Ag Peak Research Articles

The Evaluation and Detection of the Chemical Bond Between Silane Coupling Agent and Silver Layer on Alkali Activated Fly Ash

In this study, wettability was employed to evaluate the effect of alkali activation by NaOH on different fly ash (FA) particle sizes. The results indicated that the surface wettability of FA particles with 13.8 μm increased from 0.025 g2/s to 0.034 g2/s after activation by the NaOH solution, which is suitable for silane modification and electroless plating. X-ray photoelectron spectroscopy (XPS) was used to analyze whether three kinds of silane coupling agents coated on FA surfaces could detect the chemical bonds between silane coupling agents coated on the FA surface and silver layers by shortening the plating time. The XPS results demonstrated that N-Ag coordination bonds can be detected by reducing silver plating time to 2 min for Ag-plated FA modified by N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (KH792). However, there were no chemical bonds detected for Ag-plated FA modified by γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) and methyltrimethoxysilane (MTMS), even when the satellite peak of Ag disappeared after plating for 80 s. The SEM showed that Ag particles agglomerated on FA surfaces, and even a bare surface was found after modification by KH560 and MTMS, which further proved no chemical bonds between silver layers and the silane coupling agents.

Antiproliferative Activity of Green Process Synthesized Epipremnum Aureum Silver Nanoparticles Against Breast Cancer Mcf-7 Cells

Breast cancer (BC) is one of the most severe cancers among women globally. Local recurrence of cancer after surgery is usually seen as a poor predictor of prognosis. Cancer treatment has been significantly transformed by the progress made in nanotechnology, and nanoparticles have emerged as pivotal components in this domain. Metal nanoparticles are produced using plant extract in green synthesis or eco-friendly techniques for the stabilizing and reducing substance. The current research study synthesizes silver nanoparticles (AgNPs) from Epipremnum aureum leaf extract using the green synthesis method and its evaluations using UV-Vis, FTIR, XRD, SEM, and EDX characterization techniques. The EA-AgNPs exhibit a significant absorption peak at wavelength 420 nm, which confirms the AgNP's presence by UV-visible spectrometer. FTIR spectrum reveals the strong band at 1586.020 cm-1 confirming the O-H group presence. The stretching and bending modes of vibration of the NO32- a sharp band represented molecule at 1382.987 cm-1 and a very tiny band at 1272.241, 1077.355 cm-1. The XRD spectrum exclusively showed Ag peaks, with no additional chemical contaminants, signifying the sample's purity, and the average particle size was 12.92 nm. MTT assay result observed high cytotoxic activity of EA-AgNPs against MCF-7 cells with IC50= 0.1106 µg/ml. This research study aims to preliminary investigate the in-vitro antiproliferative activity of green process synthesized Epipremnum Aureum silver nanoparticles (EA-AgNPs) against breast cancer cell line (MCF-7).

Enhancement of antimicrobial properties and cytocompatibility through silver and magnesium doping strategies on copper oxide nanocomposites

In the present study, silver (Ag), magnesium (Mg), and the various molar ratios of Ag:Mg-doped copper oxide nanocomposites (CuO NCs) were synthesized by the co-precipitation method. The CuO NC samples calcined at 500 °C were further analyzed for their morphological, structural, functional, and optical properties. Adding single and dual doping increased the pristine CuO band gap from 1.28 to 1.50 eV. The Ag and Mg metal peaks were revealed in the Fourier transform infrared (FTIR) analysis, while an elevated Mg band was observed in all Mg-doped samples in the Raman results. All CuO NCs showed a monoclinic crystalline structure, flake, and rod-like morphologies. Microbes of Bacillus subtilis, Shigella dysenteriae, and Candida albicans were tested against different concentrations of CuO NCs. Better results for all tested microbes were observed with the 2 mg concentration. The high cytotoxicity effect was observed in the pristine and Cu:Ag (94:6) sample, and other CuO NCs, which demonstrated over 80 % viability in RAW 246.7 cells at a concentration of 0.5 µg/ml. Remarkably, over 94 % cell viability at 0.5 µg/ml was achieved with the Cu:Ag:Mg (94:3:3) NCs ratio, owing to the synergistic effect of the ion-releasing ability of Cu2+, Ag2+, and Mg2+ ions. It possesses a distinctive high aspect ratio shape, is ion-releasing, and has excellent cytocompatibility. The suitability of the Cu:Ag:Mg (94:3:3) NCs ratio for addressing microbial challenges in healthcare is suggested by their distinct characteristics, indicating the promising potential for future biomedical applications.

