology of pristine Ag NWs and Ag@polythiophene NCs were characterized by scanning electron microscopy (SEM), which showed sheathing effect at Ag NWs and indicated the successful coating over its surface. Optical and electronic properties were determined by UV-Vis spectroscopy and PL spectroscopy. The functional groups were determined by Fourier transform infrared spectroscopy (FT-IR). The peaks at 1482 cm-1, 1625 cm-1, 1223 cm1, 825 cm-1 and 722 cm-1 confirmed the polythiophene coating on Ag NWs. Furthermore, the thermal stability was monitored by thermogravimetric analysis (TGA) which showed enhanced thermal stability of Ag@Polythiophene nanocables as compared to pristine Ag NWs.

Ag@ZIF-67 nanocomposites for ultra-sensitive SERS detection to thiram molecules

Surface-enhanced Raman scattering technique has become a powerful tool for detecting trace targets in the field of food-safety. However, it is a challenge to regulate the hot spots of the detection substrate and its interaction with target molecules for the enhancement of SERS activity. Herein, we reported the high performance SERS substrate based on Ag@ZIF-67 nanocomposite with sugar-coated haws like structure. It was found that the coverage of ZIF-67 particles on the surface of Ag nanowires can adjust the SERS ability of detection substrate. Compared with pure Ag nanowires, functionalized Ag nanowires exhibit outstanding SERS activity with good stability and uniformity. The detection limit of crystal violet and thiram can be as low as 10−10 M and 10−8 M, respectively. After 35 d, the SERS activity remains basically unchanged. Furthermore, it also has excellent SERS response to 5 10−5 M thiram residues on the surface of vegetables. Such high SERS activity can be attributed to the enrichment and screening molecular effect of porous ZIF-67 nanoparticles, and the surface plasmon resonance effect of Ag nanowires. This work provides a simple strategy for the on-site detection of pesticide residues in the actual applications.

In-situ electrochemical fabrication of Ag@AgCl NW-PET film with superior photocatalytic bactericidal activity

Constructing a composite photocatalyst with efficient charge-transfer pathways is contribute to improving charge separation, which has attracted wide attention owing to its availability in photocatalysis applications. In this work, three-dimensional (3D) silver@silver chloride (Ag@AgCl) network structures are fabricated for photocatalytic inactivation of Escherichia coli (E. coli) by the in situ electrochemical introducing AgCl shell on the surface of Ag nanowire (NW) networks that are coated on a polyethylene terephthalate (PET) substrate. The obtained Ag@AgCl NW-PET films exhibit good photocatalytic bactericidal activity against E. coli under simulated Sunlight irradiation, mainly due to their efficient charge-transport channel constructed by the Ag NWs network. It is worth noting that the content of converted AgCl shell is positively correlated with their photocatalytic bactericidal efficiency. The experimental results also demonstrate that the synergistic contribution of Ag+ sustained release, rough surfaces and energy band structure optimization in photocatalytic sterilization. Besides, the prepared Ag@AgCl NW-PET film can be recycled, and the photocatalytic sterilization efficiency can still keep above 99% after three cycles. This work might provide new and more diverse opportunities for the development of excellent charge-transport, recyclable photocatalysts for photocatalytic sterilization.

Enhancement of electrical and thermal properties of silver nanowire transparent conductive electrode by Ag coating

In this study, Ag nanowires (AgNWs) were synthesized by the polyol method at 160 °C under nitrogen atmosphere. AgNW transparent conductive electrodes (TCE) were fabricated on a glass slide, and an Ag layer was coated onto the AgNWs to improve their electrical and thermal properties. The AgNWs had diameters in the range of 25–54 nm, aspect ratio up to 1000 and high yield (>90%) when used with the mixture of halide ions Cl− and Br−. After coating an Ag layer on the surface of AgNW of TCEs by electrodeposition, the electrical and thermal properties was improved significantly. The sheet resistance decreased from ∼247 Ω/□ to approximately 10 Ω/□ and the thermal stability was improved by 20 °C in comparison with bare AgNW TCEs. The best sample was observed at an electrodepositing current of 1 mA for 40 s; the sheet resistance, transmittance, and figure of merit of this sample were ∼8.5 Ω/□, 85.4%, and 271 Ω−1, respectively.

