Ag Phase Research Articles

Single layered Ag/NiO plasmonic nanocoatings: A new green synthesis method for selective solar absorber

This study presents the synthesis of environmentally benign, single-layered spectrally selective Ag/NiO nanocoating absorbers using a green synthesis method. Various characterization techniques, including Rutherford backscattering spectroscopy (RBS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), were used to examine the effects of plasmonic Ag concentration on the structural, chemical composition, and surface morphology of the nanocomposites. The optical properties of the deposited nanocoatings were investigated using a UV–Vis-NIR spectrophotometer in the solar spectrum region (300–2500 nm) and an FT-IR spectrophotometer in the infrared wavelength region (3000–20,000 nm). XRD results confirmed the coexistence of a face-centered cubic phase of Ag and NiO in the Ag/NiO nanocermet thin films. SEM and TEM topography revealed uniformly distributed nanosphere NiO thin films and cubic Ag metal with better dispersibility and crystallization. The RBS spectrum of the samples showed a homogeneous distribution of Ni, Ag, and O atoms throughout the coatings. Ag/NiO nanocoatings deposited with 8 wt% Ag content exhibited excellent solar absorptance (α) = 0.95 and thermal emittance of (ɛ) of 0.08. This enhancement is primarily attributed to the localized surface plasmon resonance (LSPR) effect associated with the embedded Ag nanoparticles, which facilitates more effective utilization of light.

The Elevated Temperature Tribological Performance of Tough and Superhard TaMoN-Ag films with Solute and Nanocomposite Structures

Abstract Films have been prepared with not only high hardness to guarantee excellent wear resistance but also high toughness to prevent brittle fracture at low to middle-high temperatures. On the basis of ternary transition metal nitrides with significantly improved hardness and toughness, TaMoN-Ag films with solute and nanocomposite structure were prepared by DC magnetron sputtering technology. Friction wear tests were performed between room temperature (RT) and 700 °C. When doping with trace amounts of Ag atoms (∼1.12 at.%, 4 W), TaMoN-Ag films maintain solid solution structure. TaMoN-Ag films with the Ag target power is 4 W show the highest hardness (H∼62.1 GPa), which is 58% higher than TaMoN film and 44% better than that of TaMoN films. Meanwhile, a lower wear rate (KIC∼5.87×10-7 mm3/N·m) is obtained. The tribological properties of TaMoN-Ag films at room temperatures are related to the H3/E2 and lubricious Ag phase, while the tribological properties at high temperatures are mainly due to the formation of lubricating binary metal oxides (AgxTMyOz (Magnéli phases)). The composite films generally have good resistance to plastic deformation.

Eco-Friendly Photocatalytic Treatment of Dyes with Ag Nanoparticles Obtained through Sustainable Process Involving Spirulina platensis

The development of efficient photocatalysts is crucial in addressing water pollution concerns, specifically in the removal of organic dyes from wastewater. In this context, the use of silver nanoparticles (Ag NPs) might represent a method to achieve high dye degradation efficiencies. On the other hand, the classical Ag NP production process involves several reactants and operating conditions, which make it poorly sustainable. In the present work, Ag NPs were synthesized according to a new sustainable process involving the use of natural extracts of Spirulina platensis and milder operating conditions. The material was also calcined to determine the influence of organic content on the properties of Ag NPs. The X-ray diffraction (XRD) analysis displayed the AgCl and Ag phases with a crystalline size of 11.79 nm before calcination. After calcination, only the Ag phase was present with an increased crystalline size of 24.60 nm. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the capping role of the metabolites from the extract. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) revealed the spherical or quasi-spherical morphologies with agglomeration due to the calcination. Energy-dispersive X-ray spectroscopy (EDX) and Thermogravimetric (TGA) analyses further confirmed the involvement of metabolites in the synthesis of Ag NPs. The optical changes in the products were observed in a UV-Vis analysis. The Ag NPs were tested for their photocatalytic activity against the laboratory dye brilliant blue r in visible light in various conditions. The highest degradation efficiency of 81.9%, with a kapp value of 0.00595 min−1, was observed in alkaline medium after 90 min of light irradiation.

