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Microfluidics made of dimethylpolysiloxane were developed for chemical synthesis using microwave heating at 24.125 GHz, and microwave efficiency was enhanced by the microwave resonance effect. In addition, the device was fabricated using a mold created using a 3D printer to reduce production costs. The microchip structure comprised a post‐wall waveguide and a microchannel that passed through the waveguide. This post‐wall waveguide also comprises metal columns (post‐wall) instead of a conductor side wall, and easily introduces microchannels through the gaps between the metal columns. The waveguide length was adjusted to achieve a resonance frequency of 24 GHz using an electromagnetic wave simulation, assuming that the microchannel was filled with pure water. Microwaves with an input power of 4 W caused a maximum temperature increase of 93 °C; this result is ~10 °C higher than that of a microchip with non‐resonant structure. In this study, Ag nanoparticles were synthesized using a chemical reaction induced by microwave irradiation of a chip flow system. Owing to irradiating the mixing reagent with microwaves of an input power of 4 W while controlling the flow rate at 0.7 μl/min, the formation of Ag nanoparticles with an average particle size of ~19.2 ± 2.4 nm was demonstrated by absorbance measurements and dynamic light scattering. It is expected that microwave microfluidics enhanced by the resonance effect will substantialize nanoparticle synthesis and high‐efficiency automated chemical synthesis combined with multichemical unit operations. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The trace detection of molecules from highly diluted solutions is critical for biomedical diagnostics, environmental monitoring, food safety, and pharmaceutical quality control. We introduce a highly sensitive superhydrophobic/-philic surface-enhanced Raman scattering (SERS) platform with specific patterns for trace detection. A superhydrophobic structure was fabricated on stainless steel using femtosecond laser-induced periodic surface structures with chemical modification and annealing. The periodic wavy strips, measuring 654 nm in width, are uniformly distributed across a large area. Superhydrophilic patterns of various sizes and shapes were then created on the superhydrophobic surface through nanosecond laser processing. Studying the droplet evaporation process and deposition characteristics shows that target molecules concentrate at the vertex positions of the superhydrophilic pattern, significantly enhancing SERS performance. The triangular pattern with an 800 μm circumcircle diameter exhibited the highest enhancement among the patterns. We demonstrated trace detection of crystal violet mixed with Ag nanoparticles averaging 54 nm in diameter, achieving a Limit of Detection (LOD) of 1.22 × 10–15 M and an enhancement factor of 3.69 × 1010. Furthermore, we integrated our platform with COF@Ag. The COFs display a nearly spherical morphology with an average diameter of 925 nm, and their surfaces are densely and uniformly covered with Ag nanoparticles. This significantly enhances the platform's efficiency in trace detection, enabling the successful detection of the antibiotic amoxicillin with an LOD of 1.01 × 10–11 M. This demonstrates the practical application of the superhydrophobic/-philic SERS platform in biosensing and quantitative analysis, positioning it as a powerful tool for trace detection across various fields. [ABSTRACT FROM AUTHOR]

The objective was to develop an active chitosan‐based coating and to evaluate its effect on the shelf life and microbial safety of bread. Bacterial cellulose nanofibers (BCNF) and various levels (0.5%, 1%, and 2%) of silver nanoparticles (AgNPs) were in the chitosan (CS) film. Characterization of films was determined by analyzing WVP, ultraviolet barrier, and opacity as well as FTIR, XRD, DSC, TGA, and SEM. The water vapor permeability (WVP) of CS was remarkably (p <.05) decreased from 3.75 × 10−10 to 0.85 × 10−10 g/smPa when filled with BCNF and 2% AgNPs. Thermal and structural properties were enhanced in nanoparticle‐included films. Applying CS/BCNF/AgNPs coatings for bread samples demonstrated a significant improvement in moisture retention and a decrease in the hardness (from 10.2 to 7.05 N for CS and CS/BCNF/1% AgNPs coated samples, respectively). Moreover, microbial shelf life of bread sample increased from 5 to 38 days after packaging with CS/BCNF/2% AgNPs film. After a storage period of 15 days at 25°C, no fungal growth was detected in bread samples which were coated with nanocomposite suspensions containing 1% and 2% AgNPs. However, at the same condition, yeast and mold counts was 7.91 log CFU/g for control sample. In conclusion, the CS/BCNF/2% AgNPs film might have the potential for use as active packaging of bread. [ABSTRACT FROM AUTHOR]

Modification of local bamboo‐based catalytic activated carbon with metallic Ag can produce mesopore and micropore types, with a mesopore content of 86%. One of the best ways to reduce formaldehyde concentrations is through catalytic adsorption. In combination with Ag nanoparticle catalyst, formaldehyde adsorption capacity is improved. Adsorption and oxidation reaction experiments are performed in a fixed bed column (di = 10 mm, length = 90 mm). The increase in formaldehyde adsorption associated with the reaction rate of formaldehyde oxidation by metallic Ag is 51 g/mmol. The oxidation reaction of Ag nanoparticles is a bimolecular reaction based on the Langmuir–Hinshelwood mechanism. Formaldehyde can be reduced by 59% and 41% through the role of adsorption and support of catalytic oxidation, respectively. Additionally, harmless gases such as CO2 and H2O are produced within the column. [ABSTRACT FROM AUTHOR]

In order to exert the synergistic photocatalytic effect of nano-noble metal and polymer matrix, hexagonal boron nitride nanosheets (h-BNNS) were doped with C and O elements by RGO to obtain porous doped boron nitride materials (BCNO), and silver nanoparticles (Ag NPs) were loaded on BCNO matrix by hydrothermal method to prepare BCNO/Ag composites. The composition, microstructure and photocatalytic properties of the composites were characterized. The photocatalytic properties of BCNO/Ag composites were tested by reducing CO2 to CO as a reaction model. The results show that boron nitride modified by nonmetal doping still has a stable polycrystalline structure; After loading Ag NPs, the plasma resonance effect of Ag NPs not only significantly enhances the absorption ability of BCNO matrix to ultraviolet-visible light, but also improves the separation efficiency of its photogenerated carriers; During the preparation of composite materials, the composite material obtained with the addition of 3.0% silver and the calcination temperature of the composite sample at 130 ℃ exhibits the best photocatalytic performance, and the conversion rate of CO2 to CO is 4.68 μmol/（g·h）. Therefore, h-BNNS modified by doping can better stably load nano-precious metals, thus giving full play to the synergistic photocatalytic performance of Ag nanoparticle and BCNO, which provides a theoretical basis for the effective composite and performance research of organic-inorganic nanophotocatalyst.

