Percentage Of Ag Research Articles

Optical Properties and Performance of Pristine and Ag‐Doped ZnO as Working Electrode in Dye‐Sensitized Solar Cells

ABSTRACTDye‐sensitized solar cell (DSSC) is a potential low‐cost solar energy conversion device that is simple to fabricate with low cost than traditional silicon‐based solar cells. The development of DSSC is hampered by the limitations of using ZnO‐based photoanodes for a number of reasons (e.g., charge recombination, efficiency and expensive method). Photoanode material is one of the crucial components in DSSC, which plays a vital role in overall device performance, and the improvement of photoanode materials is needed. This work is focused to improve the overall performance of DSSCs with reducing problem by incorporating a dopant into ZnO semiconductor material as photoanode. Pristine and silver‐doped zinc oxide (Ag‐ZnO) photoanodes with various weight percentages of Ag (2, 3 and 4 wt%) were prepared by a facile, cost‐effective and quick green‐modified–solvothermal method with diethylamine (precipitating agent) and fig leaf extract (capping agent). The structural, crystalline nature, morphological and optical properties of prepared nanomaterials were analysed using X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM) and UV–Vis spectrophotometry. The results revealed that the crystallite size of pristine and Ag‐ZnO with 2, 3 and 4 wt% of Ag decreased from 85 to 21 nm by increasing the percentage of Ag. The surface roughness decreased with increasing the weight percentage of Ag, and there is no big change in their morphology. The energy band gaps (Eg) of pristine and Ag‐ZnO with 2%, 3% and 4% Ag determined by Tauc plot were 2.55, 3.05, 3.09 and 3.17 eV, respectively. Among the pristine and Ag‐doped ZnO fabricated devices, the photovoltaic measurements of 4% Ag‐ZnO exhibited superior performance reaching the highest efficiency of 2.25% with a short‐circuit current density (JSC) of ~5.8 mA/cm2, an open‐circuit voltage (VOC) of ~810 mV and a fill factor (FF) of ~0.54, which might be due to large optical band gap, better conductivity, reduced recombination rate and enhanced dye adsorption.

Isothermal aging effect on SAC interconnects of various Ag contents: Nonlinear simulations

Abstract The mechanical behavior of the tin (Sn)–silver (Ag)–copper (Cu) (SAC) lead-free solders is strongly influenced by the isothermal aging due to the evolution of the microstructure and mechanical properties. This study aims to examine the influence of pre-isothermal aging at 100°C on the mechanical behavior of different SACN05 alloys with different silver content including N = 1 , 2 , 3 N=1,\hspace{.25em}2,\hspace{.25em}3 and 4% by applying nonlinear finite element analysis. The mechanical properties, including elastic and inelastic properties, of the SAC systems with various Ag percentages are gathered from the literature and incorporated in thorough thermomechanical simulations. In addition to the unaged solders condition, two aging periods, 6 and 12 months, are studied. The computational results showed that the mechanical response of pre-aged SACN05 solders is significantly influenced by the aging duration and silver content. Specifically, interconnects with higher Ag percentage are shown to be more resistive to aging and expected to have lower thermally induced inelastic deformations, strains, and strain energies. Therefore, better thermal fatigue performance and improved failure resistance is potentially expected. However, the pre-isothermally aged SACN05 solders generally exhibit lower resistance to the accumulations of inelastic strains and strain energies. Thus, it is probable that pre-aged SACN05 solders will demonstrate deterioration in thermal fatigue performance compared to unaged interconnects. Nonetheless, the aged SAC solder systems could be an innovative solution for designing electronic devices regularly exposed to shock and impact loading as the aging process significantly reduces the brittleness of the SnAgCu alloys.