Preparation of pure phase silver nanoparticles: Morphological, optical, binding interactions with bovine serum albumin and antioxidant potential studies

Pure silver nanoparticles (AgNPs) were synthesized using Senecio madagascariensis plant extract and oleic acid as capping agents. The powder X-ray diffraction patterns of the silver nanoparticles were indexed to the face-centred cubic phase of Ag. TEM images of the nanoparticles revealed polydisperse spherical nanoparticles with particle size of 9 to 22 nm range. The GC-MS revealed terpenes as some phytochemicals extracted, which the FTIR bands corroborated. The results confirmed that increase in oleic acid concentration increased the size of the silver nanoparticles. The nanoparticles' optical band gaps, Eg, were 2.26 – 2.56 eV, which decreased with particle size. The AgNPs exhibited potential antioxidant activity, as demonstrated by the DPPH scavenging assay. The DPPH scavenging activity was highest, with AgNP1 at 80 % and an IC50 of 1.668 μg/mL. Fluorescence and ultraviolet (UV) titrations were used to study the interaction of the silver nanoparticles (AgNP1) with bovine serum albumin (BSA). The Kapp value of the AgNP1 was calculated to be 3.14 × 104 ± 0.02 Lmol−1, KSV calculated as 7.38 × 104 ± 0.12 M−1. In the study, AgNPs bind to BSA potentially through a static quenching mechanism with one binding site that leads to developing a ground state complex. It is proposed that AgNPs bond to BSA's surface spontaneously based on its thermodynamic characteristics and binding constants.

Refinement of eutectic structure and precipitates of Cu–20Ag alloy due to Y microalloying

Copper-silver alloy rod with high mechanical properties and stable conductivity are the key materials for the preparation of microfilaments used in endoscopy and other medical fields. In this paper, the microstructure of Cu–20Ag rod was regulated by adding trace rare earth Y in order to improve the comprehensive performance of copper-silver alloy further. and studies the distribution and existence of rare earth Y as well as the influence on the performance of copper-silver alloy rod billet. The results of research show that: rare earth Y mainly exists in the branching nodes of the eutectic organization, so that the alloy in the solidification of constitutional supercooling increases, thus refining the eutectic structure, and make it uniformly distributed. After addition of 0.01 wt%Y, Cu4Y was precipitated in the eutectic structure of the rod. After adding 0.03 wt%Y, the precipitates types increased to trace intermetallic compound AgY and nanoparticles Cu4Y. The increase of the interface between eutectic structure and Cu matrix decreases the electron scattering probability. This is the main factor to lead to the decrease of electrical conductivity. The precipitation hardening of precipitated phase and the increase of interface between eutectic structure and Cu matrix are the main factors for the increase of tensile strength of bar billet. The main factor of the decrease in the conductivity of rod billet is the increase of Ag phase dissolved in eutectic structure and the interface between eutectic structure and Cu matrix.

The AUREX cell: a versatile operando electrochemical cell for studying catalytic materials using X-ray diffraction, total scattering and X-ray absorption spectroscopy under working conditions.