The encapsulation of noble metal over metal oxide semiconductor TiO2@Ag for the degradation of sulphur dye in effluent water by photocatalysis and electrochemical water splitting

Metal Oxide Semiconductor - Metal core-shell nanostructure with TiO2 as core and Ag nanoparticles as shell (TiO2@Ag) have been synthesized by a simple, environmentally friendly room temperature wet chemical method. The prepared TiO2@Ag core-shell nanoparticle was characterized by using various analytic techniques. X-ray diffraction analysis confirms the formation of tetragonal bcc structure anatase phase of TiO2 and Face-Centred Cubic structure (fcc) of silver in core-shell nanostructure. Fourier Transform Infrared Spectroscopy (FTIR) study proved the presence of characteristic peaks of both TiO2 and Ag. XPS study revealed the existence Ti4+ and metallic silver in core-shell nanostructure, High - Resolution Transmission Electron Microscopy (HR–TEM) and High - Resolution Scanning Electron Microscopy (HR–SEM) revealed the covering of Ag nanoparticles at the surface of TiO2 spheres. The TiO2@Ag core-shell nanoparticles exhibit a high residual mass of 95.9 % and stability to withstand up to 1000 °C. The prepared TiO2@Ag core-shell nanoparticles as photocatalyst showed enhanced photocatalytic degradation (240 min) of sulphur dye in effluent water with a degradation efficiency of 81 % and capable of employing in wastewater treatment to eliminate toxic elements present in it. In the current study, we have used core-shell nanoparticles prepared using the wet chemical method at room temperature. The prepared core-shell nanoparticles were used to study the photocatalytic degradation of sulphur black dye directly collected from textile effluent water. They were also used for the production of oxygen and hydrogen through the electrolysis process. The synthesized TiO2@Ag core-shell nanoparticles act as effective electrocatalyst for the production of oxygen and hydrogen through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) using the electrolysis process.

Advances in LDI-MS Analysis: The Role of Chemical Vapor Deposition-Synthesized Silver Nanoparticles in Enhancing Detection of Low-Molecular-Weight Biomolecules.

In this investigation, we detail the synthesis of silver nanoparticles (AgNPs) via a precise chemical vacuum deposition (CVD) methodology, aimed at augmenting the analytical performance of laser desorption/ionization mass spectrometry (LDI-MS) for the detection of low-molecular-weight analytes. Employing a precursor supply rate of 0.0014 mg/s facilitated the formation of uniformly dispersed AgNPs, characterized by SEM and AFM to have an average diameter of 33.5 ± 1.5 nm and a surface roughness (Ra) of 11.8 nm, indicative of their homogeneous coverage and spherical morphology. XPS and SEM-EDX analyses confirmed the metallic silver composition of the nanoparticles with Ag peak splitting, reflecting the successful synthesis of metallic Ag. Comparative analytical evaluation with traditional MALDI matrices revealed that AgNPs significantly reduce signal suppression, thereby enhancing the sensitivity and specificity of LDI-MS for low-molecular-weight compounds such as triglycerides, saccharides, amino acids, and carboxylic acids. Notably, the application of AgNPs demonstrated a superior linear response for triglyceride signals with regression coefficients surpassing 0.99, markedly outperforming conventional matrices. The study further extends into quantitative analysis through nanoparticle-based laser desorption/ionization (NALDI), where AgNPs exhibited enhanced ionization efficiency, characterized by substantially lower limits of detection (LOD) and quantification (LOQ) for tested standards. Particular attention was paid to lipids with a detailed examination of their fragmentation pathways. These results highlight the significant potential of AgNPs synthesized via CVD to transform the analytical detection and quantification of low-molecular-weight compounds using NALDI. This approach offers a promising avenue for expanding the scope of analytical applications in mass spectrometry and introducing innovative methodologies for enhanced precision and sensitivity.