Biosynthesis of silver nanoparticles (AgNPs) from coconut leaf extract and their antifungal activity against Ganoderma boninense mycelia

Basal stem rot disease caused by Ganoderma is a major problem in palm cultivation in Indonesia, so an appropriate solution is needed to overcome this problem. One of the solutions that can be applied is through silver nanoparticles. Synthesis of silver nanoparticles can use coconut leaves as a source of flavonoids. Flavonoids are one of the phenolic compounds that are widely used in the process of synthesizing silver nanoparticles. Flavonoid compounds have a hydroxyl group (OH), which can be reduced by donating electrons to the Ag+ ion from AgNO3 to Ag0. This research aims to synthesize silver nanoparticles (AgNPs) using coconut leaf water extract and its assessment as an antifungal for Ganoderma boninense. Silver nanoparticles were synthesized by mixing coconut leaf extract in 1 mM of AgNO3 solution with a ratio of 1:9 (v/v). The concentrations of coconut leaf water extract were 1% and 3% with a heating temperature of 60°C. Silver nanoparticles were characterized using a UV-Vis spectrophotometer, PSA, FTIR, TEM, and SEM-EDS. The AgNPs had a maximum wavelength of 430 nm, with morphologies like a ball, triangle, and square, a mass percentage of Ag of 51.77%, smallest particle size of 63.29 nm, PdI value of 0.3361, and a zeta potential of -16.98 mV. The FTIR spectra show that the functional group that plays a role in the reduction process is the –OH group. The antifungal activity assay produced the highest percentage of colony growth inhibition (68.37%) at a concentration of 4.9 ppm in the 10-day incubation.

Synthesis of Ag/Cu decorated 3D self-assembled nanowire TiO2 photocatalyst for hydrogen production: a promising pathway towards sustainable energy generation.

Here, synthesis and characterization of TiO2 with different morphologies along with the cost-effective bimetallic decoration on optimized 3D self-assembled nanowire TiO2 (NWT) photocatalyst (Ag/Cu-NWT) with overwhelming hydrogen production rate is reported. All the photocatalysts were well characterized by different characterization techniques. Initially, the effect of morphology change obtained by changing the NaOH concentration has been studied for TiO2. Morphology obtained at 10M NaOH solution, i.e., NWT (678μmol/g), showed better hydrogen production than morphology obtained at 5M (410μmol/g), 15M (210μmol/g), and 20M (160μmol/g) NaOH solutions. Further, with the aim to achieve comparable or better activity low-cost photocatalyst as compared to Pt-TiO2 system, NWT was decorated with various Cu percentages and then with a minimal percentage of Ag on an optimized Cu-NWT photocatalyst. The observed trend for photocatalytic hydrogen production has been found to be P25 TiO2 < NWT < 1.0Cu-NWT < 0.5Pt-NWT ≤ 0.1Ag/1.0Cu-NWT. The marked increase by a factor of 103 in hydrogen production for the optimized bimetallic 0.1Ag/1.0Cu-NWT (10,184μmol/g) photocatalyst compared to P25 TiO2 (99μmol/g), nearly threefold increment in hydrogen production than an optimized 1.0 Cu-NWT (3907μmol/g) photocatalyst and comparable hydrogen production as compared to 0.5Pt-NWT (10,050μmol/g) may be attributed to the successful synthesis of a highly porous NWT morphology, which offers large surface area, increased light absorption combined with the synergistic effects of surface plasmon resonance (SPR), and the Schottky barrier for H+ reduction to H2 gas. The optimization of TiO2 morphology and an inexpensive bimetallic decoration strategy opens up promising opportunities for the development of cost-effective photocatalysts in the realm of energy and environment.

