Average Diameter Of Nanoparticles Research Articles

Fabrication of plasmonic junction diodes based on Ag@ZnO core-shell nanostructures

In this study, Ag nanoparticles and Ag@ZnO core–shell nanostructures were prepared using the wet chemical method and these nanostructures were used for Ag@ZnO/p-Si diode fabrication. Structural, morphological, and optical characterization techniques were applied for Ag@ZnO core–shell NPs prepared by using different molarity of precursor ZnCl2 (10 mM, 20 mM, 30 mM) and showed that the effect of increasing precursor amount on these physical properties of nanoparticles is important. For Ag@ZnO, transmission electron microscopy shows an average diameter of Ag nanoparticles was 51.32 nm and Ag@ZnO core–shell nanostructures were found to be between 31 and 92 nm. The UV-visible absorbance also shows significant plasmonic resonance for NPs, with a slight red shift increasing precursor molarity. The peaks are found to be from 412 nm to 432 nm. This redshift in surface plasmon absorption of Ag@ZnO core–shell structures are consistent with XPS survey. The current–voltage (I-V) characteristic curves of heterojunction diodes were taken in the dark and at room temperature, and it was observed that they showed a rectifying feature. Ideality factor and barrier height values have been found between 2.14 and 3.87, and 0.56 and 0.78, respectively. The results revealed that Ag@ZnO was successfully synthesized and can be used in rectification applications.

Synthesis of Copper Oxide Nanostructures by Ar Plasma Jet and Study of Their Structural and Optical Properties

This paper used argon plasma jets to prepare CuO nanostructures. Several techniques, including UV–Vis spectroscopy, X-ray diffraction (XRD), X-ray energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), were used for the characterization of the prepared CuO nanoparticles. UV–Vis spectroscopy analysis confirmed that the CuO nanostructures have an energy band gap of 2.7 eV. The XRD analysis showed that the CuO nanostructures have an average crystallite size of 36 nm. Furthermore, the results of the EDX examination demonstrated the creation of CuO nanostructures of high purity. The scanning electron microscope was used to analyze the surface morphology, showing a high agglomeration rate. According to SEM analysis, the average diameter of CuO nanoparticles was 10 nm.

Thiol-functionalized mesoporous silica-embedded AuNPs with highly sensitive substrates for surface-enhanced Raman scattering detection

Surface-enhanced Raman spectroscopy (SERS) provides a fast, simple, and label-free approach that can directly detect various analytes attached to SERS substrates and provide qualitative and quantitative information based on the SERS spectra of the analyte. The signal enhancement provided by noble metal particles allows us to achieve high sensitivity and good stability even at low concentrations in water quality testing. Over the past decade, SERS has become increasingly popular in the detection field, highlighting its significant application potential. However, the signal enhancement of single AuNPs is inferior to that of AgNPs, but we can achieve an overall enhancement by uniformly arranging multiple AuNPs. The hot-spot effect, which is crucial for Raman signal enhancement, occurs only when NMNPs are within a specific distance. However, when noble metal particles come into contact with each other, the enhancement effect of the hot spot disappears. Therefore, in this study, AuNPs@MPS-SH substrates with surface-enhanced Raman scattering (SERS) activity were successfully synthesized by immobilizing AuNPs on thiol-functionalized mesoporous silica (MPS-SH). MPS nanospheres with tailored pore size and surface-bound -SH groups were synthesized for the controlled embedding of Au nanoparticles (AuNPs). By adjusting the ratio of reactants, uniform AuNP dispersion and strong MPS-AuNP interactions were achieved. This optimized structure creates localized surface plasmon resonance (LSPR) hotspots, significantly enhancing the surface-enhanced Raman scattering (SERS) effect for ultrasensitive analyte detection. Transmission electron microscopy (TEM) revealed that the average diameter of MPS nanoparticles is 260 nm, with a pore size of 8 nm. Optimal Raman enhancement was achieved at an AuNPs concentration of 2.6 × 1018 particles/mL. The lowest detection limit concentration for Rhodamine 6G was below 10−6 M, while for uremic toxin (urea) it was below 10−3 M. The ability to directly detect low concentrations by mixing with the analyte demonstrates the ultra-high sensitivity and label-free detection potential of this study in the fields of water quality and disease detection.