Electroplated core\u2013shell nanowire network electrodes for highly efficient organic light-emitting diodes

In this study, we performed metal (Ag, Ni, Cu, or Pd) electroplating of core–shell metallic Ag nanowire (AgNW) networks intended for use as the anode electrode in organic light-emitting diodes (OLEDs) to modify the work function (WF) and conductivity of the AgNW networks. This low-cost and facile electroplating method enabled the precise deposition of metal onto the AgNW surface and at the nanowire (NW) junctions. AgNWs coated onto a transparent glass substrate were immersed in four different metal electroplating baths: those containing AgNO3 for Ag electroplating, NiSO4 for Ni electroplating, Cu2P2O7 for Cu electroplating, and PdCl2 for Pd electroplating. The solvated metal ions (Ag+, Ni2+, Cu2+, and Pd2+) in the respective electroplating baths were reduced to the corresponding metals on the AgNW surface in the galvanostatic mode under a constant electric current achieved by linear sweep voltammetry via an external circuit between the AgNW networks (cathode) and a Pt mesh (anode). The amount of electroplated metal was systematically controlled by varying the electroplating time. Scanning electron microscopy images showed that the four different metals (shells) were successfully electroplated on the AgNWs (core), and the nanosize-controlled electroplating process produced metal NWs with varying diameters, conductivities, optical transmittances, and WFs. The metal-electroplated AgNWs were successfully employed as the anode electrodes of the OLEDs. This facile and low-cost method of metal electroplating of AgNWs to increase their WFs and conductivities is a promising development for the fabrication of next-generation OLEDs.

A simple and effective method via PH1000 modified Ag-Nanowires electrode enable efficient flexible nonfullerene organic solar cells

Flexible transparent electrodes (FTEs) play an important role in determining the performance of flexible organic solar cells (OSCs), Ag-nanowires (AgNWs) with the unique merits of high conductivity, excellent flexibility, and good thermal stability has been taken into more consideration in fabricating highly efficient FTEs. However, the pristine AgNWs film usually suffers a huge surface roughness and incompatibility with the organic absorption layer, thus always leads to a poor power conversion efficiency (PCE). Herein, we demonstrated a simple and effective way through employing poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PH1000) to modify the surface of AgNWs to prepare high-quality FTEs. Based on the PH1000 (100 nm)/AgNWs FTEs, the optimized flexible OSC with PM6:Y6 as active layer exhibits a highest PCE of 12.71%, with an open-circuit voltage ( V oc ) of 0.814 V, a short-circuit current ( J sc ) of 22.61 mA/cm 2 , and a fill factor ( FF ) of 0.691, respectively. Which is much higher than the PCE (7.20%) of pristine AgNWs FTEs based device. The enhanced device performance was attributed to the improved morphologies both of the FTEs and the active layers, more effective charge transport and collection efficiency, as well as the decreased charge recombination properties. This work provides an efficient way to fabricate high-quality FTEs and realize efficient flexible OSCs. The significant improvement on the performance of flexible organic solar cells is achieved by employing PH1000 to modify AgNWs transparent electrodes. This work provides a simple and effective way to realize efficient flexible OSCs. • PH1000/AgNWs flexible transparent electrodes (FTEs) was prepared. • A highest PCE of 12.71% of flexible OSCs was realized. • This work provides an efficient way to fabricate high-quality FTEs and realize efficient flexible OSCs.

Facile Synthesis of Ag Nanowire/TiO2 and Ag Nanowire/TiO2/GO Nanocomposites for Photocatalytic Degradation of Rhodamine B.