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, green synthesis of silver nanoparticles (VNE-AgNPs) via Verbascum nudatum extract was carried out for the first time. The synthesized AgNPs were characterized by different spectral methods such as UV–vis, FTIR, XRD, TEM, and EDAX. According to TEM analyses, the average size range of AgNPs was 17–21 nm, and the dominant peaks in the 111°, 200°, 221°, and 311° planes in the XRD pattern indicated the Ag-NPs FCC crystal structure. FTIR data showed that VNE-AgNPs interacted with many reducing, capping, and stabilizing phytochemicals during green synthesis. VNE-AgNPs had higher antibacterial activity against S. aureus and E. coli bacterial strains with a maximum inhibition zone of 21 and 18 mm, respectively, than penicillin 5 IU, used as a positive control in the study. The cytotoxic effect of VNE-AgNPs appeared at a concentration of 50 µg/mL in L929 cells and 5 µg/mL in cancer (A549) cells. When the impact of VNE-AgNPs and C-AgNPs on inflammation was compared, it was found that VNE-AgNPs increased TNF-α levels (333.45 ± 67.20 ng/mg-protein) statistically (p < 0.05) more than TNF-α levels (256.92 ± 27.88 ng/mg-protein) in cells treated with C-AgNPs. VNE-Ag-NPs were found to have a degradation efficiency of 65% against methylene blue (MB) dye within 3 h. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Single-element phosphorus is an emerging class of two-dimensional (2D) semiconductor materials that has attracted extensive attention, particularly as a photocatalyst material. However, the inherent instability of elemental phosphorus causes insufficient surface activity for photocatalytic performance. In this study, the self-adsorption and clustering of metal ions on the surface of 2D materials were exploited to form Ag nanoparticle (NP)-modified black phosphorus (BP-Ag) heterostructures, which passivated the lone-pair electrons of phosphorus, promoted charge separation, and enhanced the photocatalytic activity. Consequently, the photocatalytic decomposition of methyl orange with BP-Ag was 99.05%, which was 1.87 times higher than that of pure black phosphorus. Within 3 h, the photocatalytic hydrogen evolution efficiency of BP modified by Ag NPs was about 20 times that of BP. In addition, the decomposition of dye molecules was investigated using active substances, such as hydroxyl radicals, superoxide radicals, and holes. In conclusion, the modification of metal NPs can greatly improve the stability and photocatalytic performance of single-element phosphorus materials, which has good application prospects for purifying dye wastewater and hydrogen evolution. [ABSTRACT FROM AUTHOR]

The emergence of fluorinated organic compounds in the pharmaceutical, agrochemical, and textile industries has led to a potential increase in the environmental issues and health problems. Herein, a modified heterojunction of bio-synthesized Ag nanoparticles (Ag0 NPs) immobilized on imidazole-modified graphite carbon nitride (Im/g-C3N4) as a suitable support (Ag0/Im/g-C3N4) was hydrothermally synthesized and studied for the photocatalytic removal of the most widely used antifungal organo-fluorine compound—fluconazole (FCZ). The optical properties were thoroughly investigated in the present study, and it was observed that the proposed modification to g-C3N4 has led to the shifting of conduction and valance band edge position (for g-C3N4, −0.73 and 1.54 eV and for ICA, −1.14 and 1.28 eV), narrowing of band gap energies, i.e., 2.01 eV, and reduced charge recombination rate. The external and internal surface morphologies were scrutinized through FE-SEM and HR-TEM analyses. Functionalities and potential crystallinity were investigated using FTIR and XRD techniques. The elemental state and composition of the composite were analyzed via XPS. The obtained results substantiate the intended modifications in the ICA composite. The photocatalyst Ag0/Im/g-C3N4 (ICA) was able to degrade 95.74% of FCZ with a high degradation rate (k1) of 0.0289 min−1 within 2-h of the solar illumination experiment. The overall degradation process was observed to be governed by a pseudo-first-order kinetic model. Detailed parameters such as effects of ions, pH (optimized pH 4, highest degradation rate k1 =0.039 min−1), dissolved organic matter (DOM), and optimization of catalysts dosage were studied. The major reactive oxygen species (ROS) was identified as super-oxide radicals (O2●−). The HR-MS and COD-TOC analysis were used to evaluate the degradation and mineralization of FCZ forced by ICA catalysts. The ICA catalyst was found to be stable and reusable for up to five cycles suggesting towards its potential towards the mitigation of environmental pollutants. [ABSTRACT FROM AUTHOR]

In recent years, Ag nanoparticle (Ag NP)-loaded antibacterial dressings have attracted much attention in high-level medical dressings. However, the high cytotoxicity of Ag NP has always been a problem. In this paper, we examined the improvement of antibacterial activity of berberine hydrochloride (BBR) with Ag NP, the results showed that the combined use of BBR and Ag NP can effectively reduce the dosage of Ag NP while ensuring the inhibition of bacterial growth, thus an intermediate layer dressing containing combined drugs were prepared. At the same time, the top dressing of polyvinyl alcohol (PVA) solid film and the PVA bottom dressings with three kinds of leakage structures were prepared by 3D printing technology. Three kinds of PVA bottom dressings showed high quality consistency, and the greater the number of leak holes, the higher the porosity value of the dressing, while the swelling ratio value of the bottom layer dressing with three holes was the lowest. Finally, three types of BBR-Ag NP composite antibacterial dressings (3D-BBR-Ag NP) can be obtained by self-assembling of the top dressing, the intermediate layer dressing, and the bottom dressings with three kinds of leakage structures. The cumulative drug release results showed that dressing with more holes had a faster drug release rate compared to the other two ones with fewer leakage holes. Besides, five drug release kinetic models were used to investigate the cumulative BBR release profiles for three types of 3D-BBR-Ag NP. And the three types of composite dressings showed strong antibacterial activity after 6 h of cultivation with staphylococcus aureus. The study showed that the antibacterial activity of the self-assembled dressing prepared by combination of BBR with Ag NP can be improved, and the drug release rate of the hydrogel dressing can be flexibly controlled through 3D printing technology. [ABSTRACT FROM AUTHOR]

In order to improve the property of polyacrylonitrile (PAN) nanofibrous membrane, MgO nanoparticles and Ag nanoparticles (MgONPs and AgNPs) were added into the polyacrylonitrile (PAN) solution. PAN/MgO/Ag composite nanofibrous filtration membranes with different mass fractions of MgO and Ag nanoparticles were prepared through electrospinning method. Their microstructure, crystalline structure, air permeability, moisture permeability and filtration property were tested by scanning electron microscope, X-ray diffractometer, infrared spectrometer, ultraviolet translucency analyzer and filtration property tester. Test results showed that the fiber diameter of pure PAN nanofiber was 222.9 nm while the diameter of PAN/MgO/Ag composite nanofibers were 151.5 nm~258.6 nm. Compared with pure PAN nanofibrous membrane, composite PAN/MgO/Ag nanofibrous membranes possessed excellent filter performance and ultraviolet protective property. Their UV protective factor were 38.73~55.37. The filtration efficiency were 95.36%~97.59% while the pressure drop were 46.06 Pa~58.31 Pa. When the mass fraction of MgONPs and AgNPs were both 0.75%, PAN/MgO/Ag composite nanofibrous membrane had the maximum quality factor of 0.071 4 Pa-1 and the filtration performance was the best, which belonged to the fiber filtration material with higher efficiency and lower resistance and UV protection property. [ABSTRACT FROM AUTHOR]