Impact of plasmonic silver on the perovskite Bi9Ti6FeO27: Removal of tetracycline and antimicrobial activity

The synthesis, characterization, photocatalytic, and antibacterial analysis of plasmonic Ag- loaded Bi9Ti6FeO27 at various concentrations of Ag are presented in this study. The synthesis of Ag/Bi9Ti6FeO27 is based on the impregnation of different weight percentages of Ag (20, 50, and 80) on Bi9Ti6FeO27. The XRD and HRTEM result shows that the perovskite Bi9Ti6FeO27 maintained orthorhombic crystallinity having space group Pnm (No.62). Upon addition of Ag, do not disturb the crystallinity of Bi9Ti6FeO27. XPS analysis displays the valence states and surface chemical composition of the as-prepared Ag/Bi9Ti6FeO27. All the composites exhibit good UV–visible absorbance in the range of 200–800 nm, and the band-gap energy gradually decreases from 3.30 eV to 2.73 eV with an increase in silver content. The photocatalytic degradation of 40 ppm tetracycline is examined at 120 min at neutral pH (7). Loading of Ag on Bi9Ti6FeO27 significantly promoted the photocatalytic degradation efficiency of tetracycline (84 %). Furthermore, the antibacterial activity of Ag/Bi9Ti6FeO27 was investigated against “Escherichia coli”, Klebsiella pneumoniae”, and “Acinetobacter baumannii” bacteria. Higher loading of Ag on Bi9Ti6FeO27 exhibited the most potent antibacterial activity by effectively inhibiting the growth of both bacterial strains through reactive oxidative species and the presence of silver nanoparticles. The composite has proved its stability through the five repeated cycles. This work provides an emerging strategy to finely design the nanocomposites and highlight their potential for environmental remediation and healthcare industries.

Bacteriogenic synthesis of morphologically diverse silver nanoparticles and their assessment for methyl orange dye removal and antimicrobial activity.

Nanotechnology and nanoparticles have gained massive attention in the scientific community in recent years due to their valuable properties. Among various AgNPs synthesis methods, microbial approaches offer distinct advantages in terms of cost-effectiveness, biocompatibility, and eco-friendliness. In the present research work, investigators have synthesized three different types of silver nanoparticles (AgNPs), namely AgNPs-K, AgNPs-M, and AgNPs-E, by using Klebsiella pneumoniae (MBC34), Micrococcus luteus (MBC23), and Enterobacter aerogenes (MBX6), respectively. The morphological, chemical, and elemental features of the synthesized AgNPs were analyzed by using UV-Vis spectroscopy (UV-Vis), Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy-dispersive spectroscopy (EDX). UV-Vis absorbance peaks were obtained at 475, 428, and 503 nm for AgNPs-K, AgNPs-M, and AgNPs-E, respectively. The XRD analysis confirmed the crystalline nature of the synthesized AgNPs, having peaks at 26.2°, 32.1°, and 47.2°. At the same time, the FTIR showed bands at 599, 963, 1,693, 2,299, 2,891, and 3,780 cm-1 for all the types of AgNPs indicating the presence of bacterial biomolecules with the developed AgNPs. The size and morphology of the AgNPs varied from 10 nm to several microns and exhibited spherical to porous sheets-like structures. The percentage of Ag varied from 37.8% (wt.%) to 61.6%, i.e., highest in AgNPs-K and lowest in AgNPs-M. Furthermore, the synthesized AgNPs exhibited potential for environmental remediation, with AgNPs-M exhibiting the highest removal efficiency (19.24% at 120 min) for methyl orange dye in simulated wastewater. Further, all three types of AgNPs were evaluated for the removal of methyl orange dye from the simulated wastewater, where the highest dye removal percentage was 19.24% at 120 min by AgNPs-M. Antibacterial potential of the synthesized AgNPs assessment against both Gram-positive (GPB) Bacillus subtilis (MBC23), B. cereus (MBC24), and Gram-negative bacteria Enterococcus faecalis (MBP13) revealed promising results, with AgNPs-M, exhibiting the largest zone of inhibition (12 mm) against GPB B. megaterium. Such investigation exhibits the potential of the bacteria for the synthesis of AgNPs with diverse morphology and potential applications in environmental remediation and antibacterial therapy-based synthesis of AgNPs.