Evaluating the efficiency of silver nanoparticles prepared using <i>Pseudomonas fluorescens</i> and <i>Bacillus thuringiensis</i> subsp. <i>tenebrionis</i> in controlling eggs and adults of <i>Callosobruchus maculatus</i> (F.) (Coleoptera: Bruchidae)

This study aimed to evaluate the efficiency of silver nanoparticles (AgNPs) which are prepared biologically by two bacterial species, Bacillus thuringiensis tenebrionis (Btt) and Pseudomonas fluorescens (P.f) to control southern cowpea beetle insect, Callosobruchus maculatus. Many features of the prepared nanoparticles were examined, and the results obtained showed that the highest absorption value of AgNPs was at 262 nm. Whereas the results of FTIR analysis showed that several compounds played a role in the silver ions reduction process, which included alcohol, alkane, primary amine, and amine group. The scanning electronic microscopic images showed that the average diameter of nanoparticles which was created by P.f was 48.52 nm, while it was 56.08 nm for the nanoparticles prepared by Btt. The study showed no significant differences between the activity of both AgNP types against C. maculatus eggs, while a significant preference was recorded for the activity of Btt AgNPs against the C. maculatus adults. The highest percentage of unhitched eggs was 53.8% recorded at 3000 ppm concentration, while Btt AgNPs gave 59.6% at 3000 ppm. The highest mortality rate of the adults who were treated by Btt AgNPs was 58.8 % at 3000 ppm concentration, while it was recorded 50% at 3000 ppm with P.f AgNPs treatment. The current study demonstrates the efficiency of biologically prepared AgNPs in controlling C. maculatus insect life stages, which encourages using of these nanoparticles as a modern strategy in management of insect pests.

Microstructure, wear and corrosion resistances of Ni–ZrO2–CeO2 nanocoatings

This study focused on the fabrication of Ni, Ni–ZrO2 and Ni–ZrO2–CeO2 nanocoatings using ultrasonic pulse electrodeposition. The research delved into examining the surface morphology, microhardness, abrasion, and corrosion resistance of these coatings. The results indicated that the Ni coatings displayed coarse grains and an irregular structure. Among the three, the Ni–ZrO2–CeO2 nanocoatings exhibited the most dense, flat and fine microstructure among all three coatings, and the average diameters of Ni grains, ZrO2 and CeO2 nanoparticles were 68.6 nm, 21.1 nm and 23.4 nm, respectively. The Ni, Ni–ZrO2, and Ni–ZrO2–CeO2 nanocoatings displayed high micro-hardness values, measuring an average of 363.1 Hv, 421.6 Hv, and 543.8 Hv, respectively. Moreover, the friction coefficient of Ni–ZrO2–CeO2 nanocoatings was approximately 0.31. When exposed to a 3.5 wt% NaCl solution at room temperature, the Ni–ZrO2–CeO2 nanocoatings displayed minimal corrosion damage, exhibiting the lowest corrosion rate of 0.06 mm/year compared to the other coatings. The incorporation of ZrO2 and CeO2 nanoparticles in the Ni–ZrO2–CeO2 coating led to grain size reduction and a more uniform, compact microstructure, contributing to enhanced corrosion resistance when compared to both Ni and Ni–ZrO2 coatings.

Photo- and X-ray Induced Cytotoxicity of CeF3-YF3-TbF3 Nanoparticle-Polyvinylpyrrolidone-"Radachlorin" Composites for Combined Photodynamic Therapy.

The Ce0.5Y0.35Tb0.15F3 nanoparticles with a CeF3 hexagonal structure were synthesized using the co-precipitation technique. The average nanoparticle diameter was 14 ± 1 nm. The luminescence decay curves of the Ce0.5Y0.35Tb0.15F3 nanoparticles (λem = 541 nm, 5D4-7F5 transition of Tb3+) conjugated with Radachlorin using polyvinylpyrrolidone coating as well as without Radachlorin were detected. Efficient nonradiative energy transfer from Tb3+ to the Radachlorin was demonstrated. The maximum energy transfer coefficients for the nanoparticles conjugated with Radachlorin via polyvinylpyrrolidone and without the coating were 82% and 55%, respectively. The average distance between the nanoparticle surface and Radachlorin was R0 = 4.5 nm. The best results for X-ray-induced cytotoxicity were observed for the NP-PVP-Rch sample at the lowest Rch concentration. In particular, after X-ray irradiation, the survival of A549 human lung carcinoma cells decreased by ~12%.