Catechol formaldehyde resin microspheres with surface-distributed silver nanoparticles (Ag@CFR microspheres) were synthesized and then used as functional additives to fabricate antimicrobial viscose fibers (Ag@CFR/viscose fibers) through the wet spinning method. Ag@CFR microspheres showed high broad-spectrum antibacterial properties and presented low cytotoxicity on mammalian cells. With 0.1, 0.3, and 0.5 wt% additions of Ag@CFR microspheres in the viscose solution, all the viscose spinning solutions exhibited a little change in the viscosity and showed long-term stability without any sedimentation of the particles. With only 0.5 wt% additions of Ag@CFR microspheres, Ag@CFR/viscose fibers achieved high antimicrobial activities and severally presented a bacteriostasis and fungistatic rate of 99.6%, 99.4%, and 92.7% against E. coli, S. aureus, and C. albicans. Ag@CFR microspheres had very little influence on the mechanical and moisture absorption performance of the fiber. This work can provide an approach for the large-scale production of antibacterial viscose fibers and widen the application of Ag NPs in high-quality functional regenerated cellulose fibers. [ABSTRACT FROM AUTHOR]

Porous polymeric frameworks have received great interest over the past few years because of their nonstop growth as crystalline porous polymeric materials connected through covalent bonds and versatile utilities in diverse fields. The production of high-value organic compounds via sustainable and environment-friendly methods is an uphill struggle for researchers. The elegant strategy of using carbon dioxide as a C1 building block is an intriguing platform owing to its non-toxicity, easy accessibility, natural abundance, recyclability, non-flammability, and cheapness. Additionally, CO2 levels are regarded as the main contributor to the greenhouse effect (the most abundant greenhouse gas across the globe) and the aforementioned strategy needs to mitigate CO2 emissions. This present study describes the synthesis of silver nanoparticles (AgNPs) embedded in a porous polymeric framework, a reusable heterogeneous catalyst (recyclable over 5 times), TpMA (MC)@Ag. The synthesized catalyst is characterized by using FT-IR, PXRD, XPS, FE-SEM, TEM, EDAX, TGA DTA, and N2 sorption studies. Additionally, the catalysts can be easily recycled to generate the desired α-alkylidene cyclic carbonates and oxazolidinone compounds under solvent-free conditions. This research demonstrates the potential of nanoporous 2D porous polymeric framework-based materials in the area of catalysis, specially, in CO2 capture and chemical fixation. These findings offer a promising approach for the chemical fixation of CO2 into α-alkylidene cyclic carbonates and oxazolidinones from propargylic alcohols utilizing AgNPs embedded in a 2D catalyst, which functions as a potential heterogeneous catalyst under mild conditions (e.g., solvent-free approach). [ABSTRACT FROM AUTHOR]

Owing to their degradability, environmental friendliness, and low cost, natural polymers have been widely utilized in the fabrication of triboelectric nanogenerators (TENGs). Chitosan is a natural polymer containing long chains of n-acetylamino glucose. However, the low dielectric constant of pure chitosan films affects their electrical properties. Therefore, in this study, to improve their electrical output performance, the dielectric constant of the films was increased by the incorporation of conductive nanoparticles. Highly transparent Ag/Chitosan films were successfully constructed, and the output performance was improved by varying the concentration of Ag nanoparticles (100–200 nm). At a concentration of 6 wt %, the open-circuit voltage, short-circuit current, and transferred charge reached 74 V, 4.6 μA, and 23.8 nC, respectively, with a maximum output power of 83 μW. Besides, the fabricated friction-based nanogenerator (AC-TENG) lit 20 blue light-emitting diodes (LEDs) and successfully drove a commercial calculator, which verified its practical application potential. Finally, the AC-TENG was used to transmit Morse code, successfully sending the signals "HELP" and "SOS", which might open opportunities in the field of communication application. [ABSTRACT FROM AUTHOR]

Due to the strong oxidizing properties of H2O2, excessive discharge of H2O2 will cause great harm to the environment. Moreover, H2O2 is also an energetic material used as fuel, with specific attention given to its safety. Therefore, it is of great importance to explore and prepare good sensitive materials for the detection of H2O2 with a low detection limit and high selectivity. In this work, a kind of hydrogen peroxide electrochemical sensor has been fabricated. That is, polypyrrole (PPy) has been electropolymerized on the glass carbon electrode (GCE), and then Ag and Cu nanoparticles are modified together on the surface of polypyrrole by electrodeposition. SEM analysis shows that Cu and Ag nanoparticles are uniformly deposited on the surface of PPy. Electrochemical characterization results display that the sensor has a good response to H2O2 with two linear intervals. The first linear range is 0.1–1 mM (R2 = 0.9978, S = 265.06 μA/ (mM × cm2)), and the detection limit is 0.027 μM (S/N = 3). The second linear range is 1–35 mM (R2 = 0.9969, 445.78 μA/ (mM × cm2)), corresponding to 0.063 μM of detection limit (S/N = 3). The sensor reveals good reproducibility (σ = 2.104), repeatability (σ = 2.027), anti-interference, and stability. The recoveries of the electrode are 99.84–103.00% (for 0.1–1 mM of linear range) and 98.65–104.80% (for 1–35 mM linear range). Furthermore, the costs of the hydrogen peroxide electrochemical sensor proposed in this work are reduced largely by using non-precious metals without degradation of the sensing performance of H2O2. This study provides a facile way to develop nanocomposite electrochemical sensors. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) has been used as a precursor for the preparation of surface-enhanced Raman scattering (SERS) substrates because of its ability to act as a reducing agent and binding site of plasmonic metal nanoparticles (NPs). However, the processability of PANI is limited due to its poor mechanical properties. In this work, a simple preparation of a free-standing polymeric blend film by mixing hydrochloric acid–doped polyaniline nanofibers (PANI) and cellulose acetate (CA) is demonstrated. This PANI/CA was used as a reducing agent for synthesizing Ag nanoparticles (AgNPs). The formation of globular NPs and cubic microstructures on the surface of the film was observed, as well as the formation of AgCl due to the presence of chloride ions in the PANI structure. The film was then treated with hydrazine to reduce AgCl to AgNPs resulting in isolated and clustered AgNPs. Rhodamine 6G dye was used as a probe molecule for SERS measurements. This new composite film PANI/CA@Ag treated with hydrazine was successfully applied as a SERS substrate. This substrate enhancement of Rhodamine 6G dye Raman bands was estimated, and the Rhodamine 6G dye could be detected even at a concentration of 10−7 mol L−1. [ABSTRACT FROM AUTHOR]

