Synthesis Of Ag Nanoparticles Research Articles

Green synthesized AgNPs as a probe for colorimetric detection of Hg (II) ions in aqueous medium and fluorescent imaging in liver cell lines and its antibacterial activity

The present research aimed at green synthesis of Ag nanoparticles (AgNPs) based colorimetric sensor using persimmon leaf extract (PLE) for selective detection of mercuric ion (Hg2+). Optimization of reaction conditions viz. pH, concentration of PLE, time was done and further AgNPs were characterized using UV, IR, FE-SEM, EDX, XRD and TEM analysis. The developed AgNPs were evaluated for the selective colorimetric detection of Hg2+ in aqueous medium and fluorescence imaging of Hg2+ ions in liver cell lines. Later, the antibacterial activity of AgNPs was performed against S. aureus and E. coli. The findings of the study revealed that PLE mediated AgNPs exhibited notable limit of detection up to 0.1 ppb, high efficiency, and stability. The antibacterial study indicated that developed AgNPs has impressive bacterial inhibiting properties against the tested bacterial strains. In conclusion, developed biogenic AgNPs has high selectivity and notable sensitivity towards Hg2+ ions and may be used as key tool water remediation.Graphical abstract

Plasmon-driven substitution of 4–mercaptophenylboronic acid to 4-nitrothiophenol monitored by surface-enhanced Raman spectroscopy

Plasmon-driven reactions on plasmonic nanoparticles (NPs) occur under significantly different conditions from those of classical organic synthesis and provide a promising pathway for enhancing the efficiency of various chemical processes. However, these reactions can also have undesirable effects, such as 4-mercaptophenylboronic acid (MPBA) deboronation. MPBA chemisorbs well to Ag NPs through its thiol group and can subsequently bind to diols, enabling the detection of various biological structures by surface-enhanced Raman scattering (SERS), but not upon its deboronation. To avoid this reaction, we investigated the experimental conditions of MPBA deboronation on Ag NPs by SERS. Our results showed that the level of deboronation strongly depends on both the morphology of the system and the excitation laser wavelength and power. In addition, we detected not only the expected products, namely thiophenol and biphenyl-4,4-dithiol, but also 4-nitrothiophenol (NTP). The crucial reagent for NTP formation was an oxidation product of hydroxylamine hydrochloride, the reduction agent used in Ag NP synthesis. Ultimately, this reaction was replicated by adding NaNO2 to the system, and its progress was monitored as a function of the laser power, thereby identifying a new reaction of plasmon-driven −B(OH)2 substitution for –NO2.

Green synthesis of silver nanoparticles decorated on graphene oxide for crystal violet dye removal

In this study, we demonstrate a facile and environmentally benign method for the synthesis of Ag nanoparticles using a green reducing agent and their subsequent deposition onto GO sheets. The synthesized GO@Ag nanocomposite was characterized using various analytical techniques such as FTIR, XRD, FESEM, EDX and BET. The results confirmed the successful formation of cubic Ag nanoparticles with diameter 30–40 nm on the GO surface. The theoretical surface area of GO@Ag was found to be 89 m2/g. The adsorption efficiency of GO@Ag nanocomposite toward CV dye was evaluated through batch adsorption experiments. The above experimental results revealed that CV adsorption on to the GO@Ag surface was pH dependent and maximum adsorption capacity was found to be 48.78 mg/g at pH = 8. The adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models, indicating monolayer adsorption with chemisorption as the rate-limiting step. Furthermore, the recyclability and stability of the nanocomposite were assessed through multiple adsorption-desorption cycles, demonstrating its potential for practical applications in wastewater treatment for the removal of cationic dyes. The mechanism of CV adsorption on to the GO@Ag surface mainly involves electrostatic attraction and π-π interaction.