Performance of high sensitive heterojunction CuS/porous silicon photodetector

In this work, copper sulfide (CuS) nanostructure was deposited on a porous silicon wafer for the visible light by spray pyrolysis method. Through this, a series of devices were suggested as a part of the deposit concentration of CuS on n-type porous silicon. Simultaneously, the physical features of the attained film were illustrated. FESEM exhibited that the average nanoparticle diameter increased with the concentration of CuS at orientation (100) and was found to be 47.84 nm, 56.36nm and 71.32nm, while the average diameter at (111) orientation was found to be 37.64 nm, 41.46nm, 55.22 nm of 0.1, 0.3 and 0.5M respectively. In addition to the atomic force microscope (AFM) showed the roughness and uniformity of the CuS/PSi fabricated decreased with increasing concentration of CuS, In detail, the attained photo-responsivity and specific detectivity were observed to be 210 mW/A, 340 mW/A and 3×1010 Jones, 4.2×1010 Jones at orientation (100 )using concentration of 0.1M and 0.5M respectively . On the other hand, the photo-responsivity and specific detectivity were observed to be 260 mW/A, 380 mW/A and 1.8 ×1010 Jones, 4.5×1010 Jones at orientation (111) using concentrations of 0.1M and 0.5M respectively. The presented work shows a substitutional system for an economical and environmentally friendly optoelectronic scheme. The photo-responsive considered to be in a positive linear relationship with the used concentration.

Green Synthesis of Copper Nanoparticles Using Leaf Extract of Phyllanthus niruri Lin. and Study of Its Antimicrobial Activity

Abstract: Nanoscience and Nanotechnology are the study and application of extremely small things and can be used across all the other science fields such as chemistry, biology, physics and engineering. Green synthesis of nanoparticles using plant extract is a promising and ecofriendly approach, often yielding particles with unique properties. The present study deals with biosynthesis, characterization and antimicrobial activity. Of copper sulphate nanoparticles using the leaf extract of Phyllanthus niruri. In this report, aqueous phase green synthesis of specifically copper sulphate nanoparticles using leaf extract (both fresh and dry leaf) aqueous leaf extract of leaf was used for the synthesis of nanoparticles. The synthesised nanoparticles of copper sulphate were confirmed by color change when 25ml of 1% aqueous copper sulphate solution was added to 5ml og plant extract. The synthesised nanoparticles were charecterised by UV-Visible spectroscopy, SEM (Scanning Electron Microscopy), and XRD (X-Ray Diffraction). The UV-VIS spectroscopy showed the absorption peak at 378nm for fresh leaf and 376nm for dry leaf. SEM was used to study the morphological features that was predominately spherical and aggregated into large structure with not welldefined morphology and the size347nm,358nm,400nm,457nm, for fresh leaf 1.13µm,1.14µm,771nm,935nm for dry leaf. XRD using this the particle size and nature of nanoparticle was found the average diameter of copper nanoparticles is 12.8nm for dry leaf and 6.10nm for fresh leaf. antimicrobial activity was done using different bacterial and fungal species, in antibacterial activity St. aureus show maximum inhibition that is 75% in fresh leaf and 63%in dry leaf while compare to others, S. typhi showed 0% inhibition it was not resistant towards P.niruri. In antifungal activity F.oxysporum has shown maximum inhibition that is 77% for both fresh and dry leaf, penicillium atramentosum showed 0% inhibition it was not resistant towards P.niruri

Experimental Campaign on PEMFC Catalyst Degradation: Enlightening the Impact of Automotive Operational Cycles Combined with Short-Stops