MnO 2 is considered to be one of the most promising electrocatalysts for oxygen reduction reactions (ORR) in alkaline media and can be applied to various electrochemical energy conversion and storage devices. However, it is limited by the relatively slow kinetics of the cathodic electrochemical reactions. In addition, it is difficult to control the presence state of Ag during the modification of MnO 2. To this end, an efficient ORR electrocatalyst of Ag nanoparticles supported by MnO 2 nanorods was successfully synthesized by using NH 3 ·H 2 O as a complexing agent to inhibit the Ag+ intercalating into the tunnels of MnO 2. The half-wave potential (E 1/2) and limiting current density (J lim) of the obtained Ag/MnO 2 electrocatalysts are 0.81 V and −5.6 mA cm−2, respectively, showing comparable ORR catalytic activity to commercial Pt/C catalysts. The excellent catalytic performances can be attributed to the presence of abundant oxygen vacancies and Mn3+ species on the MnO 2 surface, as well as the synergistic effect between MnO 2 substrates and Ag nanoparticles. Among them, oxygen vacancies enhances the adsorption of O 2 , Mn3+ facilitates the displacement of O 2 2−/OH−, MnO 2 inhibits the accumulation of peroxide species to improving the oxygen environment on the Ag surface and Ag accelerates the electron transfer in the whole process. This work provides a useful guide for the design of efficient Mn-based ORR electrocatalysts. [Display omitted] • NH 3 ·H 2 O inhibits the diffusion of Ag+ and facilitates the synthesis of Ag/MnO 2. • The excellent activity is due to the synergistic effect between MnO 2 and Ag. • O V improves the O 2 adsorption and Mn3+ facilitates the O 2 2−/OH− displacement. • A green and efficient way was adopted to the scale synthesis of ORR catalyst. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) has attracted tremendous attention in the field of photocatalytic CO2 conversion due to excellent optical character and carrier separation efficiency. However, photocatalytic CO2 conversion is a multiple proton-coupled electron transfer process that usually produces various products, and it is still a major challenge for improving the yield and selectivity of CO2 to a single product. Herein, a low-temperature deposition method combined with the dynamic hydrogen bubble template method was used to synthesize a Ag/Cu2O photocatalyst to tackle this problem. The Ag/Cu2O photocatalyst has porous nanostructures and exhibits excellent performance in photocatalytic CO2 reduction. The CO yield of Ag/Cu2O-0.04 is 22.52 nmol cm–2 h–1 (43.04 μmol g–1 h–1), which is about 1.5 times that of the original sample. For the selectivity of CO, Ag/Cu2O was increased by 22% compared with Cu2O, reaching 82.9%. Combined with density functional theory and Fourier transform infrared spectroscopy, it is found that Ag loading changes the adsorption configuration of CO2 on the catalyst from bidentate carbonate to monodentate carbonate, improving the selectivity of CO. In addition, the Ag/Cu2O Schottky junction accelerates the surface reaction kinetics due to acceleration of the separation and transportation of photogenerated carriers. Therefore, this work provides an idea to develop a high-efficient photocatalyst for photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

In this paper, nanoparticles of silver, copper, and iron were prepared by biological green synthesis method by herbal extracts of pomegranate leaves, dry powder of oak fruit, pistachio skin, and green tea as chemical reduction agents. The structural, optical, and antibacterial properties of silver, copper, and iron nanoparticles against Gram-negative bacteria K. pneumonia, S. enteritidis, E. coli, and Gram-positive B. cereus and S. aureus were investigated. The crystal structure and particle distribution of the prepared nanoparticles were studied by XRD and SEM analysis. The optical absorption and band gap of silver, copper, and iron nanoparticles prepared with plant extracts were determined by ultraviolet–visible spectroscopy (UV–Vis). To know the presence of organic substances in the synthesized nanoparticles, the absorption spectrum in the infrared region was investigated using a Fourier transform infrared spectroscopy (FTIR). The results of the XRD analysis show the formation of the structure of the face center cubic (fcc) for silver and copper nanoparticles and structure of the body center cubic (bcc) for iron nanoparticle. In addition, the obtained XRD analysis shows that the average size of prepared silver, copper, and iron nanoparticles is 26.5, 24.6, and 45.0 nm, respectively. Our calculations show that the band gap of silver, copper, and iron metal nanoparticles is between 1.3–1.4 eV, 2.15 eV and 1.46 eV, respectively. The silver and copper nanoparticles have good antimicrobial properties in low concentrations against Gram-negative bacteria E. coli. [ABSTRACT FROM AUTHOR]

Silver nanocatalyst (40 wt%) is deposited on commercial mesoporous carbon support material (Ag/C) using two different wet chemical methods, to obtain high electrochemically active surface area. The catalyst materials are characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermogravimetric analysis and are evaluated toward the oxygen reduction reaction (ORR) in alkaline media employing the rotating disk electrode method. It is worth noting that the Ag/C leads to oxygen reduction through a direct four-electron pathway in alkaline medium. The silver catalyst on mesoporous carbon exhibits relatively higher mass activity for ORR (38 A g−1) compared to that with Vulcan carbon (32 A g−1) at −0.2 V vs SCE at room temperature. Anion exchange membrane fuel cell shows maximum power density of 310 mW cm−2 with Ag/C cathode catalyst using H 2 and O 2 gases at 65% RH conditions at 65 °C. [Display omitted] • 40 wt% Ag/C catalysts were prepared onto novel mesoporous engineered carbon supports. • ORR on the synthesized Ag-based catalyst materials follows a four-electron pathway. • Mass activity for ORR on Ag/C catalysts surpassed that of Ag/VC. • Peak power density of 310 mW cm−2 with Ag/C cathode was obtained in AEMFC test. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) spectroscopy has attracted increasing attention due to its high spectral reproducibility and unique selectivity to target molecules. Here, a facile approach is proposed to prepare Ag nanoparticles modified ZnO nanorod arrays (Ag/ZnO NR arrays). Ag nanoparticles were densely decorated on the surface of ZnO nanorods through silver mirror reaction and subsequent seed-assisted electrodeposition. The prepared Ag/ZnO NR arrays can be used as a sensitive, uniform, and repeatable SERS substrate for the rapid detection of organic dye molecules and biomolecules with concentrations higher than the corresponding limits of detection (LODs). The LODs for rhodamine 6G (R6G), 4-aminothiophenol (PATP) and adenine are calculated to be 1.0 × 10−13 M, 1.6 × 10−12 M and 3 × 10−11 M, respectively. The enhancement factor (EF) of the SERS substrate is estimated to be as high as ~2.7 × 108 when detecting 10−10 M R6G. Particularly, the as-synthesized substrate exhibits high selectivity to multiple components. In addition, the fabricated Ag/ZnO NR arrays can be recycled due to their superior self-cleaning ability and can realize photocatalytic degradation of R6G in water within 1 h driven by UV light, showing that the three-dimensional recyclable SERS substrates have wide applications in environmental pollution monitoring and biomedical analysis. [ABSTRACT FROM AUTHOR]

Ag plasmonic nanoparticles have been produced depending on laser pulse energy by applying pulsed laser deposition technique. Localized surface plasmon resonance (LSPR) peak of silver (Ag) plasmonic nanoparticles has been shifted towards longer wavelength region by increasing laser energy. By embedding Ag nanoparticles into copper zinc tin sulphide (CZTS) ultrathin film, the crystal structure of CZTS ultrathin film has been improved somewhat and its band gap has been decreased. CZTS and (Ag) plasmonic CZTS/n-Si heterojunction solar cells have been produced and their J–V characteristics have been obtained for darkness and light environments. The parameters of heterojunctions such as barrier height, ideality factor and serial resistance have been calculated under dark environment by applying the conventional J–V and Norde and Cheung–Cheung methods and found to be partially compatible with each other. The photocurrent, Jsc, open circuit voltage, Voc, and thus, η values for plasmonic CZTS solar cell have been increased, as hot electron formation occurred in CZTS ultrathin film due to LSPR property of Ag nanoparticles. In addition, the photovoltaic parameters of non-plasmonic and plasmonic CZTS solar cells have been calculated by SCAPS-1D simulation; thus, the experimental and calculated parameters have been compared and found to be compatible with each other. [ABSTRACT FROM AUTHOR]