Understanding the structure-property relationship in electrocatalysts under working conditions is crucial for the rational design of novel and improved catalytic materials. This paper presents the Aarhus University reactor for electrochemical studies using X-rays (AUREX) operando electrocatalytic flow cell, designed as an easy-to-use versatile setup with a minimal background contribution and a uniform flow field to limit concentration polarization and handle gas formation. The cell has been employed to measure operando total scattering, diffraction and absorption spectroscopy as well as simultaneous combinations thereof on a commercial silver electrocatalyst for proof of concept. This combination of operando techniques allows for monitoring of the short-, medium- and long-range structure under working conditions, including an applied potential, liquid electrolyte and local reaction environment. The structural transformations of the Ag electrocatalyst are monitored with non-negative matrix factorization, linear combination analysis, the Pearson correlation coefficient matrix, and refinements in both real and reciprocal space. Upon application of an oxidative potential in an Ar-saturated aqueous 0.1 M KHCO3/K2CO3 electrolyte, the face-centered cubic (f.c.c.) Ag gradually transforms first to a trigonal Ag2CO3 phase, followed by the formation of a monoclinic Ag2CO3 phase. A reducing potential immediately reverts the structure to the Ag (f.c.c.) phase. Following the electrochemical-reaction-induced phase transitions is of fundamental interest and necessary for understanding and improving the stability of electrocatalysts, and the operando cell proves a versatile setup for probing this. In addition, it is demonstrated that, when studying electrochemical reactions, a high energy or short exposure time is needed to circumvent beam-induced effects.

Optimization of Brilliant Blue R photocatalytic degradation by silver nanoparticles synthesized using Chlorella vulgaris

Synthesis of silver nanoparticles (Ag NPs) using microalgae is gaining recognition for its environmentally friendly and cost-effective nature while maintaining high activity of NPs. In the present study, Ag NPs were synthesized using a methanolic extract of Chlorella vulgaris and subjected to calcination. The X-ray diffraction (XRD) analysis showed a crystalline nature of the products with Ag2O and Ag phases with an average crystalline size of 16.07 nm before calcination and an Ag phase with 24.61 nm crystalline size after calcination. Fourier transform infrared spectroscopy (FTIR) revealed the capping functional groups on Ag NPs, while scanning electron microscopy (SEM) displayed their irregular morphology and agglomeration after calcination. The organic coating was examined by energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric (TGA) analyses, confirming the involvement of the metabolites. The UV–Vis analysis showed a difference in optical properties due to calcination. Synthesized Ag NPs were applied for the photodegradation of hazardous dye Brilliant Blue R in visible light. Different values of light intensity, catalyst dose, initial dye concentration, and pH were tested to identify the optimal set of operating conditions. The highest degradation efficiency of 90.6% with an apparent rate constant of 0.04402 min−1 was achieved after 90 min of irradiation in the highest tested catalyst dosage.

Preparation and arc erosion mechanism of Ni skeleton reinforced Ag-based contact materials with CuO-coated SnO2

The Ag-SnO2 contact material is widely regarded as the most promising environmental friendly electrical contact material. However, during the make and break operations, SnO2 particles rising to the surface can cause increased contact resistance and temperature rise, which affects the service life of the contact material. In this study, a three-dimensional (3D) Ni skeleton reinforced Ag-based contact material with CuO-coated SnO2 are successfully fabricated via powder metallurgy technology. The basic physical properties of the novel contact material were tested and the microstructures and arc erosion morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The research demonstrated that the hardness and electrical conductivity of the novel contact material are 128.9 HV and 46 %IACS, respectively. It can be observed that the SnO2-rich phase is uniformly distributed in the Ag matrix without significant upward after arc erosion, which indicates that the SnO2@CuO core-shell structure effectively enhances the wettability between Ag and SnO2. Meanwhile, the study revealed that the Ni phase uniformly distributed at the interface of the Ag phase during the arc erosion process, indicating that the 3D Ni skeleton structure effectively impedes the expansion of the Ag molten pool and improves the anti-arc erosion performance.