Photo-catalytic dye degradation potentials of Ag-Pd bimetallic nanoparticles synthesized from Vitex negundo.

Plant extracts are a great alternative to synthesizing nanoparticles of different metals and metal oxides. This green synthesis method has opened up numerous possibilities in various scientific domains. In present study, Leaf extract from Vitex negundo is a non-deciduous, long-lasting shrub from the Verbenaceae family is used as capping and reducing agents for the synthesis of silver and palladium nanoparticles. The characterization study UV-vis spectrophotometer analysis showed absorbance value around 320nm which confirming that Ag-Pd nanoparticles have been successfully obtained. Further, SEM is used to investigate the morphology of Ag-Pd NPs, which revealing their spherical and rod-like configuration, aggregation, and the size of the particles are obtained between 50 and 100nm. The successful synthesis of Ag-Pd NPs was further confirmed by the EDAX chart, which displayed the peak of Ag and Pd at bending energies between 0.5 and 1.5keV. According to the quantitative study, Ag and Pd ions found about 5.24 and 13.28%, respectively. In addition, surface studies with TEM confirming that synthesized Ag-Pd NPs are predominates with spheres structure morphologies, with sizes averaging 11.20nm and ranging from 10 to 20nm. Further, Ag-Pd nanoparticles was applied as potential photocatalyst materials to degrade methylene blue dye and found about 85% of the degradation efficiency within 150min of the sunlight exposure thus could be used as catalyst to removal of hazardous organic dye molecules.

Enhancing Radiosensitization of Non-Small Cell Lung Cancer with Graphene Oxide@AgPt Nanocomposites: A Bioinformatics Study

In this study, we employed bioinformatics techniques to investigate the radiosensitization mechanisms of graphene oxide (GO) and silver-platinum (AgPt) nanocomposites (NCs) on microRNAs (miRNAs) in non-small cell lung cancer (NSCLC). The GO@AgPt nanocomposites were synthesized through a hydrothermal method involving graphene oxide. Characterization and structural analysis were performed using transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Our experimental model was A549 cells, categorized into three groups: the blank group, control group, and GO@AgPt group. The blank group remained untreated, while the control group was exposed to 4Gy X-ray irradiation. The GO@AgPt group received 15 μg/mL GO@AgPt for 4 hours before exposure to 4Gy X-ray irradiation. Cellular RNA was extracted from each group, and a transcriptome sequencing library was constructed. Subsequent analysis identified differential genes, followed by gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway assessments. Our results revealed the uniform attachment of AgPt spherical nanoparticles (NPs) with an approximate diameter of 10 nm to the GO surface. The GO@AgPt nanocomposites comprised four single-layer GO sheets, each approximately 4 nm in thickness, with the Ag peak area being about six times that of the Pt peak area. A total of 197 miRNAs exhibited differential expression between the GO@AgPt and control groups, with 94 up-regulated and 103 down-regulatedmiRNAs. These miRNAs were associated with biological processes such as positive regulation of gene expression, cell surface interactions, and growth factor binding. Furthermore, they were implicated in various pathways, including microRNAs in cancer, fatty acid metabolism, human T-cell leukemia virus 1 infection, FoxO signaling, and alcoholic liver disease. Our findings demonstrate that GO@AgPt nanocomposites enhance the radio-sensitization effect in NSCLC, with 197 differentialmiRNAs participating in the process.