Surgical sutures are one of the most widely used medical devices for wound closure. In the meantime, the suture surface and area may be exposed to many microorganisms, and surgical site infections may develop in these environments. Today, giving antimicrobial properties to polymeric sutures has been one of the methods used to prevent these infections. In this study, the absorbable polymeric-based suture (Pegelak®) was homogeneously coated with nano-sized silver particles by the vacuum deposition at the cryogenic temperatures (< 300 K) instead of the commonly used vacuum deposition at high substrate temperatures, and its physical and antibacterial properties were investigated. It was determined from the morphological and tensile strength analysis that some deformations occurred in the Ag-coated suture at 300 K; however, the coating of the suture at 200 K did not significantly affect the morphological and mechanical properties of the suture. According to photocurrent measurement, the plasmon resonance effect of the Ag-nanoparticles-coated suture at 200 K was observed around 450–525 nm. The illumination of the Ag-coated suture at 200 K with light in the plasmon resonance wavelength region increased the Ag+ release from 3.67 × 10−3 ppm to 6.65 × 10−3 ppm. In the microbiological analysis, it was observed that Ag-coated sutures obtained at both 200 K and 300 K showed antibacterial activity against all tested bacteria. [ABSTRACT FROM AUTHOR]

The γ-Al2O3 support (nanosphere and nanoflake) was used to support Ag nanoparticles and applied in C3H8-SCR to remove NOx. Ag/Al2O3-flake exhibited superior catalytic activity than Ag/Al2O3-sphere in C3H8-SCR. It is found that Al2O3-flake rich in Al octacoordinated ions promoted more Agnδ+ species to disperse on Ag/Al2O3-flake than Ag/Al2O3-sphere. Agnδ+ species could strengthen the low-temperature catalytic activity for HC-SCR while Ag metal particles were unbeneficial since they could promote complete oxidation of hydrocarbon. This was the first time to explore the remarkable effect of Al2O3 intrinsic properties on catalytic activity of alumina-supported catalyst for HC-SCR from the perspective of uniform morphology. Environmental implication: The number of transport vehicles has increased dramatically during the past decades due to global economic growth. The accompanying concern is the huge consumption of fossil fuels, for example, gasoline and diesel, which speeds up global warming. Internal combustion engines produce toxic emissions, where NOx forms nitric acid in the atmosphere, reacts with HCs to form which causes acidification of land and lakes. Currently, it is urgent to develop a leading deNOx technique for the after-treatment of commercial engine-powered vehicles to meet stringent emission legislations.

Battery-type electrode materials have attracted much attention as efficient and unique types of materials for hybrid battery supercapacitors due to their multiple redox states and excellent electrical conductivity. Designing composites with high chemical and electrochemical stabilities is beneficial for improving the energy storage capability of battery-type electrode materials. We report on an interfacial engineering strategy to improve the energy storage performance of a Co(OH)2-based battery-type material by constructing polypyrrole-assisted and Ag-doped (Ag-doped@Co(OH)2@polypyrrole) nanosheets (NSs) on a Ni foam using a hydrothermal process that provides richer electroactive sites, efficient charge transportation, and an excellent mechanical stability. Physical characterization results revealed that the subsequent decoration of Ag nanoparticles on Co(OH)2 nanoparticles offered an efficient electrical conductivity as well as a reduced interface adsorption energy of OH- in Co(OH)2 nanoparticles as compared to Co(OH)2@polypyrrole-assisted nanoparticles without Ag particles. The heterogeneous interface of the Ag-doped@Co(OH)2@polypyrrole composite exhibited a high specific capacity of 291.2 mAh g−1 at a current density of 2 A g−1, and showed a good cycling stability after 5000 cycles at 5 A g−1. The specific capacity of the doped electrode was enhanced approximately two-fold compared to that of the pure electrode. Thus, the fabricated Ag-doped@Co(OH)2@polypyrrole nanostructured electrodes can be a potential candidate for fabricating low-cost and high-performance energy storage supercapacitor devices. [ABSTRACT FROM AUTHOR]

Flexible surface-enhanced Raman spectroscopy (SERS) substrates were produced by in situ chemical reduction of Ag+ on poly(vinyl alcohol)/chitosan (PVA/CS) nanofibers. PVA/CS nanofibers (which have a large number of amino and hydroxyl functional groups) were prepared by electrospinning, which can provide more sites for adsorbing Ag+ than pure PVA. The Ag nanoparticles were evenly distributed on the PVA/CS nanofibers. The SERS substrate also exhibited excellent water stability, sensitivity, and uniformity. The detection limit of probe molecule rhodamine 6G was 10−7 M and the relative standard deviation was 5%. In addition, the Ag–PVA/CS nanofibers substrate was effective for recognition and detection of norfloxacin, a well-known antibiotic that is pertinent to food safety and animal/human health. [ABSTRACT FROM AUTHOR]

The surface-enhanced Raman scattering (SERS) technique provides a quick and reliable method for detecting pesticide residues. In this study, flexible substrates, composed of orderly arranged silver nanospheres (Ag NPs) films on graphene paper, were fabricated through a simple, low-cost Ag NP self-assembly process at a liquid-liquid interface, followed by transfer of the films onto the graphene paper. The SERS performance of the fabricated substrates was evaluated using a portable Raman spectrometer, with rhodamine 6G (R6G) serving as the probe molecule. The results indicate that the bilayer Ag NP films-covered graphene paper exhibits optimal overall performance, characterized by high sensitivity and high uniformity. The limit of detection (LOD) for the R6G molecule is as low as 8.73 × 10 -9  M, demonstrating the strong signal amplification capability of the SERS substrate. Moreover, the relative standard deviation (RSD) of the Raman intensity at 1508 cm -1 for different selected points on the substrate is 5.018 %, indicating high uniformity of the SERS substrate. Finally, the performance of the SERS substrate was further evaluated by detecting thiram in fresh orange juice, demonstrating the capability to detect concentrations as low as 10 -6  M. This result highlights the significant potential of the developed SERS substrate for practical applications in food safety and quality control., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The development of efficient, economical and stable oxygen reduction reaction (ORR) electro-catalysts is crucial to energy storage-conversion technology. Reducing metal dimension to nanosize is a promising approach to maximize its efficiency, whereas the migration and aggregation of nanoparticles have severely hampered their large-scale applications. Herein, we report a new catalyst of N-doped carbon-coated Ag nano-particles (Ag NP@N-C), wherein Ag nanoparticles are confined by N-doped carbon framework. This as-synthesized Ag NP@N-C exhibits excellent ORR performance with a half-wave potential of 0.83 V and a limit-current density of 7.03 mA cm−2 in an alkaline medium. More importantly, its durability (cycling for 3600 min), methanol resistance ability in alkaline solutions and catalytic properties in rechargeable zinc-air battery outperform those of commercial Pt/C catalyst and other similar Ag-based catalysts reported so far. The main reason stems from the fact that the interaction between Ag nanoparticles and the support of N-doped carbon can be enhanced by the co-work of pyridine nitrogen and carbon vacancy, rationalizing uniform dispersion of Ag particles. Taking into account its simplicity and high electrochemical properties, we believe that spatial confinement might take an effective trajectory to develop new and large-scale catalysts.