A Catalytic Reduction of 4-Nitrophenol Utilizing Bimetallic CuO-Co3O4 Nanoparticles Synthesized via Wrightia tinctoria Extract: A Green Approach

In this investigation, copper oxide (CuO), cobalt oxide (Co3O4) and bimetallic copper oxide-cobalt oxide (CuO-Co3O4) nanoparticles were synthesized using an aqueous extract of Wrightia tinctoria leaves and characterized through UV-Vis, FT-IR, XRD, TEM and zeta potential analyses. The FT-IR analysis identified that specific phytoconstituents are responsible for the reduction and capping agents in nanoparticle synthesis. TEM analysis determined size and shape and zeta potential analysis assessed stability. The CuO and Co3O4 NPs, synthesized through an eco-friendly approach, were employed for 4-nitrophenol reduction with sodium borohydride. The reaction rate, was computed at 1 × 10-4 s-1, which indicated the pseudo-first-order kinetics. The synthesis of 4-aminophenol was also successfully acheived demonstrated that the excellent catalytic activity of CuO, Co3O4 and CuO-Co3O4 nanoparticles as catalysts.

Green Synthesis and Antimicrobial Study on Jujube Seed Extract Functionalized Ag Nanoparticles

AbstractGreen synthesis of Ag nanoparticles (AgNPs) by using the plant extract is a very important strategy to gain efficient antimicrobial agents with strong antimicrobial activity and low toxicity. In this study, jujube seed extract (JSE) is utilized to green synthesis of AgNPs by both hydrothermal process and solution‐based approaches. UV–vis absorption spectroscopy and infrared spectroscopy (FTIR) spectra confirm that jujube seed extract functionalized Ag nanoparticles are formed by both approaches and jujube seed extract covered on the surface of Ag nanoparticles. Transmission electron microscopy (TEM) images indicate that the JSE‐AgNPs are spherical with the average diameter of 17.7 and 14.2 nm for the hydrothermal process and solution‐based approaches, respectively. X‐ray diffraction (XRD) results indicate that the JSE‐AgNPs prepared by both approaches have face‐centered cubic crystal structure. The antimicrobial activity test reveals that minimum inhibitory concentrations (MIC) of JSE‐AgNPs by the solution‐based method are 62.5, 125, and 62.5 µg mL−1 against Escherichia coli, Staphylococcus aureus, and Candida albicans, respectively. These results imply that the JSE‐AgNPs have potential to be developed as efficient antimicrobial agents.

Low temperature one-step synthesis of Ag nanoparticles on BaTiO3 for synergistic piezo-photocatalytic properties

It is a major constraint that complex synthesis methods limit the application of catalysts. Herein, Ag/BaTiO3 catalyst is synthesized via a facile method, which demonstrates the outstanding catalytic properties. Investigations reveal that Ag-loading BaTiO3 could increase carrier concentration, reduce the electronic impedance and enhance carrier’s separation efficiency under ultrasonic vibration, leading to superior piezocatalytic performance. Therefore, Ag/BaTiO3 catalyst presents the high degradation efficiency of 95.4 % in 50 min for RhB dye solution at light illumination and ultrasonic vibration. Moreover, when Ag content is 0.33 %, the degradation ratio of the sample still remains 81.9 % after 5th cycles, which indicates Ag/BaTiO3 catalyst has good stability. This work provides a novel and easy implement strategy for designing high performance catalysts, and could be extended to other catalytic material.

Selective Flocculation and H2O2-Free Oxidative Etching-Based Synthesis of Highly Monodisperse Ag Nanospheres for Uniform Quantum Dot Photoluminescence-Enhancing Plasmonic Cavity Applications.

Ag nanoparticles have garnered significant attention for their excellent plasmonic properties and potential use as plasmonic cavities, primarily because of their intrinsically low ohmic losses and optical properties in the visible range. These are particularly crucial in systems involving quantum dots that absorb light at low wavelengths, where the need for a high threshold energy of interband transitions necessitates the incorporation of Ag nanostructures. However, the synthesis of Ag nanoparticles still encounters challenges in achieving structural uniformity and monodispersity, along with chemical stability, consequentially inducing inconsistent and poorly reliable optical responses. Here, we present a two-step approach for synthesizing highly uniform spherical Ag nanoparticles involving depletion-induced flocculation and Cu(II)-mediated oxidative etching. We found that the selective flocculation of multitwinned Ag nanocrystals significantly enhances the uniformity of the resulting Ag nanostructures, leaving behind only single-crystalline and single-twinned nanostructures. Subsequent oxidative etching, in which cupric ions are directly involved in the reaction, was designed based on Pourbaix diagrams to proceed following thermodynamically favorable states and circumvent the generation of reactive chemical species such as H2O2. This leads to perfectly spherical shapes of final Ag nanoparticles with a synthetic yield of 99.5% and additionally reduces the overall reaction time. Furthermore, we explore the potential applications of these monodisperse Ag nanospheres as uniform plasmonic cavities. The fabricated Ag nanosphere films uniformly enhanced the photoluminescence of InP/ZnSe/ZnS quantum dots, showcasing their capabilities in exhibiting consistent plasmonic responses across a large area.