Environmental friendly approach on biosorption of Ag nanoparticles using Aspergillus terreus BIOS PTK 6 biomass: Optimization, kinetics and characterization studies

The present study focused on the biosorption of Aspergillus terreus dead biomass for the removal of silver nanoparticles (AgNPs) from aqueous solution. For the better removal of AgNPs, pH, temperature, incubation time, initial biomass concentration and agitation speed were optimized and AgNPs treated as well as control biosorbents were characterized using Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX) analyses. In our study, the optimum conditions of pH, temperature, incubation time, initial biomass concentration and agitation speed for the maximum removal of AgNPs was found to be 4, 30 °C, 200 min, 1 mg/mL and 125 rpm, respectively. Interestingly, in our study, Langmuir isotherm model was best correlated with the highest regression coefficient (R2) of 0.992 and the maximum biosorption was found to be 740.63 μg/mL. FTIR results showed that carboxyl, carbonyl and secondary amine groups were involved in the biosorption of AgNPs. FESEM images of AgNPs treated biosorbent depicted rough surface and the presence of AgNPs on the surface of biosorbent was clearly observed. EDX spectrum showed Ag peak, which confirmed the successful uptake of AgNPs by A. terreus dead biomass. Thus, our study shows that A. terreus could be used as a cost-effective eco-friendly biosorbent for AgNPs removal from aqueous solution. Therefore, exploiting the same fungus for both synthesis and removal of AgNPs could be a novel approach in the context of mycoremediation practices.

Effect of Ag-doping process into the yttrium iron garnet (Y3Fe5O12) thin films on the structural, magnetic and optical properties

In this work, the effect of Ag doping process (directly and as a nanoparticle) into the Y3Fe5O12 (YIG) thin films on the structural, morphological, optical and magnetic properties was studied in detail. Ag-doped YIG thin films were grown on thermally oxidized Si substrates by following sol–gel and spin-coating methods. All films were crystallized without cracks by two-stages heat treatment process. The XRD patterns confirm the formation of YIG peaks, and metallic Ag peaks which settled into the structure without bonding with the YIG components. In both Ag doping processes, the coercive field (Hc) and saturation magnetization (Ms) values of the samples containing 3% Ag are significantly lower than the other samples. The Ms values of 5% Ag doped samples were found the highest in both series. The Ms values of the films between in-plane and out-of-plane measurement increased with the Ag concentration. The optical measurements indicate an absorption peak in the range of 0–4 eV in both sample series and the optical band gap of the films decreased with the Ag doping due to its metallic characteristic. The ferromagnetic resonance measurements indicate that the lowest FMR linewidth as 92 Oe is seen in the 1% Ag-doped YIG sample. The relatively cheap and easy production of the used method and additive material may enable the widespread the usage of Ag-doped YIG thin films in magneto-optical devices.

Designing bi-functional Ag-CoGd0.025Er0.05Fe1.925O4 nanoarchitecture via green method

In the current study, we developed a simple and biocompatible method for producing core–shell nanoparticles (NPs). Citrate auto combustion and green procedures were used to create core–shell Ag/CoGd0.025Er0.05Fe1.925O4 (Ag/CGEFO) sample with an average crystallite size of 26.84 nm. The prepared samples were characterized via different structural techniques, such as x-ray diffraction (XRD), Raman Spectroscopy (RS), High-Resolution Transmission Electron Microscopy, and Energy Dispersive x-ray analysis. These analyses were utilized to characterize and confirm the successful formation of the core–shell architecture. For core–shell NPs, all peaks of Ag and CGEFO ferrite are detected in the XRD, confirming the co-presence of the ferrite spinel phase and the cubic Ag phase. The magnetic hysteresis curves demonstrate typical hard ferri-magnetic behavior along with maximum magnetic saturation values up to 53.74 emu g−1 for the CGEFO sample, while an enhanced coercivity is detected for the coated sample. Moreover, the width of the hysteresis loop is increased for the Ag/CGEFO sample compared to the uncoated one. This indicates that the addition of Ag as a shell increases magneto crystalline anisotropy. Moreover, the E g of uncoated CGEFO is equal to 1.4 eV, increasing to 3.6 eV for coated ones. This implies the influence of CGEFO is diminished when the surface is coated with Ag (shell), and the reflectance of the Ag/CGEFO core–shell is nearly dependent on the reflectance of the Ag shell layer. Consequently, the Ag/CGEFO can be used as a light shielding substance.