Ag nanoparticles are a promising additive for enhancing the thermal conductivity of PCMs. In this study, a series high thermal conductive shape-stable composite phase change materials PCMs were prepared by absorbing the Paraffin (PW) into the Ag nanoparticles modified expanded graphite (Ag@EG). SEM and EDS results proved that Ag nanoparticles were uniformly modified onto EG. The XPS results for Ag@EG indicated that the valence state of Ag in the EG was mainly zero. The XRD and FT-IR results of Ag@EG/PW indicated that the composite PCMs (CPCMs) have good chemical compatibility. The PW capacity in all CPCMs reached upon 60% with the latent heat in the range of 124.4–112.2 J/g. The thermal conductivity of 3.9-AEP reached 3.98 W/m/K which was enhanced by 1890.0% and 170.3% compared with PW and 0-AEP, respectively. All CPCMs possessed good thermal stability and thermal reliability after 200 thermal cycles. This indicated that the form-stable composite PCMs of Ag@EG/PW were good candidate materials for thermal energy storage in solar energy storage systems. [ABSTRACT FROM AUTHOR]

Revealing the charge transfer path is very important for studying the photocatalytic mechanism and improving photocatalytic performance. In this work, the charge transfer path turned by the piezoelectricity in Ag-BaTiO3 nanofibers is discussed through degrading methyl orange. The piezo-photocatalytic degradation rate of Ag-BaTiO3 is much higher than the photocatalysis of Ag-BaTiO3 and piezo-photocatalysis of BaTiO3, implying the coupling effect between Ag nanoparticle-induced localized surface plasmon resonance (LSPR), photoexcited electron-hole pairs, and deformation-induced piezoelectric field. With the distribution density of Ag nanoparticles doubling, the LSPR field increases by one order of magnitude. Combined with charge separation driven by the piezoelectric field, more electrons in BaTiO3 nanofibers are excited by plasmon-induced resonance energy transfer to improve the photocatalytic property. [ABSTRACT FROM AUTHOR]

A poly(vinyl pyrrolidone) (PVP)/Ag nanoparticles (AgNPs)/7,7,8,8-Tetracyanoquinodimethane (TCNQ)/dioctyl phthalate (DOP) composite membrane using positively charged silver nanoparticles was prepared for CO2 separation. Positively polarized silver nanoparticles were generated by TCNQ, known as an electron acceptor for CO2 carrier. In the separation of CO2 and N2, the composite membrane consisting of PVP/AgNPs/TCNQ/DOP showed that only polar CO2 could be selectively separated by a reversible reaction with the positively polarized silver nanoparticles. Furthermore, the addition of DOP as a plasticizer enhanced gas permeance through the glassy PVP, and the CO2/N2 selectivity performance reached 103.8. The PVP/AgNPs/TCNQ/DOP composite membranes were characterized by FTIR spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

Supramolecular chirality arising from periodic asymmetrical packings of building units plays a significant role in development of smart chiral materials, but the thorough mechanism of chirality control on self-assembly has seldom been understood. Here, three isomeric amphiphiles p/m/o-Py-BL (para/meta/ortho-pyridine-appended betulin) were synthesized from a natural pentacyclic triterpenoid. The presence or absence of supramolecular chirality of assembled p/m/o-Py-BL was regulated by isomeric effects, determined by conformation and strength of intramolecular H-bonds. The helical topologic transformation and chiroptical activity transitions modulated by Ag+ were also reported, ascribed to the transformed conformation of building units, converting a network of chiral nanofibers into helical nanoribbons. In addition, the helical nanoribbons of p-Py-BL/Ag+ were capable of in situ synthesis of Ag nanoparticles with plasmonic chirality. These findings provided a blueprint for regulating supramolecular handedness by isomerism and metal ions, affording a deeper understanding on chiral self-assembly processes and facilitating the applications of triterpenoid-based assemblies in chiral nanomaterials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polyindole (PIn) is applied in the humidity sensor field for the first time. • Doping of Ag nanoparticles improves the electrical conductivity of polyindole and increases the reactive surface area. • HEC provides more active sites and increases the humidity response of the sensor. • The Ag-PIn/HEC sensor has great potential for non-contact sensing, respiratory monitoring and speech recognition. A highly sensitive humidity sensor based on Ag doped polyindole/hydroxyethyl cellulose (Ag-PIn/HEC) composite is constructed for relative humidity sensing at room temperature in this study. Doping of Ag and HClO 4 is used to solve the problem of poor electrical conductivity of polyindole (PIn). The humidity sensitive material is prepared by the combination of HEC binder and doped PIn, which realizes the high sensitivity humidity detection. The Ag-PIn/HEC sensor showed high response value (93800 %), good linearity (R2 = 0.993), fast response time (8 s), low humidity hysteresis (4.16 %), good reproducibility, and stability over a detection range of 11 ∼ 84 % relative humidity (RH). In addition, the humidity sensor has a specific response to human breath. According to the change of impedance signals, it can easily distinguish between oral and nasal breathing as well as light or rapid breathing, which can be used in medical care, such as preventive monitoring for special groups (asthma patients). Moreover, the sensor can recognize certain simple words by detecting changes in exhalation while speaking, which provides potential applications in speech recognition and non-contact switches. [ABSTRACT FROM AUTHOR]

A composite film composed of Ag nanoparticles, Al2O3 and TiO2 was prepared by cosputtering. Ag NPs were immersed in the Al2O3 host, TiO2 was deposited onto the Ag/Al2O3 layer. The degradation of aqueous methylene blue under incident irradiation indicated that the Ag/Al2O3-TiO2 composite film with the Ag-TiO2 distance of 2nm or 5nm exhibited high degradation rate. Spectral absorptivity and radiant absorption distribution were analyzed through FDTD simulation to analyze the relationship between radiant absorption and photocatalytic activity. Results indicated that the spectrum and distribution of the radiant absorption in the composite film could be rationally regulated to improve photocatalytic activity.