Recent Advancements and Unexplored Biomedical Applications of Green Synthesized Ag and Au Nanoparticles: A Review.

Green synthesis of silver (Ag) and gold (Au) nanoparticles (NPs) has acquired huge popularity owing to their potential applications in various fields. A large number of research articles exist in the literature describing the green synthesis of Ag and Au NPs for biomedical applications. However, these findings are scattered, making it time-consuming for researchers to locate promising advancements in Ag and Au NPs synthesis and their unexplored biomedical applications. Unlike other review articles, this systematic study not only highlights recent advancements in the green synthesis of Ag and Au NPs but also explores their potential unexplored biomedical applications. The article discusses the various synthesis approaches for the green synthesis of Ag and Au NPs highlighting the emerging developments and novel strategies. Then, the article reviews the important biomedical applications of green synthesized Ag and Au NPs by critically evaluating the expected advantages. To expose future research direction in the field, the article describes the unexplored biomedical applications of the NPs. Finally, the articles discuss the challenges and limitations in the green synthesis of Ag and Au NPs and their biomedical applications. This article will serve as a valuable reference for researchers, working on green synthesis of Ag and Au NPs for biomedical applications.

Green Synthesis of Ganoderma Lucidum-Mediated Silver Nanoparticles and its Microbial Activity against Oral Pathogenic Microbes: An In Vitro Study

ABSTRACT Nanotechnology is developing into a fast-expanding discipline with applications in science and technology, and nanostructures are a crucial research tool in many fields. Due to their remarkable electrical, optical, magnetic, catalytic, and pharmacological capabilities, metal and metal oxide nanoparticles (NPs) have drawn study interest. Natural elements (plants, microorganisms, fungi, etc.) are utilized in a chemical-free, environmentally benign way to synthesize metals and metal oxides. The optical, electrical, and antimicrobial qualities of silver nanoparticle (AgNP) make them a popular choice. More than 200 active ingredients, including water-soluble, organic-soluble, and volatile chemicals, are found in Ganoderma. The main components are polysaccharides, adenosine, and terpenoids, each of which has exceptional therapeutic properties. This article explains the synthesis of Ag NPs by Ganoderma lucidum and tests the antibacterial effectiveness for use in biological applications.

Green synthesis of Ag nanoparticles from Verbascum insulare Boiss. and Heldr.: Evaluation of antimicrobial, anticancer, antioxidant properties and photocatalytic degradation of MB

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.

Bespoke Metal Nanoparticle Synthesis at Room Temperature and Discovery of Chemical Knowledge on Nanoparticle Growth via Autonomous Experimentations

AbstractThe optimization of nanomaterial synthesis using numerous synthetic variables is considered to be an extremely laborious task because conventional combinatorial explorations are prohibitively expensive. In this work, an autonomous experimentation platform developed for the bespoke design of metal nanoparticles (NPs) with targeted optical properties is reported. This platform operates in a closed‐loop manner between the batch synthesis module of metal NPs and the UV–vis spectroscopy module, based on the feedback of the AI optimization modeling. With silver (Ag) NPs as a representative example, it is demonstrated that the Bayesian optimizer implemented with the early stopping criterion can efficiently produce Ag NPs at room temperature precisely possessing the desired absorption spectra within only 200 iterations (when optimizing among five aqueous synthetic reagents). In addition to the outstanding material developmental efficiency, the analysis of synthetic variables further reveals a novel chemistry involving the quantitative effects of citrate in Ag NP synthesis. The amount of citrate is key to controlling the competition between spherical and plate‐shaped NPs and, as a result, affects the shapes of the absorption spectra as well. This study highlights both capabilities of the platform to enhance search efficiencies and to provide novel chemical knowledge by analyzing datasets accumulated from autonomous experimentations.