The Effect of Type and Concentration of Receiving Phase on Silver Separation Efficiency by Supported Liquid Membrane Technique

The Effect of The Type and Concentration of The Receiving Phase on The Efficiency Of Silver Separation with Liquid Supported Membrane Techniques. The process of making negative x-ray films in a radiology laboratory produces liquid wastes containing various chemical compounds with the main content being Ag metal (in the form of Ag+ cations). This waste is categorized as a dangerous and toxic material. Therefore it is necessary to separate the Ag metal before it is discharged into the environment so as not to be harmful to life and the environment. One of the separation techniques that can be used is with supported fluid membrane technique (Supported Liquid Membrane, SLM). The supported liquid membrane has three important components: the feed phase containing the component to be separated, the membrane phase containing the carrier compound and the receiving phase containing the integral component. The three-phase composition determines the efficiency of the separation process. This study aims to identify the type and concentration of the receiving phase solution to improve silice metal separation efficiency by SLM technique. To obtain an efficient composition in the recipient phase was carried out by varying the type of acid received solution ie H3PO4, HNO3 and CH3COOH with respective concentrations of 0.01; 0.05; 0.10; 0.15; and 0.20 M. Measurement of metal ion concentration of Ag+ before and after transport was determined by Atomic Absorption Spectrophotometer (SSA) at wavelength 328,22 nm. Based on the result of research that type and concentration of acid solution in the receiving phase has an effected on separation efficiency. The optimum transport percentage has obtained on the used of H3PO4 receptor solution at a concentration of 0.1 M with a percentage of Transport Ag of 46.84%.

Carica papaya Crude Extracts Are an Efficient Source of Environmentally Friendly Biogenic Synthesizers of Silver Nanoparticles

Metallic nanoparticles are very useful, effective, and usually synthesized by toxic and expensive chemicals. Silver nanoparticles (AgNPs), measuring less than 100 nm, have shown promising impact in several biomedical investigations. These can inhibit microbial growth and aid in medicine administration. Six substrates of Carica papaya were used to synthesize silver nanoparticles that can limit the growth of bacteria and fungi. In this article, we report the synthesis of AgNPs from the leaf, seed, callus, peel, fruit juice, and bark of Carica papaya. AgNPs synthesized from callus showed the most promising results when tested against the growth of bacteria like Xanthomonas campestris, Erwinia carotovera, Bacillus subtilis, and fungi (Aspergillus niger and Fusarium oxysporum) when compared with other extracts’ efficacy, and the callus was regenerated from petiole and midrib explants of Carica papaya in MS basal media supplemented with NAA and Kinetin (1 + 0.5 mg/L). A ratio of 1:20 of substrate extract to 1 mM AgNO3 produced the most effective nanoparticles in terms of capping, quality, and stability when tested through surface plasmon resonance (SPR) within the 400–435 nm range. The nanoparticle sizes of all six types were measured using Image J software on micrographs of SEM at 200 nm resolution. The average diameters were analyzed through Origin software, and the finest AgNPs were observed to be synthesized from callus extract, i.e., 18.91 nm with rod-like morphology. Energy dispersive X-ray (EDX) at 2.6 keV revealed 43.38, 75.39, 70.611, 36.54, 58.57, and 45.94 percent elemental silver in AgNPs formed from the leaf, callus, juice, seed, bark, and peel extract, respectively. Silver nanoparticles synthesized from callus extract were smaller and exhibited the most effective antimicrobial potential, with the highest inhibitory zone of 19 mm against Xanthomonas campestris bacterium and up to 14 mm against Aspergillus niger fungus. Furthermore, the percentage of elemental Ag (measured through EDX) was found to be highest in the nanoparticles synthesized from callus compared to those synthesized from the leaf, seed, peel, fruit juice, and bark of Carica papaya. Hence, the callus extract is the most suitable substrate for the reduction of silver nitrate solution in 1:20 to form the finest silver nanoparticles in an effective biogenic way.