This paper investigates the photocatalytic characteristics of Ag nanowire (AgNW)/TiO2 and AgNW/TiO2/graphene oxide (GO) nanocomposites. Samples were synthesized by the direct coating of TiO2 particles on the surface of silver nanowires. As-prepared AgNW/TiO2 and AgNW/TiO2/GO nanocomposites were characterized by electron microscopy, X-ray diffraction, UV/visible absorption spectroscopy, and infrared spectroscopy. Transmission electron microscope (TEM) images confirmed the successful deposition of TiO2 nanoparticles on the surface of AgNWs. The photocatalytic activity of synthesized nanocomposites was evaluated using Rhodamine B (RhB) in an aqueous solution as the model organic dye. Results showed that synthesized AgNW/TiO2/GO nanocomposite has superior photocatalytic activities when it comes to the decomposition of RhB.

Template-Free and Surfactant-Free Synthesis of Selective Multi-Oxide-Coated Ag Nanowires Enabling Tunable Surface Plasmon Resonance.

Without using templates, seeds and surfactants, this study successfully prepared multi-oxide-layer coated Ag nanowires that enable tunable surface plasmon resonance without size or shape changes. A spontaneously grown ultra-thin titania layer onto the Ag nanowire surface causes a shift in surface plasmon resonance towards low energy (high wavelength) and also acts as a preferential site for the subsequent deposition of various oxides, e.g., TiO2 and CeO2. The difference in refractive indices results in further plasmonic resonance shifts. This verifies that the surface plasma resonance wavelength of one-dimensional nanostructures can be adjusted using refractive indices and shell oxide thickness design.

Controlling crystal growth of MIL-100(Fe) on Ag nanowire surface for optimizing catalytic performance.

Ag/MIL-100(Fe) core/sheath nanowire with controllable thickness of the MIL-100(Fe) sheath was prepared by controlling the crystal growth of MIL-100(Fe) on the Ag nanowire surface. The evolution of the MIL-100(Fe) sheath monitored by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FT-IR), and N2 adsorption–desorption analysis indicates that the thickness of the MIL-100(Fe) sheath increases with the increasing number of crystal growth cycles of MIL-100(Fe) on the Ag nanowire surface. Catalytic reaction over Ag/MIL-100(Fe) core/sheath nanowire suggests that the thickness of the MIL-100(Fe) sheath largely influences the catalytic performance and it is quite important to control the crystal growth of MIL-100(Fe) on the Ag nanowire surface for optimizing catalytic performance.

Protecting the Nanoscale Properties of Ag Nanowires with a Solution-Grown SnO2 Monolayer as Corrosion Inhibitor

The chemical reactivity and/or the diffusion of Ag atoms or ions during thermal processing can cause irreversible structural damage, hindering the application of Ag nanowires (NWs) in transparent conducting films and other applications that make use of the material's nanoscale properties. Here, we describe a simple and effective method for growing monolayer SnO2 on the surface of Ag nanowires under ambient conditions, which protects the Ag nanowires from chemical and structural damage. Our results show that Sn2+ and Ag atoms undergo a redox reaction in the presence of water. First-principle simulations suggest a reasonable mechanism for SnO2 formation, showing that the interfacial polarization of the silver by the SnO2 can significantly reduce the affinity of Ag to O2, thereby greatly reducing the oxidation of the silver. The corresponding values (for example, before coating: 17.2 Ω/sq at 86.4%, after coating: 19.0 Ω/sq at 86.6%) show that the deposition of monolayer SnO2 enables the preservation of high transparency and conductivity of Ag. In sharp contrast to the large-scale degradation of pure Ag-NW films including the significant reduction of its electrical conductivity when subjected to a series of harsh corrosion environments, monolayer SnO2 coated Ag-NW films survive structurally and retain their electrical conductivity. Consequently, the thermal, electrical, and chemical stability properties we report here, and the simplicity of the technology used to achieve them, are among the very best reported for transparent conductor materials to date.

Using Electrospun AgNW/P(VDF-TrFE) Composite Nanofibers to Create Transparent and Wearable Single-Electrode Triboelectric Nanogenerators for Self-Powered Touch Panels.