Superior visible-light absorbing Ag@ZnO nanorods hybrid photocatalyst for efficient decomposition of commercial pharmaceuticals tetracycline and amoxicillin

This work assesses the role of the noble metal silver in the visible-light sensitization of UV-active ZnO by introducing a localized plasmonic resonance effect and enhancing the spatial charge carrier separation. We herein synthesize ZnO nanorods via a solvothermal approach, yielding nanorods of length and diameter 1.356 ± 0.619 μm and 120.56 ± 25.09 nm, respectively. Silver nanoparticles are reduced on the surface of ZnO nanorods via the photodeposition route. XRD spectra reveal a high crystallinity and wurtzite-type structure for ZnO with new peaks for cubic phase Ag upon Ag-loading. The diffraction peaks shift upon Ag modification, indicating partial incorporation of Ag into the ZnO lattice. Further, upon Ag-decoration, a slight increase in dislocation density and micro strain is obtained, which could suppress the recombination rate of charge carriers. The DRS spectra reveal a band gap contraction of materials from 3.19 to 2.98 eV with increasing Ag density. The PL spectra confirmed that the optimum Ag concentration of 3 wt% is proficient in harvesting visible light towards high photocatalytic degradation efficiencies of tetracycline (92.1 %) and amoxicillin (76.4 %) in 90 min as compared to 49.4 % and 38 % over pristine ZnO nanorods. TOC studies reveal only partial mineralization of ∼42.7 % (tetracycline) and ∼31.3 % (amoxicillin) due to the formation of reaction intermediates identified by HR-MS chromatograms. In addition, degradation pathways are proposed through the fragments at different m/z ratios.

Synthesis of Au@Ag core-shell nanocubes with finely tuned shell thicknesses for surface-enhanced Raman spectroscopic detection.

In this work, we describe a facile method for generating monodisperse Au@Ag core-shell nanocubes with well-controlled size and fine-tuned Ag shell thicknesses. In this synthesis method, Au nanocubes were prepared via the seed-mediated growth method. Then, Au@Ag nanocubes with the core-shell structure were prepared separately by reducing AgNO3 with AA using as-prepared Au nanocubes as seeds. The thickness of Ag shells could be finely tuned from 3.6 nm to 10.0 nm by varying the concentration of the AgNO3 precursor. By investigating the localized surface plasmon resonance (LSPR) properties of Au@Ag nanocubes in relation to the thickness of the Ag shell, we found that the intensity of the characteristic peak of Ag gradually increases and that of Au gradually decreases as the thickness of the Ag shell increases. Additionally, surface-enhanced Raman scattering (SERS) properties of Au@Ag core-shell nanocubes were evaluated using rhodamine 6G (R6G) as the probe molecule. Interestingly, Au@Ag nanocubes exhibit efficient SERS intensities compared to the Au nanocubes, and Ag shell with a thickness of about 8.4 nm exhibits the optimal SERS activity. In addition, our results also demonstrated that Au@Ag nanocubes with an Ag shell thickness of 8.4 nm exhibited high SERS sensitivity and are capable of probing the analyte down to 10-12 M. The results obtained here suggest that Au@Ag core-shell nanocubes might serve as a nanoprobe for SERS-based analytical and biosensing applications.