Meeting long-term durability targets is still a significant challenge to achieve a wide-scale commercialization of PEM fuel cells in the transportation sector, for which the cathode catalyst layer is one of the most critical components1. Specifically, high potentials and potential cycling have been identified at the origin of its degradation. Indeed, they are responsible for platinum dissolution under the combined electrochemically oxidizing and acidic environment of catalyst layers. To limit ageing, vehicle systems adopt operating strategies that limit the operating voltage range, as well as they accurately control the start/stop procedures, avoiding both the open circuit voltage (OCV) and frequent air leaks into the anode compartment. In this perspective, passengers vehicles, that introduce frequent switching offs called short-stops2, exploit a procedure based on removing the air at the cathode side whilst supplying hydrogen at the anode.At a laboratory scale, accelerated ageing protocols (AST) are usually utilized for rapidly evaluating the degradation of materials, alternated with periodic performance testing and diagnostics. The conditions that promote Pt nanoparticle degradation have been studied over the past years3,4 mainly starting, and suitably modifying, the protocol proposed by the U.S. Department of Energy (DoE) in hydrogen/nitrogen. In this work, it was instead developed a complimentary approach in order to contribute to the study of the effect of the voltage cycles in a range relevant for the application. Different protocols in hydrogen/air or hydrogen/diluted air atmosphere were applied on a zero gradient cell, emulating the conditions of real operations5. The potential profiles under investigation were restricted to the voltage window accessible in real systems (i.e. ≤ 0.90 V), using commercial Catalyst Coated Membranes (CCM). The role both of the voltage range and of voltage transitions was clarified for a total of 40 tested Membrane Electrode Assembly (MEA) samples. Starting from the reference cycle included in Figure 1A, it was analyzed the influence of: (i) the upper potential limit (UPL); (ii) the lower potential limit (LPL), (iii) the impact of holding times, (iv) the role of short stops, (v) the short stop voltage, (vi) the short stop duration, (vii) scan rates during voltage transitions, (viii) the cathode gas feeding composition, (ix) the relative humidity during the short stop transient. Operando performance information indicates a clear recovery and boosting whenever the voltage was progressively reduced in the range 0.7 V–0 V. The irreversible performance decay recorded through polarization curves and impedance spectra (EIS) appeared dominated by the loss of the electrochemically active surface area (ECSA). The decay of this parameter was strictly connected to the Ostwald ripening mechanism, as corroborated by post mortem images obtained by transmission electron microscopy (TEM), while no Pt precipitation into the ionomer was observed. The average Pt nanoparticle diameter increased from 4.4 nm to 6.5 nm, at which value it almost stabilized. All the voltage profiles studied induced an ageing that was interpreted through the development of a newly formulated semi-empirical ECSA degradation model, which accounts for the role of the different stressors. The available data suggest that the Pt catalyst degradation is a strong function not only of UPL but also of LPL. Quite a large degradation was indeed observed in presence of short stops even in the typical system operational range (i.e. keeping UPL between 0.70 V and 0.90 V, Figures 1 B-D). It is suspected that the Pt nanoparticles are fully reduced at potentials significantly lower than 0.6 V and that their de-passivation enhances their growth. The work proves that attention must be paid on the transitions to low cell voltage (0÷0.4 V) in order to decelerate the catalyst ageing. The results are useful to orientate the selection of the PEMFC operational constraints for reaching the durability targets of the automotive sector (8’000 hours), but they can be also extended for matching the struggling requirements of heavy-duty transportation, namely 25’000 operating hours. This work received support from the Italian government (Progetto PERMANENT - BANDO MITE PNRR Missione 2 Investimento 3.5 A - RSH2A_0O0012). Borup, R. L. et al. Curr. Opin. Electrochem. 21, 192–200 (2020).Takahashi, T. et al. J. Electrochem. Soc. 169, 044523 (2022).Ahluwalia, R. K. et al. J. Electrochem. Soc. 168, 044518 (2021).Kneer, A. et al. J. Electrochem. Soc. 165, 805–812 (2018).Colombo, E. et al. J. Power Sources 553, 232246 (2023). Figure 1

Novel three-dimensional electrode structures with urchin-like pore canal for high-performance microbial fuel cells