Preparation of a Novel Ag/CFOOVs Composite Catalyst and Efficient Degradation of Phenol in a H2O2-based Fenton-like System

Although CuFe2O4 has been widely used in the field of Fenton-like wastewater treatment, its ability to activate H2O2 still needs to be further improved. In this context, a novel Agx/CFOOVs (x represents the theoretical mass percentage of Ag) composite catalyst was prepared by the tartaric acid reduction method for the first time, and its degradation performance and degradation mechanism of Phenol in a H2O2-based Fenton-like system were investigated. Through a series of characterizations, the successful preparation of the catalyst was confirmed. The degradation experiment showed that the degradation rate of 50mg/L Phenol by Ag2/CFOOVs/H2O2 system was 98.55% within 15min, which was a significant improvement in the degradation efficiency compared with that of CuFe2O4 and CFOOVs. X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) confirmed the successful introduction of oxygen vacancies (OVs). Electrochemical impedance spectroscopy (EIS) showed that Ag2/CFOOVs had the lowest impedance, and the synergistic effect of OVs and Ag effectively enhanced the degradation capability of the catalysts for Phenol. The capture experiments of active species and ESR tests showed that the main active species of the Ag2/CFOOVs/H2O2 system were 1O2 and •OH. This study provides a new reference for the introduction of OVs and Ag in Fenton-like catalysts and their application to wastewater treatment.

Investigation of methods to quantify silver screen-printed onto cellulosic substrate: towards recycling of printed electronics

The continued progress in electronics technology has led to unsustainable consumption of plastic-based products containing, in their majority, natural finite metallic resources. The substitution of these plastic materials by more sustainable ones, such as cellulosic substrates, is one of many measures applied by the industry to reduce their environmental impact. In this work, due to the lack of information in the literature, a fast and accurate method to measure the amount of metal deposited onto a paper-based substrate is proposed. The development of this method will contribute to the creation of a procedure for determining the quantity of metal present in end-of-life printed electronics. The present work investigates and compares four different methodologies. Image processing and geometrical analyses presented overestimated and non-precise results for printed Ag. A third method based on gravimetric measurements presented to be more accurate compared with the previous methods. The last method based on acid leaching of the printed electronic ashes outcome to be the more precise, reliable and simpler method, and overcomes challenges associated to the printed pattern geometry and the materials used during its production. These results will provide key information for the development of a quantitative methodology to determine the percentage of Ag used in paper-based electronics that can be adapted easily by the industry. Furthermore, this method is a prerequisite for recycling processes devoted to this type of electronics after reaching their end-of-life, considering Ag as one of the major components to be separated and, further, valorized.

Eco-friendly high-rate formation of silver nanoparticles in agave inulin and its bactericidal effect against Escherichia coli

Abstract A high rate of silver nanoparticle formation, effective against the Escherichia coli (E. coli) bacterium, was obtained for the first time by means of a simple, eco-friendly, and low-cost green method in a solution of agave inulin. The study was carried out using the traditional method, in which the effects of the concentration of agave inulin, AgNO3, temperature, and pH on the synthesis were analyzed by UV-Vis spectroscopy and transmission electron microscopy (TEM). Most of the nanoparticles produced were spherical with a size less than 10 nm. In a sample with 20 mg/mL of agave inulin, 1 mM of AgNO3, T = 23°C, and pH = 12, the highest percentage of Ag+ ions available in the solution were reduced for the formation of nanoparticles in less than 40 min, whereas a sample prepared with 60 mg/mL of agave inulin, 10 mM of AgNO3, T = 23°C, pH = 12, and a storage time of 40 min showed a significant bactericidal effect on the E. coli strain. Agave inulin is a good biological compound for the formation of small, spherical silver nanoparticles. A pH of 12 favors a higher production speed of the silver nanoparticles and better use of the available Ag+ ions. In addition to this, the concentration of AgNO3 is a determining factor for increased formation of the nanoparticles necessary to bactericidal effect.