Biosynthesis of Silver Nanoparticles at Various pH values and their Applications in Capturing Irradiation Solar Energy.

Metallic nanoparticles (NPs), in general, are able, due to the high surface area per unit volume, to absorb the maximum incoming light flux through the vicinity of plasmonic structures and then provide local heating. Thus, silver (Ag) NPs has been used to generate heat and increase the temperature of water from solar radiation energy. The optimal plasmonic heating generation can be obtained as soon as the wavelength of the light source is close to the plasmonic resonance wavelength of Ag NPs. Ag NPs have been fabricated through a straightforward, cheap, as well as environmentally friendly approach. In this study, Salix babylonica L., weeping willow leaf extract has been utilized as a reducing, capping, and stabilizing agent, without using any other toxic materials. The importance of this study lies in the generation of hot electrons, which can be obtained by collecting the solar spectrum near the infrared and infrared regions, which cannot be obtained by the conventional photocatalytic devices. Numerous characterization techniques such as; UV-Vis, FT-IR spectroscopy, X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis were used to study the optical, chemical, structural, morphological, properties of the Ag NPs. The impact of pH on the properties of Ag NPs and their performance to generate heat during solar irradiation have been investigated intensively. This study showed that the synthesized Ag NPs with pH value 12 is the optimum condition and can increase the temperature of water dramatically. An evaluation of the current patents displays that the field of green synthesis Ag NPs utilizing plant extracts is a vital field and produces rather stable, safe and effective Ag NPs. The novelty of this patent is that Ag NPs can be synthesized from a one-pot reaction without using any exterior stabilizing and reducing agent, which is not conceivable by means of the existing processes. This study, also, is rare and distinctive, and it demonstrates that even a slight quantity of the Ag NPs is significantly raising the temperature of water effectively.

Combustion Synthesis of Ag Nanoparticles and Their Performance During NaBH4 Hydrolysis

AbstractDue to their tremendous industrial, environmental, and biological applications, research focusing on the synthesis and applications of silver nanoparticles (Ag NPs) has attracted increased interest from researchers over the past two decades. Their structural as well as textural properties can be easily tuned depending on the synthesis protocol utilized. Combustion synthesis has received increased attention as a one-pot route for the synthesis of a wide spectrum of nanomaterials. In this study, we present the results of synthesizing Ag NPs employing urea as a combustion fuel. The effect of the temperature of calcination on the formation and structural features of Ag NPs has been checked over the 400–700 °C temperature range. The characterization of the synthesized Ag NPs has been performed using XRD, SEM, TEM, and XPS techniques. It was found that Ag NPs, with a crystallite size of 40 nm, start to form at around 400 °C. Conducting the calcination at the 500–700 °C range results in the persistence of the obtained Ag NPs. Moreover, the obtained nanomaterials are characterized by a membrane-like morphology. The activity performance of the synthesized Ag NPs was examined for the hydrolysis of sodium borohydride (NaBH4) over a temperature range of 35–50 °C. Increasing the calcination temperature has led to a decrease in the activity of the Ag NPs during the NaBH4 hydrolysis. Graphical Abstract

Coproduction of bio-microbicide and silver nano-microbicide mediated by endospore-forming Bacillus and their synergetic control of plant disease

BackgroundOne-pot synthesis of metal nanoparticles under ambient temperature and pressure using reducing and stabilizing materials from microbes is energy-effective and ecofriendly, but upstream extraction of biological raw materials and downstream purification of nanoparticles from bioreactors are laborious and expensive. To simplify the productive process for using metal nanoparticles as microbicides to control plant pathogens, we use an endospore-forming Bacillus biocontrol agent to produce the nano-microbicide and use the bacterial raw materials as bio-microbicides together with the nano-microbicide.ResultsBacillus cells at the stationary phase form endospores and tolerate Ag+ and Ag nanoparticles (AgNPs), while the cell-free culture supernatant (CFCS) mediates the synthesis of AgNPs. AgNPs produced from the Bacillus culture and CFCS show similar physical, chemical, and electrical characteristics, and bactericidal and anti-biofilm activities. Moreover, the diluted products effectively protect the kiwifruit leaves from the infection of the pathogen Pseudomonas syringae pv. actinidiae.ConclusionsThis coproduction of bio-microbicide and nano-microbicide is a totally green one-pot synthesis process without extraction and purification and without production of waste and can be easily scaled up using the existing fermentation processing of Bacillus biocontrol agents. The application of the synergistic bio-microbicide and nano-microbicide can effectively control the bacterial canker disease of kiwifruit plants.Graphical