In this work, a kind of urchin-like porous structural gel beads as three-dimensional (3D) packed anode materials were prepared to utilize the chemical coprecipitation method, forming the reduced graphene/chitosan/Fe3O4 (rGO/CHI/Fe3O4) gel beads (GFe100). The average diameter of Fe3O4 nanoparticles in the gel beads was about 13 nm, distributing uniformly in GFe100 gel beads in situ. Fe3O4 nanoparticles formed in the material-preparation process had a significant pore-creating function to form urchin-like pore canals with the help of the micro-reactor. The average size of these canals was 13.55 μm, which could enhance more functional microbes in the gel beads to strengthen the biocompatibility and extracellular electron transfer (EET) of anode electrodes. The maximum output voltage and power density of GFe100 was 759 mV and 17.823 W·m-3, which was 2.3 times (327 mV) and 23.21 times (0.768 W m-3) higher than that of GFe0 prepared without any addition of Fe2+, respectively. The significant electricity generation performance of GFe100 was mainly attributed to the urchin-like canal structure. Exoelectrogens possessed the macropore structure for the controlled diffusion process and extracellular metabolic products occupied the micropore and mesopore structure donating for the surface reactant process. This work suggested that three-dimensional gel beads filled into the anode chamber might be the potential for long-term MFC practice application with a high electricity generation performance.

Photochemical Synthesis of Noble Metal Nanoparticles: Influence of Metal Salt Concentration on Size and Distribution.

This paper explores the photochemical synthesis of noble metal nanoparticles, specifically gold (Au) and silver (Ag) nanoparticles, using a one-component photoinitiator system. The synthesis process involves visible light irradiation at a wavelength of 419 nm and an intensity of 250 mW/cm2. The radical-generating capabilities of the photoinitiators were evaluated using electron spin resonance (ESR) spectroscopy. The main objective of this study was to investigate how the concentration of metal salts influences the size and distribution of the nanoparticles. Proposed mechanisms for the photochemical formation of nanoparticles through photoinitiated radicals were validated using cyclic voltammetry. The results showed that the concentration of AgNO3 significantly impacted the size of silver nanoparticles, with diameters ranging from 1 to 5 nm at 1 wt% and 3 wt% concentrations, while increasing the concentration to 5 wt% led to an increase in the diameter of silver nanoparticles to 16 nm. When HAuCl4 was used instead of AgNO3, it was found that the average diameters of gold nanoparticles synthesized using both photoinitiators at different concentrations ranged between 1 and 4 nm. The findings suggest that variations in HAuCl4 concentration have minimal impact on the size of gold nanoparticles. The photoproduction of AuNPs was shown to be thermodynamically favorable, with the reduction of HAuCl4 to Au0 having ∆G values of approximately -3.51 and -2.96 eV for photoinitiators A and B, respectively. Furthermore, the photoreduction of Ag+1 to Ag0 was demonstrated to be thermodynamically feasible, with ∆G values of approximately -3.459 and -2.91 eV for photoinitiators A and B, respectively, confirming the effectiveness of the new photoinitiators on the production of nanoparticles. The synthesis of nanoparticles was monitored using UV-vis absorption spectroscopy, and their sizes were determined through particle size analysis of transmission electron microscopy (TEM) images.

Bismuth-Antimony Alloy Nanoparticles Embedded in 3D Hierarchical Porous Carbon Skeleton Film for Superior Sodium Storage.

A composite film that features bismuth-antimony alloy nanoparticles uniformly embedded in a 3D hierarchical porous carbon skeleton is synthesized by the polyacrylonitrile-spreading method. The dissolved polystyrene is used as a soft template. The average diameter of the bismuth-antimony alloy nanoparticles is ~34.5 nm. The content of the Bi-Sb alloy has an impact on the electrochemical performance of the composite film. When the content of the bismuth-antimony alloy is 45.27%, the reversible capacity and cycling stability of the composite film are the best. Importantly, the composite film outperforms the bismuth-antimony alloy nanoparticles embedded in dense carbon film and the cube carbon nanobox in terms of specific capacity, cycling stability, and rate capability. The composite film can provide a discharge capacity of 322 mAh g-1 after 500 cycles at 0.5 A g-1, 292 mAh g-1 after 500 cycles at 1 A g-1, and 185 mAh g-1 after 2000 cycles at 10 A g-1. The carbon film prepared by the spreading method presents a unique integrated composite structure that significantly improves the structural stability and electronic conductivity of Bi-Sb alloy nanoparticles. The 3D hierarchical porous carbon skeleton structure further enhances electrolyte accessibility, promotes Na+ transport, increases reaction kinetics, and buffers internal stress.