Self-powered sensors have attracted significant interest for individual wearable device operation. Here, transparent and wearable single-electrode triboelectric nanogenerators (SETENGs) with high power generation are created using electrospun Ag nanowires (AgNWs)/poly(vinylidenefluoride-cotrifluoroethylene) [P(VDF-TrFE)] composite nanofibers (NFs). The SETENGs generate an output power density of up to 217 W/m2 with repetitive contact and separation from the surface of a latex glove. In electrospun P(VDF-TrFE) NFs, the crystalline β-phase is highly oriented by oxygen-containing functional groups on the surface of AgNWs, endowing the F-rich surface with high electron negativity and enabling efficient triboelectrification. Additionally, 80% transmittance at a light wavelength of 550 nm, mechanical stability, and durability after 10 000 cycles at 10% strain are confirmed by filling the NF pores with plasma desorption mass spectrometry. Our SETENG acts as an effective energy harvester by powering 45 light-emitting diodes and as an excellent real-time, self-powered touch panel.

Efficient Passivation of Ag Nanowires with 11‐Mercaptoundecanoic Acid Probed Using In Situ Total‐Internal‐Reflection Surface‐Enhanced Raman Scattering Spectroscopy

AbstractA promising passivation strategy of one class of Ag nanostructures of high interest for optoelectronics, namely Ag nanowires (AgNWs), with 11‐mercaptoundecanoic acid (MUA) is described. Combining XPS, electron microscopy and original in‐situ total‐internal‐reflection (TIR) surface‐enhanced Raman scattering (SERS) spectroscopic measurements, the substitution of polyvinylpyrrolidone (PVP) molecules on as‐synthesized PVP‐coated AgNWs by their MUA counterparts is clearly demonstrated. The relevance of the SERS approach to examine the anchoring of the MUA onto the silver surface of specific AgNWs with pentagonal cross‐sections is supported by FDTD simulations. In particular, the TIR‐SERS technique reveals that the PVP‐MUA substitution process can be divided into two main steps, namely (i) the desorption of PVP molecules associated with the anchoring of MUA molecules via the formation of Ag−OOC and Ag−S bonds (accomplished within 40 min), and (ii) the subsequent reorientation of MUA molecules to form only Ag−S bonds (finished in 90 min). The resulting passivation of AgNWs with MUA significantly improves their resistance to corrosion, which is crucial for future commercial applications.

Formation of core-shell structure from carbon nanotube and silver nanowire

In recent year, carbon materials have attracted an intensive interest for scientists to propel the development of nanotechnology. In this manuscript, using forced-field-based molecular dynamics simulations, the interaction between the carbon nanotubes (CNTs) and silver (Ag) nanowires (NWs) has been investigated. The results show that the Ag NW can induce the self-assembly of the CNTs to form a shell-core structure, and the van der Waals interaction and the offset face-to-face π-π stacking interaction play an important role in this process. Furthermore, the size (diameter) of the CNTs should meet some required conditions to guarantee the shell-core configuration and different surface of Ag NWs exhibits different result. Moreover, different metal nanowires were also discussed.

Color-Tunable ZnO/GaN Heterojunction LEDs Achieved by Coupling with Ag Nanowire Surface Plasmons.

Color-tunable light-emitting devices (LEDs) have a great impact on our daily life. Herein, LEDs with tunable electroluminescence (EL) color were achieved via introducing Ag nanowires surface plasmons into p-GaN/n-ZnO film heterostructures. By optimizing the surface coverage density of coated Ag nanowires, the EL color was changed continuously from yellow-green to blue-violet. Transient-state and temperature-variable fluorescence emission characterizations uncovered that the spontaneous emission rate and the internal quantum efficiency of the near-UV emission were increased as a consequence of the resonance coupling interaction between Ag nanowires surface plasmons and ZnO excitons. This effect induces the selective enhancement of the blue-violet EL component but suppresses the defect-related yellow-green emission, leading to the observed tunable EL color. The proposed strategy of introducing surface plasmons can be further applied to many other kinds of LEDs for their selective enhancement of EL intensity and effective adjustment of the emission color.