WASTE EGGSHELLS AS CATALYSTS: AN ENVIRONMENTALLY-FRIENDLY APPROACH

Sustainability is crucial for the survival of mankind, ecosystem for the development of society. There have been huge amount of waste have been dumped which creates pollutions. Hence, from Green chemistry perspective it is a protocol to design heterogeneous catalysts which can yield products from waste products with minimization of wastes pollution with environmentally friendly heterogeneous catalytic process for the developed environmentally friendly products with longevity. Such green synthesized heterogeneous catalysts will replace the existing homogeneous process to heterogeneous catalysts being developed from waste materials. This abstract highlight key aspects on the preparation of heterogeneous catalysts derived from waste materials such as egg shell, rice husk for synthesis of Ag Nanoparticles developed, which can applied for biomass conversions, to environmental remediation, heterogeneous catalysts for organic transformations. These egg shell CaO catalysts are characterized using analytical techniques, such as: X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Thermogravimetric-Differential Thermal Analyzer (TG-DTA), Scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area, which gives its complete picture of its structure, porosity, morphology, thermal stability, reusability, and activity of catalysts. Hence heterogeneous catalysts developed from egg shell wastes and medical plants will become increasingly popular since two decades. Since, the egg shell waste is developed into egg shell CaO catalysts for cleaner, reusable, eco-friendly catalysts for economic growth for Namibia and other developing and underdeveloped countries.

Antimicrobial Activity of Hydrophilic Sealants incorporated with Green Synthesized Silver nanoparticles-An invitro Study

Background: Dental caries formation is highly prevented by applying pit and fissure sealant but was associated with microleakage and secondary caries formation. Aim and Objectives: To synthesize novel pit and fissure sealant with green synthesized silver nanoparticles and evaluation of antibacterial activity against Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans. Materials and Methods: Green synthesis of silver nanoparticles was done using beetroot, characterized using FTIR (Fourier transform infrared), EDAX (Energy Dispersive X-ray Analysis), and Scanned Electron Microscope Analysis. A novel pit and fissure sealant was made by incorporating synthesized Ag nanoparticles and hydrophilic nature from Ultra seal XT Hydro. Using amoxicillin as a control, an agar well diffusion method was used to conduct an antimicrobial test for a new sealant against Staphylococcus aureus, Streptococcus mutants, Enterococcus faecalis, and Candida albicans in Muller Hinton Agar for each organism. Result: Zone of inhibition was measured, showing statistically significant antimicrobial activity against Streptococcus mutans with the ZOI value at concentration of Ag nanoparticles in sealant material. Conclusion: Novel Hydrophilic pit and fissure sealant with Ag nanoparticles are potentially antibacterial against the cariogenic microorganism. Thus, it can be utilized for the better efficiency of topical pit and fissure sealant preventive therapy.

Synthesis of Silver Nanoparticles in <i>Psidium Guajava</i> (Guava) Leaf Extract for Antibacterial Textiles