Effects of Ag content on microstructure evolution, intermetallic compound (IMC) and mechanical behaviour of SAC solder joints

SnAgCu (SAC) solder joints are widely used in electronic industry as alternative to lead free solder. The microstructure of the solder joint plays an important role in enhancing the mechanical properties of the solder joint, thus the electronic devices will have a longer lifetime. This paper studies the effects of silver (Ag) percentage on the microstructure and intermetallic compound (IMC) in Sn-Ag-Cu solder, and how the addition of Ag impacts the mechanical concepts of SAC solder joints. SAC solder joints were examined as a function of Ag3Sn precipitates (in terms of the number and size of the precipitates) and intermetallic compounds (IMCs). The microstructure morphology of the SAC samples was analyzed by using a scanning electron microscope (SEM) with back scattering mode.A quantitative analysis of number of Ag3Sn was performed for all SAC samples. The results showed that when the amount of the Ag content increased, that led to an increase in the number of Ag3Sn precipitates with an increase the eutectic area but does not affect the growth of IMC. The mechanical properties of SAC samples were enhanced significantly by increasing the Ag content.

Conductivity Enhancement of Graphene and Graphene Derivatives by Silver Nanoparticles

In this article, a facile way for the doping of graphene and graphene derivatives with silver nanoparticles at different Ag ratios is described. Ag nanoparticles were formed directly on the surface of two different graphene substrates dispersed in dimethylformamide by the reduction of Ag cations with NaBH4. A few layered graphene nanosheets (FLG) produced from graphite and reduced graphene oxide functionalized with amino arylsulfonates (f-rGO) were used as substrates. The final graphene/Ag nanoparticle hybrid in the form of solid, dense spots showed enhanced electrical conductivity, which can be attributed to the formation of conductive interconnections between the 2D nanosheets. Importantly, electrical conductivities of 20 and 167 103 S m−1 were measured for the hybrids of f-rGO and FLG, respectively, with the higher Ag percentage without an annealing process. A representative hybrid f-rGO with Ag nanoparticles was used for the development of a highly conductive water-based gravure ink with excellent printing properties.

Association Of Single Nucleotide Polymorphism With Insertion/Deletion ACE Gene Detected Using RhAmp Platform In COVID-19 And Hypertension Patients

The high activity of Angiotensin Converting Enzyme (ACE) in patients with hypertension is thought to affect the risk and severity of COVID-19. Insertion/deletion (I/D) and SNP polymorphisms of the ACE gene can affect ACE activity in the Renin-Angiotensin System (RAS). This study aims to identify linkage disequilibrium SNPs rs4331 (A/G), rs4341 (G/C), and rs4343 (G/A) with I/D polymorphisms reported in previous studies and their associations with the severity of COVID-19 with hypertension comorbid. A cross-sectional study in 2021 recruited 95 samples of COVID-19 patients from two regions representing the eastern and western parts of Indonesia. Detection of polymorphisms using rhAmp SNP showed the percentage of genotypes GG, AG, and AA at rs4331 according to genotype II, DI, and DD in polymorphism I/D (57%, 32%, and 11%). In contrast, rs4341 only showed one type of genotype (GG), and 37% of the samples were undetermined at rs4343. Based on the linkage disequilibrium, it is known that rs4331, rs1799752, and rs4343 are in strong LD (D'= 0.97 and 0.99), and rs4331 and rs1799752 can be markers of genes to replace one with another (R2= 0.957). The haplotype analysis showed a significant difference between the residents of western and eastern Indonesia (p = 0.005), whereas this was not the case with hypertension comorbidities and the severity of COVID-19. Seventeen percent of the G-I-G-G haplotypes showed moderate-severe severity, while 15% of the A-D-G-G haplotypes showed mild severity. Therefore, it can be concluded that the high I/D, rs4331, and rs4343 polymorphisms are likely co-inherited and that the G-I-G-G haplotype is associated with moderate-to-severe severity in COVID-19.