Metastable phases of Ag–Si: amorphous Si and Ag-nodule mediated bonding

Metastable phases such as supersaturated solid solutions, supercooling, and amorphous phases are well-known in metallurgy. They are often composed in non-equilibrium states and can be transformed into a stable phase by overcoming an energy barrier with driving forces. Particularly, it has been widely used for material strengthening and heterogeneous nucleation of precipitates in solids is mainly induced by heat treatments for supersaturated solid solutions. However, little is known about the metastable phases of the Ag–Si alloy, although it is a well-known simple binary eutectic alloy. Here, we show that the metastable phases composed of amorphous Si and supersaturated Ag solid solution are induced by the eutectic reaction under rapid cooling of Ag–Si. Furthermore, the solute Si in the Ag matrix reacts with oxygen to precipitate Ag by-products, which grow as nodules. The Ag nodules have high crystallinity and robust interfacial structures, and the nodule growth leads to the formation of cross-links between the Ag–Si particles. We also demonstrate the Ag nodule-mediated bonding where the rapidly cooled Ag–Si ribbon is directly used as a bonding medium, indicating the possibility of using it as a high-temperature bonding material with low-temperature processes.

Electro-Thermo-Magnetic Effect-Induced Large Thermoelectric Performance of Calcium Cobaltite Nanocomposites.

As attractive thermoelectric oxides, Ca3Co4O9-based materials have been intensively studied for their applications in recent years. However, their thermoelectric performance is enormously limited due to the contradiction of electrical resistivity and thermal conductivity. Herein, BaFe12O19 nanospheres were introduced into the Ca3Co4O9 matrix. The metallic Ag, ferrites, and matrix phase survived together, and a high density of nanoscale BaFe12O19 precipitation was observed. The reduction of work function could lead to band bending and form an interface potential due to the electro-thermo-magnetic effect contributing to the hole migration. As a result, a huge ZT value of 0.51 for the 8 wt % BaFe12O19/Ca3Co4O9 nanocomposites was obtained at 1073 K, accompanied by a low electrical resistivity of 6.7 mΩ·cm and a high Seebeck coefficient of 217.5 μV/K. In addition, a significant reduction of thermal conductivity (1.11 W/(m·K)) occurred, which was due to the nanoscale ferromagnetic phase effectively scattering the mid- and short-wavelength heat-carrying phonons. The synergistic enhancement of thermoelectric performance confirmed that the electro-thermo-magnetic effect is an effective way to solve the challenging problem of performance deterioration in oxide thermoelectric materials.

Green synthesis of magnetic silver nanocomposite: the photocatalytic performance of nanocomposite to decolorize organic dyes

ABSTRACT The magnetite-silver nanocomposites (Fe3O4-Ag NCs) were synthesized via a facile and green process by Citrus sinensis peel extract. The deposition of silver nanoparticles (NPs) was confirmed by observing an absorption peak at the maximum wavelength at 422 nm in the suspension solution of samples, which is related to silver surface plasmon resonance (SPR). The characteristic diffraction patterns of Fe3O4 and Ag phases were characterized utilizing the XRD patterns and the average size of the crystals was 21 nm. The photocatalytic behavior of Fe3O4-Ag NCs was studied for the destruction of three organic dyes methyl green (MG), methyl orange (MO), and methylene blue (MB) below UV radiation. The effect of the amount of photocatalyst and volume of hydrogen peroxide as an oxidant in the process of dye degradation was also investigated. The complete degradation time of dyes MB, MG, and MO under UV irradiation in the presence of 0.002 g Fe3O4-Ag NCs were 57, 33, and 49 min, respectively. The time of degradation reactions showed the high photocatalytic performance of Fe3O4-Ag NCs. These results proved that the synergistic effect of magnetite in the role of supporting the silver NPs was a significant contribution to the excellent decolorization behavior of Fe3O4-Ag NCs.