Transcriptome analysis of some genes of Staphylococcus aureus exposed to alkylated, nano- and native chitosans

Chitosan, including native, N- alkyl (AlkCs), and nanoparticles chitosan (CsNPs), were prepared and characterized. Average size and hydrodynamic diameter of nanoparticles were determined at 126 nm and 240 nm with a polydispersity index (PDI) of 0.154 and zeta potential of 30 mV, respectively. Crystallinity index for Cs, AlkCs, and CsNPs was calculated as 57.85, 30.24, and 24.85, respectively. Minimum concentration of growth inhibition (125.78 µg/ml) and lethality (100 µg/ml) was observed for CsNPs (P < 0.05). CsNPs and AlkCs showed the highest diameter of the growth inhibition zone at 1250 μg/mL concentration, respectively (P < 0.05). Membrane permeability test, the highest absorption of ortho-nitrophenol was observed after 90 min with 0.11 nm. The most significant decrease in absorption in chitosan was observed at the end of 120 min. DAPI (4′,6-Diamidino-2-Phenylindole) staining test showed higher cell death of bacteria treated with AlkCs and CsNPs. Images obtained from atomic force microscopy (AFM) showed a change in the morphology of the treated cells compared to the spherical and clustered control cells. A significant increase in the expression of vraS, vraR, lytM, lrgA and lrgB genes was observed as a result of induction of S. aureus cell wall by Cs, AlkCs and CsNPs, d.

Synthesis of carbon-encapsulated copper nanoparticles by the electrical explosion of wire method

The synthesis of carbon-encapsulated copper nanoparticles (Cu&C NPs) by the high-productive method of the electrical explosion of wire (EEW) is presented. Copper wire was evaporated by high-energy electrical current pulses. Evaporation of Cu and the consequent condensation of spherical nanoparticles took place in argon with the controlled addition of butane, which provided encapsulation of copper nanoparticles in carbon shells. Carbon was deposited in the form of several graphite layers, which completely covered the surface. The encapsulation diminished the agglomeration of carbon-encapsulated copper nanoparticles (Cu@C NPs) during their condensation and substantially diminished their average diameter. Upon the deposition of about 4 % of carbon, the average diameter of nanoparticles decreased more than three-fold – from 130 to about 40 nm. Simultaneously, the specific surface area of Cu@C NPs increased from 7 to 35 m2/g. The deposited dense and gas tight carbon shells protected the surface of particles from oxidation. It prevented the self-ignition of as-synthesized nanoparticles at the exposure to ambient air and provided stability to oxidation during long-term storage as well.

Development of lipid nanoparticles with nystatin for an antifungal action

Fungal diseases currently affect about a quarter of the population worldwide. Fungi infections caused by Candida albicans have been described as a significant concern to public health. The spectrum of clinical diseases caused by this fungi species range between vulvovaginal candidiasis, oral candidiasis, candidemia and mucositis. The emergence of resistance mechanisms towards antifungal therapy greatly hampers successful management of illness and patient outcome. Nystatin, an antifungal drug, is categorized as a class IV of Biopharmaceutical Classification System, presenting low aqueous solubility and low intestinal permeability. Nowadays, the emerging platform of nanotechnology and lipid nanoparticles, notably solid lipid nanoparticles (SLN), has been subject to growing attention over recent past, owing to the promising properties of vectorization among a substantial variety of pharmaceutical drugs. Due to its hydrophobic proprieties, nystatin was encapsulated in SLN. Thus aiming to understand the relationship between the use of nanosystems and the improvement of the therapeutic effect. The aim of this work was to formulate SLN with nystatin by different methods (high speed homogenization and ultrasonication) with optimization of several parameters and formulation of 2 gels (one of them containing nanoparticles).&#x0D; Initially, 3 lipids were used: Compritol® 888 ATO, cetyl palmitate and Precirol® ATO 5 and, after the study of several parameters (size, encapsulation efficiency (EE) and polymorphic behaviour of the lipids), Precirol® ATO 5 was chosen as the lipid with the most satisfactory results. The results of the present work showed that the assay method of nystatin was linear, specific and presented repeatability. The average diameter of empty nanoparticles (NPs) and with drug (Precirol-NYS NPs) was, respectively, 306 nm and 260 nm and an EE of 67.8%. Regarding stability, SLN with drug proved to be more stable than SLN without drug. The polymer used for formulation of gels was the polymer commonly known by the trade name Carbopol® 940. The yield of 0.5% Carbopol® gel preparations and 0.5% Carbopol® gel + 10% Precirol-NYS NPs were 87.2% and 91.39%, respectively.