[Display omitted] • Fabrication of plastic compatible transparent conductor (TC) with silver (Ag) nanostructure. • Growth mechanism of percolated Ag nanostructure associated with TC deposition. • Fabricated hot-electron photodetector using Ag nanostructure based TC. • Utilization of plasmonic hot-electron for photocurrent generation of a photodetector. • Fabrication of hot-electron photodetector with high detectivity and fast response speed. A percolated silver (Ag) nanostructured-based transparent conductor has been deposited by physical vapor deposition (PVD) technique where lateral growth of Ag has been enhanced by a pre-deposited Ag-TiO 2 thin film. This Ag-TiO 2 film has embedded Ag nanoparticles (NPs) within TiO 2 thin film which is grown in a low temperature (100 °C) solution processed technique. This process includes Li 4 Ti 5 O 12 (LTO) thin film deposition by a sol–gel method followed by ion-exchange (Li+ → Ag+) process to yield an Ag-TiO 2 thin film. The percolated Ag network has appeared as soon film mass-thickness reaches close to 10 nm, resulting in an abrupt drop of electrical resistivity of the film. This percolated Ag nanostructured thin film (10 nm Ag/Ag-TiO 2 /plastic) has resistivity of ∼50 Ω/□ and an average visual transmittance of >70 % up to 450 nm. In higher wavelength range, transparency gradually reduces, and it reaches to ∼50 % at 600 nm which is mostly due to the plasmon absorption of this film. By utilizing its combined optical transparency and surface plasmon absorption, this film has been used to develop plasmonic hot electron photodetectors where Ag-thin film works as transparent electrode as well as plasmon induced photo-excited hot electron generation. Device has been fabricated on a heavily doped n type Si (n++-Si) with a metal–semiconductor-metal (M−S−M) device geometry. External quantum efficiency (EQE) data reveal that photocurrent of this device is mostly generated in the plasmonic absorption region with a peak detectivity of 2.84 × 1012 Jones at 510 nm under −3V external bias. Besides, the device shows fast response with a response time of ∼25 ms. [ABSTRACT FROM AUTHOR]

In this paper, a facial strategy is employed to directly growing ZnO nanorods (ZnONR) on carbon fiber paper (CFP) and functionalizing with silver nanoparticles (AgNP), constructing a structural stable paper-based electrode (AgNP/ZnONR@CFP). This unique AgNP/ZnONR hierarchical nanoarchitecture provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards flavonoids oxidation. When the electrode is evaluated as a binder-free sensor for flavonoids detection, three distinct and separate differential pulse voltammetric peaks for luteolin, daidzein, and baicalein are observed, demonstrating the simultaneous and selective detection of these flavonoids possible. The AgNP/ZnONR@CFP sensor demonstrates a remarkable wide linear relationship with low detection limits for luteolin, daidzein, and baicalein detection in a mixed solution. When the sensor is employed to analyze luteolin, daidzein, or baicalein in real extracts from Japanese Honeysuckle, Soybean, and Chrysanthemum morifolium, satisfactory recovery rates (ranging from 96.3 % to 102.5 %) and low relative standard deviation (RSD) values (less than 5.0 %) are obtained. In addition, an assembled sensor device (two-electrode) based on this trimmable AgNP/ZnONR@CFP electrode exhibits remarkable quick response and excellent sensitivity for luteolin, daidzein, or baicalein detection, facilitating real-time and portable detection, highlighting its great potential in batch production of the sensor devices. [Display omitted] • A binder-free electrode is prepared for simultaneous luteolin, daidzein and baicalein detection. • The sensor exhibits high activity with wide linear range and low detection limit. • A two-electrode sensor device is assembled using the AgNP/ZnONR@CFP electrode. • The novel sensor device allows real-time, portable detection and paves the way for mass production. [ABSTRACT FROM AUTHOR]

• AgNPs were synthesized using Verbascum insulare Boiss. and Heldr. extract. • Extract content was determined by LC-MS/MS system. • NPs were characterized with FTIR, TGA, XRD, TEM, XPS, SEM-EDX, EDS analysis, and elemental mapping. • NPs have anticancer, antimicrobial activity and antioxidant potential. • NPs degraded methylene blue dye by 78 % in 180 min under UV–vis light. In recent years, due to the environmental friendliness of nanoparticle production, biosynthesis methods using plant extracts and possible physical, chemical, thermal and biological properties of the synthesized nanoparticles are frequently the subject of research. In the present study, hydrothermally assisted synthesis of Ag nanoparticles using twig-leaf extract of Verbascum insulare Boiss. and Heldr. , (VIE-AgNPs) a plant endemic to Turkey, was successfully carried out for the first time in this study. The presence of 24 of the 53 phytochemicals investigated in the content of the extract of Verbascum insulare Boiss. and Heldr. (VIE) determined by the LC-MS/MS system was detected. In addition, the amount of phenolic substance involved in reduction was found to be 60.42 ± 9.11 µg Gallic acid equivalent/mg-extract. The synthesized AgNPs were characterized by UV–visible spectra (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In particular, the surface plasmon band observed at 422 nm, the characteristic peaks observed in XRD, and the bond energy values seen in XPS strongly confirmed the formation of AgNPs. XRD and TEM data showed that AgNPs had an average size range of 25–30 nm. FTIR data indicated the presence of some herbal agents on the surface of AgNPs. The properties of the VIE-AgNPs were compared in vitro with chemically produced AgNPs (C-AgNPs). The OSI level of C-AgNPs was 87.78 ± 1.75 AU, while that of VIE- AgNPs was 110.42 ± 7.54 AU. It was observed that the nanoparticle and VIE used in the study had antimicrobial activity. It was determined that its antibacterial activity was stronger than its antifungal activity. When the analyzed inflammatory parameter levels (TNF-α, IL1β, TGF-β, and DEF-β2) were examined, the effect of VIE on inflammation in A549 cells could not be detected. However, it was determined that VIE-AgNPs, one of the nanoparticles used in the study, increased anti-inflammatory levels more than C-AgNPs. When the received data are evaluated together, it can be said that biosynthesized AgNPs suppress proliferation and stimulate apoptosis in cancer cells by increasing oxidative stress and inflammation levels compared to chemical AgNPs, thus showing an anticarcinogenic effect. It was found that VIE-AgNPs could effectively degrade the water pollutant methylene blue (MB) dye. VIE-AgNP mediated 78 % photocatalytic degradation of MB in 180 min. All superior biological properties are thought to be due to the low particle size and the interaction of active components with AgNPs during the biosynthesis process. Because it has been observed that VIE-AgNPs, which have a smaller particle size, have higher biological (cytotoxic, anticarcinogenic, inflammatory, etc.) activities than C-AgNPs. It can be said that AgNPs produced by biosynthesis may have potential use in the production of environmentally friendly, antibacterial/anticarcinogenic materials. [ABSTRACT FROM AUTHOR]

In this study, we report the fabrication of silver (Ag) nanoparticle-decorated vertically oriented β-Ga2O3 nanowires (NW) on Si substrate by the GLAD method. The samples were annealed at 900 °C after fabrication. When the sample is annealed, the average crystallite size increases while the lattice strain and dislocation density decrease. The formation of well-aligned vertically oriented nanowires is confirmed by FE-SEM images. The EDX and TEM analyses illustrates the presence of Ag nanoparticles on the β-Ga2O3 NW. The photoluminescence spectra demonstrate decreased luminescence intensity due to defect elimination during annealing. The UV–Vis absorption spectra of both samples reveal that the presence of Ag nanoparticles causes a substantial absorption hump in the visible range, extending the light absorption capabilities of β-Ga2O3. The fabrication of Ag nanoparticle-decorated β-Ga2O3 NW on Si substrate and annealing could be valuable in developing broadband light detection for various optoelectronic applications. [ABSTRACT FROM AUTHOR]