Synthesis of Silver Nitrate by Evaporation Chemical Reduction Process as Potential Materials for Silver Nanowires Application

In this study, we conducted the extraction of silver nitrate (AgNO3) using the chemical reduction evaporation method, involving silver metal (Ag) with a molarity of 7.716 M and nitric acid (HNO3). The heating process via evaporation was carried out at 85oC for 2 hours. Subsequently, the synthesis of silver nanowires (AgNWs) was performed using a 0.3 M of AgNO3 solution in ethylene glycol (EG), polyvinyl pyrrolidone (PVP), and Iron (III) Chloride hexahydrate (FeCl36H2O). XRD analysis of the AgNO3 sample revealed an orthorhombic crystal structure with a single AgNO3 phase peak. In AgNWs, three crystalline phases were observed, with the Ag phase being the most dominant. The average crystal size of AgNO3 and AgNWs was 109.42 nm and 22.06 nm, respectively. The average crystal size of the AgNO3 sample may be influenced by the aggregation between crystal nuclei during the heating process. XRF analysis indicated a 98.84% Ag concentration in AgNO3. SEM-EDS analysis showed that the AgNO3 sample had a non-aggregated morphological structure, with particle size measuring 49.46 μm and an overall AgNO3 purity of 92.68%. The SEM image of the AgNWs sample displayed a very homogeneous diameter of ∼200 nm with a length of around 10-20 μm. Meanwhile, AgNWs exhibited a morphology resembling rod-shaped wires with a purity of 68% for Ag.

Electrical switching properties of Ag2S/Cu3P under light and heat excitation

In this paper, we prepared and investigated the electrical switching behaviors of Cu3P/Ag2S heterojunction in the absence/presence of light/heat excitation. The structure exhibited bipolar memristor characteristics. The resistive switching mechanism is due to the formation of Ag conductive filaments and phase transition in Cu3P. We found that the resistance ratio (ROFF/RON) increased by a factor of 1.4/1.8 after light/heat excitation. The underlying mechanism was due to the photoelectric effect/Seebeck effect. Our results are helpful for the understanding of the resistive switching performance of Cu3P/Ag2S junctions, providing valuable insights into the factors influencing resistive switching performance and a clue for the enhancement of the memristor performance.

Structural characterization and mechanical properties of bicontinuous dual-metal composites prepared by liquid metal dealloying

Most bicontinuous dual-metal composites (BDMCs) generated by liquid metal dealloying (LMD) exhibit lamellar microstructures at the grain boundaries of initial precursor alloys, resulting in little to no ductility. Herein, grain-boundary-defect-free bicontinuous Ni/Ag composites consisting of network-like dealloying structures (Ni phase) and solidified matrices of liquid metal corrosive media (Ag phase) are prepared. Then, a detailed study of their intrinsic structures and mechanical properties under uniaxial tension is conducted. This composite is found to be completely dense without visible holes or cracks. Both the Ni phase and Ag phase have independent open porous structures and are well bonded with clear interfaces, forming a dual-interlocking structure with phase-to-phase and grain-to-grain interlocking. This structure does not significantly affect the elastic modulus or tensile yield strength, but under specific conditions, it can enhance the tensile ductility because of the coordinated deformation between the two phases, thereby reducing the likelihood of stress concentration and delays necking. Moreover, these bicontinuous Ni/Ag composites display superior strain hardening rates in comparison to pure Ag. The high strength and ductility of this structure warrant the exploration of its practical application in many areas, if more defect-free systems are synthesized by optimizing the LMD process in the future.

Enhanced photocatalytic activity in AgCu-decorated ZnO nanoparticles under UV and sunlight

This study investigates the structural, morphological, and photocatalytic properties of monometallic (Ag and Cu) and bimetallic (AgCu) nanoparticles (NPs) incorporated into ZnO NPs and their photocatalytic performance. X-ray diffraction and Rietveld refinement were employed to analyze the structural characteristics, revealing the formation of a hexagonal wurtzite structure of ZnO and cubic phases of Ag and Cu within the metal-decorated NPs. Scanning electron microscopy provided visual evidence of the spherical morphology, with an average particle size of 50 nm. Energy-dispersive X-ray spectroscopy confirmed the successful deposition of Ag, Cu, and AgCu NPs onto the ZnO surface. The photocatalytic efficiency of the NPs was evaluated by the degradation of methylene blue dye under UV light at a wavelength of 254 nm under sunlight irradiation. Under UV light, the bimetallic AgCu/ZnO system exhibited exceptional performance, achieving a degradation rate of about 95% with 10% AgCu/ZnO. Conversely, under sunlight illumination, the monometallic Cu/ZnO and Ag/ZnO NPs exhibited outstanding photocatalytic properties, with degradation rates of about 99 and 98%, respectively. These findings underscore the influence of the light source on photocatalytic performance as well as the significance of the plasmonic effects and charge-transfer mechanisms.