Green Synthesis of ZNO Nanoparticles using Aloe Vera Leaves Extract

Characterization of the created ZnO nanoparticles using the following techniques: Fouriesr Transform Infra RedSpectrum (FTIR), Scanning Electron Microscopic (SEM), Atomic Force Microscope (AFM). Atomic Force Microscopy (AFM) was employed to describe the surface morphology, particle size in nanoscale, dimeter and roughness of the surface for zinc nanoparticles prepared from plant extraction. The morphology images of pure plant extract and biosynthesised zinc nanoparticles that explains the 3D image of the surface morphology.The particle size in nanoscale of pure plant extraction was 87.22nm and zinc nanoparticles were found to have a particle size of 36.42nm. height cumulation distributions that determine the volume percentage of plant extract's grain size particles and biosynthesised zinc nanoparticles, recording 50.269 nm average hight of plant extraction and 21.515 nm average height of synthesized zinc nanoparticles, displays the Granularity Cumulation Distribution, which calculates the volume percentage of the diameter of plant extract and synthetic zinc nanoparticles. The average diameter of plant extract was 133.77 nm, whereas the average diameter of synthetic zinc nanoparticles made by plants extract was 52.84 nm. The roughness of the surface RMS (Root mean square) of pure plant extraction and the synthesized zinc nanoparticles that that RMS of plant extract was 13.2nm, while the RMS of synthesized zinc nanoparticles was 5.21nm. Scanning electron microscope (SEM) analysis explained the morphology of the surface and shape formation of plant extract and synthesized zinc nanoparticles , that exhibits the micrograph of plant extraction and synthesized zinc nanoparticles and shows that the zinc nanoparticles were formed as nanosheets and hierarchical shape in huge quantities and different lengths nanosheets. Scanning electron microscopy (SEM) element mapping at the microstructural level shows the distribution and quantities of zinc nanoparticles elements prepared from the plant extract and oxygen.It is noticed that the high amount of zinc prepared. FTIR findings for the crude The appearance of a broad peak at (2320.47 cm-1) in an Aleo vera extract is due to the stretching O-H groups of phenolic groups and carbohydrate monomers.

Silver-Nanoparticle-Decorated Fused Carbon Sphere Composite as a Catalyst for Hydrogen Generation

The dwindling supply of fossil fuels has resulted in a search for an efficient alternative energy source. Hydrogen gas offers an abundant, clean-burning supply of energy that can be readily produced over time via the water-splitting reaction of sodium borohydride (NaBH4). This study explored the synthesis of a novel catalyst comprised of silver nanoparticles supported on fused carbon spheres (AgNP-FCS). This composite catalyst was then tested for its ability to optimize the hydrolysis reaction of NaBH4. The fused carbon spheres (FCS) were synthesized via a sustainable source, namely a dextrose solution. The synthesized AgNP-FCS catalyst was characterized using transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The average diameter of silver nanoparticles on the catalyst was found to be 30 nm with 3.7% loading. This catalyst was tested under various reaction conditions, including temperatures, doses of NaBH4, and solution pHs. The activation energy of the reaction as catalyzed by AgNP-FCS was determined to be 37.0 kJ mol−1, which was competitive when compared to similar catalysts for this reaction. A study of the reusability of this catalyst suggests that the catalyst can be used multiple times consecutively with no loss in hydrogen generated. This material presents an opportunity for a sustainable catalyst to optimize the amount of hydrogen generated via the hydrolysis of NaBH4.