Enhanced conductivity of transparent and flexible silver nanowire electrodes fabricated by a solution-processed method at room temperature

A simple method was developed to increase the electrical conductivity of Ag nanowire (NW) transparent electrodes prepared at room temperature. By dipping Ag NW coated poly(ethylene terephthalate) (PET) film into AgBr solution with sodium ascorbate as reductant, Ag nanoparticles grow on the surface of Ag NWs and their junction positions. It was found that the attachment of Ag nanoparticles on Ag NWs decreases the electrode film resistance from 220–300Ω/sq. to 30–50Ω/sq., which is mainly due to the change in junction resistance with Ag nanoparticles functioning as a bridge for electron transportation between Ag NWs. Ag NW coated PET films have a transmittance of 85.0% at the spectral wavelength of 550nm, and this value does not change much after AgBr treatment. A mechanical study shows that Ag NW electrodes on flexible substrates have excellent robustness subjected to bending. The properties of transparent Ag NW electrodes prepared using our method meet the requirements of transparent electrodes for many applications and could be a replacement for indium tin oxide for flexible electronics and solar cells.

Enhanced near-UV electroluminescence from p-GaN/i-Al2O3/n-ZnO heterojunction LEDs by optimizing the insulator thickness and introducing surface plasmons of Ag nanowires

Enhanced near-UV electroluminescence is achieved from p-GaN/i-Al2O3/n-ZnO LEDs by optimizing the Al2O3 insulator thickness and introducing Ag nanowire surface plasmons.

Creation of Controllable High-Density Defects in Silver Nanowires for Enhanced Catalytic Property.

Structural defects have been proven to determine many of the materials' properties. Here, we demonstrate a unique approach to the creation of Ag nanowires with high-density defects through controllable nanoparticles coalescence in one-dimensional pores of mesoporous silica. The density of defects can be easily adjusted by tuning the annealing temperature during synthetic process. The high-density defects promote the adsorption and activation of more reactants on the surface of Ag nanowires during catalytic reactions. As a result, the as-prepared Ag nanowires exhibit enhanced activities in catalyzing dehydrogenative coupling reaction of silane in terms of apparent activation energy and turnover frequency (TOF). We show further that the silane conversion rate can be enhanced by maximizing the defect density and thus the number of active sites on the Ag nanowires, reaching a remarkable TOF of 8288 h(-1), which represents the highest TOF that has been achieved by far on Ag catalysts. This work not only proves the important role of structural defects in catalysis but also provides a new and general strategy for constructing high-density defects in metal catalysts.

Non-Linear Density Dependent Upconversion Luminescence Enhancement of β-NaYF4: Yb3+: Er3+ Nanoparticles on Random Ag Nanowire Aggregates

ABSTRACTSpectroscopic imaging and statistical analysis of NIR-to-visible upconversion luminescence (UCL) from β-NaYF4:Yb3+:Er3+ upconverting nanoparticles (UCNPs) supported on a series of random Ag nanowire aggregates reveals a density dependent UCL enhancement. Statistical analysis of the spectrally resolved upconversion images shows a non-linear dependence of upconversion luminescence enhancement with Ag nanowire surface coverage. A maximum average enhancement of 5.8× was observed for 58% surface coverage. Based on the empirically determined trend with density, it is estimated that up to 20× upconversion luminescence enhancement can be achieved at 100% surface coverage, even at high excitation intensity. This projection is commensurate with the 20× enhancement ratio observed for select locations within the imaged micro-ensemble. Time-resolved emission of the UC luminescence from UCNPs on the Ag nanowire aggregates confirms the surface plasmon effects on the UCNPs kinetics. Such Ag nanowire aggregates show potential as a scalable and relatively simple metal-enhanced upconversion substrate.