Effects of Ag/Sc microadditions on the precipitation of over-aged Al–Zn–Mg–Cu alloys

Microalloying addition plays a significant role in controlling the characteristics of precipitates in Al alloys. This study investigates the effects of Ag and Sc microalloying addition on the thermal stability of Al–Zn–Mg–Cu alloys, via differential scanning calorimetry, transmission electron microscopy, and atom-probe tomography. The results demonstrate that Ag and Sc additions increase the number density of η-MgZn2 type nano-precipitates (formed during heat treatment) by forming direct (Mg–Ag phase, prototype of precipitate) or indirect precursors (Al2Sc phase, constituent of precipitate) for the precipitate. In addition, the Ag and Sc elements can effectively prevent the coarsening of η precipitates and facilitate the high-density distribution of fine η precipitates, during the over-aging period, improving the thermal stability of the Al–Zn–Mg–Cu alloys. The thermal stability is particularly improved by Ag addition because Ag atoms directly prevent the coarsening of η precipitates by hindering Zn diffusion into the precipitate. On the contrary, Sc addition indirectly prevents the coarsening of η precipitates by depleting the solute species from the Al matrix, enabling abundant precipitates limited growth. Thus Ag addition improves precipitation strengthening by preventing the coarsening of precipitates during over-aging.

Separation and purification of Ag and Se via vacuum thermal decomposition-volatilization of Ag2Se

In this study, theoretical and experimental investigations of the green separation and purification of Ag and Se from Ag2Se are conducted under vacuum. The vacuum separation theory calculation results indicate that the vapor pressure of Se is significantly higher than those of Ag and Ag2Se. Furthermore, the separation coefficient of the Se-Ag binary system is in the range of 104–105, and the Se content in the vapor phase exceeds 99.99 wt%. In contrast, the theoretical calculation results of vacuum thermal decomposition show that Ag2Se decomposes to Se2 (g) and Ag (l) at 1326.74 and 1488.21 K when the pressures are 1 and 10 Pa, respectively. The vacuum separation and purification experiments demonstrate that the purity of Se in the volatiles reaches 97.22 wt% at 1523 K, 50 Pa, and 480 min, and the main phase is the pure Se phase. Moreover, the purity of Ag in the residue reaches 91.88 wt%, and the main phase is the pure Ag phase. The vacuum thermal decomposition-volatilization proposed in this study can achieve environmentally friendly, short separation and purification of Ag and Se in Ag2Se.

Plastic quasicrystal-containing alloys prepared by annealing pseudo-high entropy Zr70–75(Al, Ni, Cu, Ag)25–30 glassy alloys