Synthesis and characterization of magnesium oxide nanoparticles by atmospheric non-thermal plasma jet

The invention of the system which facilitates and assures the use of atmospheric-pressure plasma technology has been used in several fields, including medicine and nanotechnology. In our work, magnesium oxide (MgO) nanoparticles (NPs) were created using a high voltage power supply of 21 ​kV at high-frequency equipment that produced a 6 ​kHz output. MgO NPs were successfully created at various times. X-Ray Diffraction (XRD) analysis showed that MgO NPs have a polycrystalline and an average crystalline size of 9.365 and 14.253 ​nm in both preparation times (10 and 12 ​min). Additionally, field emission scanning electron (FE-SEM) images show the single nanoparticles appear flake-like, with a thickness of 10 ​nm at 500 ​nm magnification and a width of 20 ​nm. Transmission Electron Microscopy (TEM) was employed to analyze the homogeneous, compact, and dense surface of the produced MgO NPs. Transmission electron microscopy (TEM) analysis showed that the MgO nanoparticle's average diameter ranged from 6 to 18 ​nm. Atomic Force Microscopy (AFM) was also used to uncover the degree of cooperation between the surfaces of MgO NPs, and the results showed a high extraordinary topographic contrast of the MgO NPs with a surface roughness of 2.170 ​nm.

A Comparative Study of the Biodurability and Persistence of Gold, Silver and Titanium Dioxide Nanoparticles Using the Continuous Flow through System.

The potential for nanoparticles to cause harm to human health and the environment is correlated with their biodurability in the human body and persistence in the environment. Dissolution testing serves to predict biodurability and nanoparticle environmental persistence. In this study, dissolution testing using the continuous flow through system was used to investigate the biodurability and persistence of gold nanoparticles (AuNPs), silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2 NPs) in five different simulated biological fluids and two synthetic environmental media to predict their behaviour in real life situations. This study examined the physicochemical properties and agglomeration state of gold, silver and titanium dioxide nanoparticles before and after dissolution tests using three different techniques (UV-vis, XRD and TEM). The UV-vis spectra revealed that all three nanoparticles shifted to higher wavelengths after being exposed to simulated fluids. The titanium powder was found to be mixed with both rutile and anatase, according to XRD examination. The average diameter of gold nanoparticles was 14 nm, silver nanoparticles were 10 nm and titanium dioxide nanoparticles were 25 nm, according to TEM images. The gold and silver nanoparticles were observed to be spherical, but the titanium dioxide nanoparticles were irregular in shape, with some being spherical. The level of dissolved nanoparticles in simulated acidic media was higher in magnitude compared to that dissolved in simulated alkaline media. The results obtained via the continuous flow through dissolution system also displayed very significant dissolution rates. For TiO2 NPs the calculated half-times were in the range of 13-14 days, followed by AuNPs ranging between 4-12 days, significantly longer if compared to the half-times of AgNPs ranging between 2-7 days. AuNPs and TiO2 NPs were characterized by low dissolution rates therefore are expected to be (bio)durable in physiological surroundings and persistent in the environment thus, they might impose long-term effects on humans and the environment. In contrast, AgNPs have high dissolution rates and not (bio)durable and hence may cause short-term effects. The results suggest a hierarchy of biodurability and persistence of TiO2 NPs > AuNPs > AgNPs. It is recommended that nanoparticle product developers should follow the test guidelines stipulated by the OECD to ensure product safety for use before it is taken to the market.

Synthesis of Chitosan-Silver Nanocomposite and Its Evaluation as an Antibacterial Coating for Mobile Phone Glass Protectors.

An easy and environment-friendly route for antibacterial coating suited for mobile phone glass protectors was successfully demonstrated. In this route, freshly prepared chitosan solution in 1% v/v acetic acid was added with 0.1 M silver nitrate solution and 0.1 M sodium hydroxide solution and incubated with agitation at 70 °C to form chitosan-silver nanoparticles (ChAgNPs). Varied concentrations of chitosan solution (i.e., 0.1, 0.2, 0.4, 0.6, and 0.8% w/v) were used to investigate its particle size, size distribution, and later on, its antibacterial activity. Transmission electron microscope (TEM) imaging revealed that the smallest average diameter of silver nanoparticles (AgNPs) was 13.04 nm from 0.8% w/v chitosan solution. Further characterizations of the optimal nanocomposite formulation using UV-vis spectroscopy and Fourier transfer infrared spectroscopy were also performed. Using a dynamic light scattering zetasizer, the average ζ-potential of the optimal ChAgNP formulation was at +56.07 mV, showing high aggregative stability and an average ChAgNP size of 182.37 nm. The ChAgNP nanocoating on glass protectors shows antibacterial activity against Escherichia coli (E. coli) at 24 and 48 h of contact. However, the antibacterial activity decreased from 49.80% (24 h) to 32.60% (48 h).