Green synthesis of size-controlled silver nan particles and their anti-cancer potentiality

Silver nanoparticles (Ag-NPs) are now well recognized as one of the most prevalent kinds of materials that are put to use in a wide variety of biomedical applications, most notably as an anti-cancer agent. In the current investigation, Ag-NPs were effectively produced by reducing silver ions by employing the leaf extract of Artocarpus heterophyllus as a source of reducing and capping agents. By altering the quantity of the silver nitrate solution, we successfully synthesized three distinct kinds of Ag-nanoparticles that were mediated by Artocarpus heterophyllus leaf extract. The X-ray diffraction (XRD) analysis first confirmed the formation of metallic silver, where peaks were found at fixed angles. XRD method was also used to validate the crystal geometry of the Ag-NPs, revealing that the Ag-NPs had a face-cantered cubic structure. The calculated average crystallite sizes of Sample-1 Ag-NPs, Sample-2 Ag-NPs, and Sample-3 Ag-NPs were 20.34 nm, 16.99 nm, and 18.88 nm, respectively. Ag-NPs were also confirmed from EDX analysis and firm Ag peaks, including several organic compound peaks. The nanoparticle’s range was between 120 nm and 220 nm, and the average particle size was near 170 nm, as found in the SEM image, and accumulation was observed in the SEM image. Using Fourier Transform Infrared (FT-IR) spectroscopy, we determined the functional groups of organic compounds that might be responsible for reducing agents and the presence of capping agents on the surface of Ag-NPs. The cell viability test was used to assess the cytotoxicity using the HeLa cell, a human carcinoma cell. The results revealed that the produced Ag-NPs demonstrated toxicity against carcinoma cells.

Synthesis and Characterization of Amorphous Selenium, Cadmium and Silver Selenide Thin Films on Polyamide-6

Increasing photon absorption by capturing light is an important way to increase the efficiency of photovoltaic devices. In this regard, the small optical band gap (Eg) and high absorption coefficient of Se-containing thin nanofilms make them ideal for next generation photovoltaic devices based on selenides. Amorphous selenium was introduced into polyamide-6 (PA 6) via a chemical synthesis in a bath and the influence of the products of its reaction with Cd2+ and Ag+ ions on the film phase composition, topographic and optical properties were evaluated. AFM data have revealed that the surface roughness of the a-Se/PA 6 composite noticeably increases compared to that of unreacted PA 6. However, at later stages of film deposition, the roughness decreases, and the thin film becomes smoother and uniform. The incorporation of solid inorganic nanoparticles into flexible polyamide network causes chain stretching, which has been confirmed by ATR-FTIR spectroscopy data. The data of X-ray diffraction analysis, depending on the stage of synthesis, showed the crystalline composition of the film with peaks of Se8, CdSe, Ag2Se and Ag, which may explain the observed optical properties. The optical properties of the composites indicate a shift in the band gap from 4.46 eV for PA 6 to 2.23–1.64 eV upon the stepwise deposition of amorphous Se, CdSe and Ag2Se. Eg is conveniently located in the visible region of solar energy, making the obtained nanofilms ideal for solar energy harvesting.

Microstructure, creep properties, and electrical resistivity of magnetron sputtering deposited SAC305 thin films