The die-bonding layer between chips and substrate determinates the heat conduction efficiency of high-power LED. Sn-based solder, AuSn20 eutectic, and nano-Ag paste were widely applied to LED interconnection. In this paper, the optical–thermal performances and high-temperature reliability of LED with these bonding materials have systematically compared and studied. The thermal conductivity, electrical resistivity, and mechanical property of these bonding materials were characterized. The LED module packaged with nano-Ag has a minimum working temperature of 21.5 °C. The total thermal resistance of LED packaged with nano-Ag, Au80Sn20, and SAC305 is 4.82, 7.84, and 8.75 K/W, respectively, which is 4.72, 6.14, and 7.84 K/W higher after aging for 500 h. Meanwhile, the junction temperature change of these LEDs increases from 2.33, 3.76, and 4.25 °C to 4.34, 4.81, and 6.41 °C after aging, respectively. The thermal resistance of the nano-Ag, Au80Sn20 and SAC305 layer after aging is 1.5%, 65.7%, and 151.5% higher than before aging, respectively. After aging, the LED bonded with nano-Ag has the better optical performances in spectral intensity and light output power, which indicates its excellent heat dissipation can improve the light efficiency. These results demonstrate the nano-Ag bonding material could enhance the optical-thermal performances and high-temperature reliability of high-power LED. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction (ECR) is one of the most effective methods to obtain carbonaceous chemicals and reduce greenhouse gases passingly under the ambient condition. However, efficient electrocatalysts featured with high selectivity and stability are still lacking. A novel molecule-mediated Ag electrocatalyst with capped thiols is rationally designed for high-performance ECR. The thiol-capped and carbon-supported Ag nanostructures (Ag-TC) are formed by in situ electrochemical reduction from three-dimentional (3D) Ag-thiol metal-organic compound with cysteine as the anchor agent and carbon source. Ag-TC exhibits high selectivity and stability for CO2 conversion to CO (86.7%), which is more catalytically active than that of common Ag nanoparticles. The function of thiols for ECR is proved by replacing cysteine with alanine without thiol group. Meanwhile, alternatively replacing and removing the surface molecules on the Ag foil further demonstrate the effect of thiols. This work enlightens the promise of in situ construction method for molecule capped metal electrocatalyst towards selective and stable ECR. [ABSTRACT FROM AUTHOR]

The variation behaviors of the morphology, transmission, and sheet resistance of the surface Ag/AgO nano-network (NNW) structures fabricated under different illumination conditions and with different Ag deposition thicknesses and thermal annealing temperatures in forming initial Ag nanoparticles (NPs) are studied. Generally, an NNW structure with a smaller mesh size or a denser branch distribution has a lower transmission and a lower sheet resistance level. Under the fabrication condition of a broader illumination spectrum, a lower thermal annealing temperature, or a thicker Ag deposition, we can obtain an NNW structure of a smaller mesh size. The mesh size of an NNW structure is basically controlled by the seed density of Brownian tree (BT) at the beginning of light illumination. A BT seed can be formed through a stronger local localized surface plasmon resonance for accelerating Ag oxidation in a certain region. Once an Ag/AgO BT seed is formed, the surrounding Ag NPs are reorganized to form the branches of a BT. Multiple BTs are connected to form a large-area NNW structure, which can serve as a transparent conductor. Under the fabrication conditions of a broader illumination spectrum, 3 nm Ag deposition, and 100 °C thermal annealing, we can implement an NNW structure to achieve ∼1.15 ÎĽ m in mesh size, ∼90 Ω sqâˆ'1 in sheet resistance, and 93%â€"77% in transmittance within the wavelength range between 370 and 700 nm. [ABSTRACT FROM AUTHOR]

The opportunistic pathogen, Pseudomonas aeruginosa, uses different mechanisms as well as biofilm production to acquire antibiotic resistance. The polysaccharide synthesis locus (psl) genes play an important role in P. aeruginosa biofilm formation. Therefore, targeting the expression of psl genes can be a suitable strategy to prevent the formation of biofilms by antibiotic-resistant strains. Today, advances in nanotechnology provide a novel potential strategy to combat antibiotic-resistant bacteria. In this study, the silver nanoparticles (Ag NPs) synthesized using a chemical co-precipitation method and, after conjugation with thiosemicarbazide, their effect on the biofilm-forming ability are studied in P. aeruginosa isolates. Chemical properties of synthesized nanoparticles were determined by scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. The results confirmed the spherical/cubic morphology, solution stability, and good dispersion of Ag@Glu–TSC NPs with an average size of 40–60 nm. In addition, minimum inhibitory concentration values of functionalized Ag NPs were at least twofold lower than the Ag NPs (alone). The quantitative PCR data analysis showed a decrease in the expression of the pslA gene in the presence of Ag@Glu–TSC NPs, up to 60%, which was associated with a reduction of biofilm formation compared to control. In conclusion, the Ag@Glu–TSC NPs can be considered a new inhibitor of biofilm production in antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]

This letter reports the synthesis of silver (Ag) nanoparticles (NPs) decorated on WO3 nanowires (NWs) using the glancing angle deposition (GLAD) technique for photodetector applications. Ag/WO3 NWs device reveals a significantly low dark current of $8.63\times10$ −11 A. The device also obtained a maximum photoresponsivity of 70.1 A/W and detectivity of $1.61\,\,\times10$ 14 Jones at 360 nm with an internal gain of 241. Moreover, the Ag decorated WO3 NWs shows a rise time of 0.84 s and a fall time of 0.78 s at an applied bias of 3V. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) spectroscopy has attracted increasing attention due to its high spectral reproducibility and unique selectivity to target molecules. Here, a facile approach is proposed to prepare Ag nanoparticles modified ZnO nanorod arrays (Ag/ZnO NR arrays). Ag nanoparticles were densely decorated on the surface of ZnO nanorods through silver mirror reaction and subsequent seed-assisted electrodeposition. The prepared Ag/ZnO NR arrays can be used as a sensitive, uniform, and repeatable SERS substrate for the rapid detection of organic dye molecules and biomolecules with concentrations higher than the corresponding limits of detection (LODs). The LODs for rhodamine 6G (R6G), 4-aminothiophenol (PATP) and adenine are calculated to be 1.0 × 10−13 M, 1.6 × 10−12 M and 3 × 10−11 M, respectively. The enhancement factor (EF) of the SERS substrate is estimated to be as high as ~2.7 × 108 when detecting 10−10 M R6G. Particularly, the as-synthesized substrate exhibits high selectivity to multiple components. In addition, the fabricated Ag/ZnO NR arrays can be recycled due to their superior self-cleaning ability and can realize photocatalytic degradation of R6G in water within 1 h driven by UV light, showing that the three-dimensional recyclable SERS substrates have wide applications in environmental pollution monitoring and biomedical analysis.