Refractive index improvement of commercial chalcogenide glasses by external doping with Ag and Pb

The refractive index of commercial chalcogenide glasses (ChGs) available in the market is generally 2.4 to 2.7, which is relatively low and has huge room for improvement. In this paper, different ratios of Ag/Pb were doped into commercial glasses by the melt-quenching method to substantially increase their refractive index. The refractive index of the commercial Ge28Sb12Se60 glass was increased from 2.6 to 3.05 by external doping with 20 atomic percentage (at%) of Ag. And the refractive index of commercially available Ge33As12Se55 glass was increased from 2.45 to 2.88 by external doping with 9 at% of Pb. These improvements effectively reduce the thickness of commercial lenses at the same radius of curvature and focal length. The physical and optical properties of commercial glasses doped with Ag/Pb in different proportions were systematically characterized.

Green synthesis of photocatalytic TiO2/Ag nanoparticles for an efficient water remediation

This work reports a green method to produce efficient photocatalytic nanopowders. Titanium dioxide nanoparticles were easily synthetized by an extract of Thymus vulgaris, and then decorated with commercial silver nanoparticles. A detailed morphological, structural, and chemical characterization was performed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) adsorption–desorption of N2, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and UV–Vis spectroscopy. The synthetized TiO2 nanoparticles showed a mean size of 10–15 nm, and had the anatase crystallographic phase. The photocatalytic efficiency of the TiO2 nanoparticles was demonstrated by the photo-degradation under UV-light irradiation of different pollutants in aqueous solution (methylene blue, diclofenac, and sodium dodecyl sulfate). TiO2 was coupled to Ag nanoparticles with different percentage in weight (from 0.25 to 3%), to investigate an eventual improvement of its photocatalytic efficiency. The best photocatalytic composite among the tested compositions was the one with the lowest Ag percentage (0.25%). Zebrafish embryo toxicity tests ruled out the toxicity of the synthetized nanoparticles. The present results offer a new, green, and easy method to prepare TiO2/Ag nanoparticles with high photocatalytic efficiency. The proposed materials are therefore promising for applications in photocatalysis, especially for wastewater remediation and reuse.

Influence of Graphene and Silver Addition on Aluminum’s Thermal Conductivity and Mechanical Properties Produced by the Powder Metallurgy Technique

The high heat dissipation of high-power electronic equipment has become a major cause of damage, especially the central processing units (CPUs) of computers and other electronic devices. Accordingly, this research aims to improve the thermal conductivity as well as the mechanical properties of aluminum (Al) by mono and hybrid reinforcements of silver (Ag) and graphene (G) so that they can be used for heat dissipation. The structures of the prepared powders were investigated using the X-ray diffraction (XRD) technique. Furthermore, the sintered composites’ microstructure, density, thermal conductivity, mechanical properties, and electrical conductivity were investigated. The results showed that adding Ag percentages led to forming the Ag2Al phase while adding graphene decreased the crystallite of the milled powder. The SEM results showed that the samples had high densification, which was slightly reduced with increasing percentages of reinforcements. Importantly, Al’s thermal conductivity and mechanical properties were significantly improved due to the addition of Ag and G reinforcements with a slight decrease in electrical conductivity. The highest thermal conductivity was observed a 278.86 W/mK in the sample containing 5 vol.% of Ag and 2.5 vol.% of G, which was improved by about 20.6%. In contrast, the highest microhardness and Young’s modulus were 39.19 HV and 71.67 GPa, which resulted in an improvement of about 30.7 and 17.8% for the sample containing 2.5 vol.% of Ag and 5 vol.% of G when compared to the Al matrix. Based on these promising findings, it is possible to infer that the objective of this study was effectively attained and that the created composites are appropriate for such applications.