This paper investigates the surface morphology, mechanical properties, and electrical resistivity of 96.5Sn–3.0Ag–0.5Cu (SAC305) thin films deposited on Si and SiO2 substrates through RF magnetron sputtering. Various deposition parameters were tested using both DC and RF power sources at different pressures and powers to produce robust continuous films. The most optimal surface morphology, with an average grain size of ∼1 μm and a thickness of ∼2.2 μm, was accomplished at a pressure of 2.4 mTorr and 200 W power. After polishing, a uniform thickness of 1800 nm with a mean roughness (Ra) of 14.9 nm was obtained. The samples contained polycrystalline β-Sn grains at (200) diffraction planes with a preferred orientation 2θ of 30.70°. Although the XRD pattern did not indicate any Ag peaks, weak peaks of Ag3Sn were observed at 2θ of 37.60° and 39.59°, corresponding to diffraction planes (020) and (211), respectively. The electrical resistivity of the SAC305 thin film deposited on the SiO2 substrate and of the bulk SAC305 samples were measured as 19.6 and 13.7 μΩ cm, respectively. It was noted that changes in hold time at peak loads or the rate of loading in the creep experiments did not significantly influence the creep properties of the SAC305 bulk or thin film material.

P-/n-Type Switching in the Ag/BTO/TiO2 Nanocomposite as a Gas Sensor toward Ethanol, Liquefied Petroleum Gas, and Ammonia.

A novel Ag/BTO/TiO2 nanocomposite was prepared using chemical reduction and sol-gel techniques followed by sintering at ∼950 °C to grow rutile TiO2 and remove organic materials and hydroxyl groups. The structural, optical, morphological, dielectric, and gas-sensing properties were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductance, capacitance, and resistance meter, respectively. The surface plasmon resonance peak of Ag was observed at 428 nm, and the absorption edge of the Ag/BTO/TiO2 nanocomposite was observed at 235 nm, with an energy bandgap of 5.42 eV. The dielectric constant is lower at 25 °C and becomes highest at 350 °C and low frequency. The percentage response is better toward ammonia than ethanol and liquefied petroleum gas (LPG) at 25 °C, while it is greater, ∼87%, for LPG at a higher temperature. The p-/n-type switching and vice versa were recorded in the whole gas-sensing measurement. During response-recovery time, the device performed as n type for ethanol and ammonia and p type for LPG, with a very fast response time of ∼4 s for all gases. The recovery time for ethanol was achieved at 20-25 s, while for LPG and ammonia, it was ∼60 s. Moreover, the negative and positive activation energies also confirm the switching behavior in the novel Ag/BTO/TiO2 nanocomposite.

Preparation and antibacterial activity of mesoporous silica based on rice husk ash

Rice husk ash (RHA) is a widely discarded agricultural by-product, leading to environmental and health concerns due to its low density. In this study, we employed a hydrothermal reaction coupled with univariate and multi-parameter response surface method optimization to extract silicon, the key component, and prepare mesoporous silica (mSiO2) from RHA. Furthermore, silver nanoparticles (Ag-NPs) were synthesized in situ in the pores of mSiO2 to prepare mSiO2@Ag nanocomposites. The morphology, structure and composition of the prepared mSiO2@Ag were characterized using TEM, FT-IR, UV–Vis and XRD. To evaluate their antibacterial properties, Staphylococcus aureus and Escherichia coli were employed as model strains. The results revealed that the average particle size of the prepared mSiO2 and mSiO2@Ag nanocomposites were 98 nm (PDI = 0.023) and 278 nm (PDI = 0.062), respectively. The FT-IR and XRD analysis confirmed the presence of SiO2, Ag, and Ag2O characteristic peaks. The specific surface area and pore diameter of the mSiO2 were measured as 305 m2/g and 4 nm, respectively, whereas those of the mSiO2@Ag were significantly reduced. Remarkably, the mSiO2@Ag exhibited notable antibacterial activity, with MIC of 150 μg/mL and 200 μg/mL against S. aureus and E. coli, respectively. This research provides a novel avenue for the high-value utilization of RHA.