A glassy (G) phase was formed for Zr-rich Zr70–75(Al, Ni, Cu, Ag)25–30 (atomic percent, at.%) melt-spun alloy ribbons. These glassy alloys exhibit the glass transition, followed by a supercooled liquid region and then three-stage crystallization. The glass transition temperature and the onset temperature for the first-stage crystallization (Tx1) decrease from 630 to 668 K, respectively for the 70Zr alloy to 619 and 652 K, respectively for the 75Zr alloy. The first-stage exothermic peak is due to the precipitation of an icosahedral quasicrystal (IQ) phase. The IQ particle size decreases from 10 nm to 6 nm with increasing Zr content from 70at.% to 74at.%. The [G + IQ] phases change to Zr2Ni + Zr2(Cu, Ag) phases after the second exothermic peak and then Zr2Ni + Zr2(Cu, Ag) + Zr5Al3 phases after the third stage. It is noticed that the as-spun glassy alloy ribbons as well as the annealed [G + IQ] phase ribbons exhibit good bending plasticity. Furthermore, the 70Zr thicker ribbons also exhibit high tensile fracture strength of 1090–1187 MPa and plastic elongation of 0.17 %–0.42 %. The fracture mode is similar to that of ordinary bulk metallic glasses. The Vickers hardness (Hv) is 480 for 70Zr alloy and decreases to 436 for 75Zr alloy. The precipitation of IQ phase causes a significant increase in Hv to about 554. The formations of glassy alloys with high Zr contents of 70at.%–75at.% by melt spinning as well as the [G + IQ] phase alloys with good bending plasticity by annealing hold promise for the creation of a new type of engineering material, transcending mere academic novelty.

Fabrication and Characterization of Silver Nanoparticle-Doped Chitosan/Carboxymethyl Cellulose Nanocomposites for Optoelectronic and Biological Applications.

The synthesis of nanoparticles using environmentally friendly methods for applications in fields such as food packaging and biomedicine has been gaining increasing attention. Organic-inorganic nanostructures offer opportunities to create innovative materials suitable for use in optoelectronics and biological applications. In this study, we focused on producing nanocomposite films by blending carboxymethyl cellulose (CMC) and chitosan (CS) polymers in equal proportions (50/50 wt %) and adding silver nanoparticles (Ag NPs) through a solution casting process. Our objective was to examine how the introduction of Ag NPs influenced the structural, optical, mechanical, electrical, and antibacterial properties of the virgin CMC/CS composites. XRD patterns of the prepared samples indicated the presence of crystalline Ag phases within the CMC/CS blend. FT-IR spectroscopy showed the primary vibrational peaks associated with CMC and CS, which exhibited reduced intensity after the addition of Ag NPs. The UV absorption of the nanocomposites exhibited a gradual increase and a shift toward longer wavelengths. The electrical properties are enhanced with higher concentrations of Ag NPs. An increase in the content of Ag NPs resulted in a corresponding enhancement of antibacterial activity against both Staphylococcus aureus and Escherichia coli. The CMC/CS-Ag-doped films demonstrated significant enhancements in Young's modulus (Y), tensile stress (σt), and elongation at break (εB). These findings suggest that these nanocomposite films hold promise for potential applications in optoelectronics and biological fields.

Bactericidal efficiency of silver nanocomposites obtained using Brewer’s spent grains

Silver nanocomposites were prepared using extracts resulting from different extraction methods of brewer’s spent grains (BSG) herein called BW3. Extracts were prepared using solvent (acetone and methanol aqueous solutions, and water) extraction methods, ultrasonic and microwave-assisted methods, and alkaline-acid hydrolysis.Extraction conditions influenced the composition of extract solutions differing in the amount of Na, K, P, Mg, Ca, Zn, and SO4−, Cl−, and NO3– anions, wherein predominantly varying contents of P and anions influenced the properties of the nanocomposites. Nanocomposites exhibited three major crystalline phases, namely, Ag3PO4 (9–74 wt%), Agmet (25–84 wt%), and AgCl (∼1–5 wt%) with different Ag crystallite sizes. Nanoparticles of different Ag phases were capped by organic structures consisting of chemical groups such as C–OH, C = O, C–OOH, –NH, and –PH. The thermal stability of the nanocomposites increased with increasing Agmet phase content.The minimum inhibitory concentration (MIC) of nanocomposites for Escherichia coli was as low as 4 μg mL−1. The antibacterial efficiency depended on the amount of (i) Ag+ ions from different Ag phases and their solubility, (ii) positively charged P and N hydrogen forms, (iii) negatively charged C groups and vacancies, and (iv) Ag phases crystallite size.