Textiles, an integral part of everyday clothing, are exposed to varied sources of dirt, leading to bacterial accumulation and cross-contamination. As such, antibacterial textile has become a widespread research interest. One method to create antibacterial textiles is the incorporation of silver nanoparticles (NPs) due to their efficacy in stopping multi-drug resistant (MDR) bacteria. However, most synthesis techniques in producing silver NPs are complex and expensive. Guava leaf extracts (GE) have a high quantity of metabolites and carbohydrates that can reduce and stabilize silver (Ag) ions. Guava leaves also have an innate antimicrobial property, making them highly compatible with biomedical applications. This study synthesized Ag NPs using Ag nitrate and Ag acetate as Ag precursors and guava leaves extract as reducing agents to create an antimicrobial fabric. The green synthesis successfully produced spherical Ag NPs with mean diameters around 24 nm. Energy-dispersive X-ray spectroscopy (EDX) analysis confirmed the formation of Ag NPs after the reaction. The Ag NPs were deposited on cotton fabrics, which showed significant antibacterial activity even after 5 washings. Generally, the Ag NPs synthesized with larger amounts of guava leaves extract showed larger clearing zones, indicating better antimicrobial activity.

Green synthesis and characterization of silver doped ZnO particles

Green Synthesis is a chemical-free, economic, efficient, eco-friendly, and less time-consuming technique for the production of various nanoparticles. In the present study, green synthesized silver doped ZnO particles are synthesized. Silver nanoparticles are synthesized using Neem leaves and Silver salt (Silver Nitrate, AgNo3). Leaves extract act as a reducing agent for this synthesis. EDAX confirms the formation of Ag nanoparticles and ZnO particles. ZnO nanoparticles were successfully synthesized by the co-precipitation method, zinc acetate dehydrate and sodium hydroxide was used as precursor material. The green synthesized Ag nanoparticles are doped with ZnO. The synthesized particles were then characterized through XRD and UV–Vis spectrophotometry. The values of interplanar spacing and lattice parameters obtained were consistent with its standard values. The band gap of ZnO nanoparticles got reduced with doping Ag nanoparticles.

Biofilm-engineered fabrication of Ag nanoparticles with modified ZIF-8-derived ZnO for a high-performance supercapacitor

The particle size, pore structure, and surface area of nanomaterials are critical characteristics that govern their effectiveness in energy storage applications. In addition, as the accessibility of the surface to ions or reactants has a significant impact on the performance of the supercapacitor, thus the properties of designed nanostructures are essential and need to be considered. In this study, a ZnO-based nanomaterial with a high surface area and electronic conductivity was synthesized by combining the thermal treatment of a zeolitic imidazolate framework-8 (ZIF-8) with a biofilm-assisted surface modification method. A nanocomposite of ZnO and carbon (ZnO/C) was prepared by the systematic N2/O2 thermal treatment of ZIF-8. The ZnO/C composite underwent additional modification through the direct synthesis of Ag nanoparticles (Ag@ZnO/C) on the ZnO/C surface.An electrochemically active biofilm (EAB) was used as the reducing tool to synthesize the Ag nanoparticles. The final product, Ag@ZnO/C, was used as the electrode in a supercapacitor. Ag@ZnO/C exhibited a specific capacitance of 368.4C g−1 (921 F g−1) at a current density of 1 A g−1, which was remarkably higher than that of ZnO/C (383.5 F g−1). The cyclability of Ag@ZnO/C was also evaluated, demonstrating a 95 % capacity retention over 9000 cycles. The significantly enhanced surface area and electronic conductivity of Ag@ZnO/C resulted in an excellent supercapacitor performance.

Green synthesis of Ag nanoparticle supported on graphene oxide for efficient nitrite sensing in a water sample

Water is essential for conserving biodiversity, ecology, and human health, but because of population growth and declining clean water supplies, wastewater must be treated to meet demand. Nitrite is one of the contaminants in wastewater that is well-known. It is crucial to identify nitrite since it can be fatal to humans in excessive doses. Utilizing a straightforward and effective electrochemical sensor, nitrite in actual water samples may be determined electrochemically. The sensor is created by coating the surface of a GC electrode with a thin layer of graphene oxide (GO), followed by a coating of silver nanoparticles. The modified electrode reached a linear detection range of 1–400 µM. thus, the activity of the electrode was investigated at different pH values ranging from 4 to 10 to cover acidic to highly basic environments. However, the electrode recorded limit of detection (LOD) is equal to 0.084, 0.090, and 0.055 µM for pH 4, 7, and 10, respectively. Additionally, the electrode activity was utilized in tap water and wastewater that the LOD reported as 0.16 and 0.157 µM for tape water and wastewater, respectively.