Synthesis of Ag−/Graphene Aerogel Composite for Removal of Methyl Orange

AbstractIn this study, silver‐titanium dioxide/graphene aerogel (Ag−TiO2/GA−ATG) was synthesized via chemical reduction using ethylene diamine (EDA). The effects of reductant doses on the formation of the three‐dimensional structure and the photocatalytic degradation efficiency of ATG were evaluated with five different volumes (20, 30, 40, 50, and 60 μL), corresponding to the ATG1, ATG2, ATG3, and ATG4, respectively. The results showed that 40 μL of EDA was the suitable condition for the formation of ATG three‐dimensional structure. Characterizations revealed that ATG3 was successfully synthesized with distinctive peaks of Ag and TiO2 in the X‐ray diffraction patterns whilst scanning electron microscope and high resolution transmission electron microscope images showed a porous structure, silver nanoparticles and TiO2 with an average size of 10–25 nm were uniformly distributed on the graphene surface. Furthermore, ATG3 possessed the highest photocatalytic capability to deteriorate methyl orange with an efficiency of up to 99.53 % with a catalyst dose of 0.3 mg/mL, superior compared to those of TiO2 and TiO2/GA. The radicals scavenging experiments elucidated ⋅ to majorly contribute to the photodegradation process. Moreover, ATG3 showed high recyclability, which retains 80 % of yield even after 10 cycles. Those findings proved that ATG has high potential in the environmental remediation field.

Preparation and evaluation of some nanocarbon (NC) based composites for optoelectronic applications

Polyaniline/nanocarbon (PANI/NC) nanocomposites have been prepared by in situ polymerization of aniline monomer in the presence of a stable colloidal solution of nanocarbon NC using ammonium persulfate as an initiator and silver ions (Ag+) as oxidizing agents to produce PANI/NC and PANI/NC/Ag2O nanocomposites, respectively. The morphological studies of the formed nanocomposites have been elucidated via transmission and scanning electron microscopes (TEM and SEM). Further characterization of the prepared nanocomposites has been done via infrared spectroscopy (IR), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), particle size distribution analysis (PSD), fluorescence microscope (FM), UV–VIS spectroscopy, and finally surface analysis. XRD results confirmed the presence of silver oxide Ag2O nanoparticles, and the obtained data is well matched with the JCPDS card number 76–1393 of silver oxide. XPS analyses have shown two prevailing characteristic peaks for Ag 3d5/2 and Ag 3d3/2 at 367.1 and 373 eV, respectively, representing Ag2O nanoparticles, which are matchable with the XRD analysis. The PSD analysis revealed that the sizes of the prepared nanocomposites are in the size range from 60 to 140 nm. The FM measurements showed luminescence from the prepared nanocomposites upon irradiation with different lights. This recommends that the fluorophores present in the prepared nanocomposites have the potential to both absorb and emit light. The AC conductivity and the dielectric permittivity of the obtained nanocomposites at room temperature and at different frequency ranges have been investigated. At higher frequency ranges, the maximum ac conductivity obtained was 1.06 × 10–2 and 2.5 × 10–2 S.Cm-1 for the PANI/NC and PANI/NC/Ag2O, respectively. As far as we know, these new nanocomposites with superior optical and electrical characteristics have not been described yet in the literature.

Biological fouling and corrosion resistance of Ni-based coating on AH32

ABSTRACT To reduce the destruction of organic biological fouling in marine steel, nickel-based (NiCrAlY) transition coatings with and without silver (Ag) doping were prepared on AH32 marine steel by plasma spraying. The coatings exhibited a layered structure, and AlNi3 (111), (200), and (220) diffraction peaks were detected. The Ag (111) peaks were also observed for the Ag-doped coatings. The number of sulphate-reducing bacteria (SRB) adsorbed on the coating surfaces reduced after immersion in the bacterial solution, and their shells were disintegrated because of the presence of Ag. The corrosion potentials of AH32, NiCrAlY, and NiCrAlY(Ag) coated AH32 plates were nearly identical at approximately −720 mV. After being covered with organic paint, the corrosion potential and current density of the NiCrAlY(Ag) coating increased to −624 mV and decreased by one order of 2.75 × 10− 6 A cm−2, respectively. The NiCrAlY(Ag) coating effectively inhibited biological fouling.