Facile synthesis of reusable Ag/TiO2 composites for efficient removal of antibiotic oxytetracycline under UV and solar light irradiation

BackgroundsIn this work, Ag-doped TiO2 nanomaterials (TiAgx, where x denotes the weight percentage of Ag) were prepared using a facile one-step sol-gel technique. The combination of Ag with TiO2 promises to enhance the lifetime of photogenerated electron-hole pairs and widen the photocatalytic activity in the visible light region, leading to improved photocatalytic activity. MethodsThe synthesized materials were characterized using different analyses and afterwards applied as photocatalysts to degrade oxytetracycline (OTC) in aqueous solution under ultraviolet (UV) and solar light illumination. Significant findingsThe highest photocatalysis was achieved for TiAg2 with 99.6% OTC removal after 120-min UV irradiation. Moreover, the best OTC removal under solar light irradiation was gotten for TiAg5, of which 94.1% of OTC was removed after 180 min. Reactive species of ∙O2− radicals were presented as the dominant agents in OTC oxidization; meanwhile, ∙OH and h+ contributed to the photodegradation process. The mineralization efficiency of OTC using TiAg2 reached 59.6% after 240-min UV irradiation. Furthermore, the OTC removal of TiAg2 by photocatalysis still maintained over 97% after 5 cycles.

Antibacterial activity of multi-metallic (Ag–Cu–Li) nanorods with different metallic combination ratios against Staphylococcus aureus

ObjectiveBecause of the need to extensively study the synergistic activity of metallic nanoparticles, this study aimed to evaluate the antibacterial activity of mixed metallic nanoparticles, made by differing the weight mixing ratio. We prepared multi-metallic nanorods (NRs) by chemical reduction method, with different ratio combinations of silver Ag and copper Cu, two main batches of nanorods were produced: bimetallic mix made only of Ag–Cu, and trimetallic mix made of Ag–Cu and lithium Li, AgCu NRs and AgCuLi NRs respectively. NaOH was used in the synthesis for the co-reduction of salt precursors. Ag percentage was varied from 10 to 90% in bimetallic NRs but in the trimetallic NRs, which has a fixed ratio of Li (10%), the percentage of silver precursor was from 10 to 80%. The presence of metals was confirmed by energy dispersive X-rays (EDX) analysis. Ion release was detected using inductively coupled plasma spectrometer (ICP) and the values showed that NRs are effective source for ion supply for up to 24 h. The antibacterial activity of metallic NRs was tested against Staphylococcus aureus using Bauer Kirby method.ResultsThe bi-synergistic mix of Ag and Cu generates more ions than the tri-synergistic mix of Ag, Cu, and Li. Nevertheless, the later was more efficient and showed higher antibacterial activity at lower concentrations. This effect is less likely to be attributed to modality of ion release. Indeed, the results of our work suggest that besides ion release, alloyed nanorods themselves are toxic and the trimetallic mix exhibited more biocidal activity, specifically at Ag salt concentrations of 30%, 50% and 70%.

Facile fabrication of plasmonic Ag modified CaTiO3: For boosting photocatalytic reduction of Cr6+ and antimicrobial study

CaTiO3 was synthesized by a simple sol–gel method followed by the decoration of different weight percentages of Ag on the surface of the CaTiO3 wetness impregnation method (AgCTO). Characterization of the prepared catalyst (XRD, FTIR, SEM, HRTEM, UV–VIS DRS, PL) showed a better result for morphological, optical, and also towards its activity in wastewater remediation. X-ray diffraction study delineates CaTiO3 perovskite possesses an orthorhombically distorted structure and after the distribution of Ag on the surface of CaTiO3 maintains crystallinity. The loading of Ag reduces the difference in band gap from 2.8 to 2.10 eV and extends the photocatalyst towards the visible range. This is mostly caused by the localized surface plasmon resonance effect (LSPR). The Schottky junction formed at the CaTiO3 and Ag contact effectively facilitates electron transport. This results in a reduction in the photocatalytic activity's recombination of photoinduced electrons and holes. Presence of Silver also showed good antimicrobial activity against gram-negative bacteria Salmonella typhi and Shigella flexneri because it easily makes holes in the bacterial membrane. However, the catalyst is environmentally benign and can be reutilized for environmental sustainability.