Fe Bimetallic Nanoparticles Research Articles

Syzygium aromaticum Bud Extracted Core–Shell Ag–Fe Bimetallic Nanoparticles: Phytotoxic, Antioxidant, Insecticidal, and Antibacterial Properties

Today, there is the roar of sustainable material development around the globe. Green nanotechnology is one of the extensions of sustainability. Due to its sustainable approach, the green fabrication of nanoparticles has recently surpassed their classical synthesis in popularity. Among metal nanoparticles, contemporary findings have demonstrated that bimetallic nanoparticles possess more potential for different applications than monometallic nanoparticles due to the synergistic effects of the two metals. So, we are presenting facile, one-vessel, and one-step phyto-fabrication of Ag–Fe BMNPs using the bud extract of Syzygiumaromaticum. The synthesized nanoparticles were characterized by UV-VIS, XRD, EDX, FTIR, and SEM. The synthesized NPs and the extract underwent biological studies. The radical scavenging potential of the NPs and the extract was found to be 64% and 73%, and the insecticidal potential was found to be 80% and 100%, respectively. Similarly, the NPs and the extract both exhibited good antibacterial activity. The zone of inhibition using 100 mg/mL of extract and NPs was found to be 1 cm against all bacterial species, i.e., K. pneumonia, E. coli, and S. aureus. It was 1.5 cm, 1.3 cm, and 1 cm against K. pneumonia, E. coli, and S. aureus, respectively, showing that the antibacterial activity of the extract is higher than that of the NPs. So, this study unlocks the synthesis of Ag–Fe bimetallic nanoparticles using eco-safe, cost-effective, facile, and least-harmful green methodology with potential applications of both NPs and SA extract in medical and agricultural fields, a step towards sustainability.

Electrochemical Activation Applied to Perovskite Titanate Fibers to Yield Supported Alloy Nanoparticles for Electrocatalytic Application.

Active bi-metallic nanoparticles are of key importance in catalysis and renewable energy. Here, the in situ formation of bi-metallic nanoparticles is investigated by exsolution on 200nm diameter perovskite fibers. The B-site co-doped perovskite fibers display a high degree of exsolution, decorated with NiCo or Ni3 Fe bi-metallic nanoparticles with average diameter about 29 and 35nm, respectively. The perovskite fibers are utilized as cathode materials in pure CO2 electrolysis cells due to their redox stability in the CO/CO2 atmosphere. After in situ electrochemical switching, the nanoparticles exsolved from the perovskite fiber demonstrate an enhanced performance in pure CO2 electrolysis. At 900°C, the current density of solid oxide electrolysis cell (SOEC) with 200µm YSZ electrolyte supported NiFe doped perovskite fiber anode reaches 0.75Acm-2 at 1.6V superior to the NiCo doped perovskite fiber anode (about 1.5 times) in pure CO2 . According to DFT calculations (PBE-D3 level) the superior CO2 conversion on NiFe compared to NiCo bi-metallic species is related to an enhanced driving force for C-O cleavage under formation of CO chemisorbed on the nanoparticle and a reduced binding energy of CO required to release this product.

Pd–Fe bimetallic nanoparticles anchored on N-doped carbon-modified graphene for efficient catalytic organic reactions

Pd–Fe bimetallic nanoparticles anchored on N-doped carbon-modified graphene for efficient catalytic organic reactions

An atomistic study on the structural and thermodynamic properties of Al–Fe bimetallic nanoparticles during melting and solidification: The role of size and composition

Multimetallic nanoparticles (NPs) are emerging as critical nanomaterials in different fields, due to their unique physicochemical properties. In particular, bimetallic NPs provide a precise platform for controlling thermophysical properties with high sensitivity and broad versatility. In this work, the importance of size and composition in the structural and thermodynamic properties of Al–Fe bimetallic NPs are studied using molecular dynamics simulations. Relevant quantities are used to describe their melting and solidification behavior. Our results indicate a linear character of the melting temperature as a function of the inverse nanoparticle size for Al, Fe, and Al50Fe50 NPs. These values were estimated using the calorific curve and heat capacity. Furthermore, body-centered cubic, hexagonal close-packed, and local icosahedral structures are observed at room temperature in cooled Al50Fe50 NPs for sizes greater than a thousand atoms. Moreover, the cohesive energy, nanoparticle radius, and surface effect of Al50Fe50 NPs roughly reproduce the scaling law. Composition effects reveal that structural identification and atomic mobility of Al and Fe atoms strongly depend on the composition x in (Al100−xFex)N NPs. Also, it is found that the melting temperature can be tuned with the size and composition. On the other hand, the liquid-to-crystalline phase transition is extensively influenced by the Fe composition for cooled Al100−xFex NPs. Additionally, the cohesive energy and the nanoparticle radius show a quadratic dependence with composition. Finally, we have found several Al100−xFex NPs, which are stable at room temperature. The possibility to control the concentration in these NPs opens up potential applications in catalysis, magnetism, for hydrogen storage, or as an additive for aircraft coatings.

Green Synthesis, Characterization and Antimicrobial Potency of Ag–Fe Bimetallic Nanoparticles from Papaya Leaf Extract

Due to their new physical and chemical properties derived from synergistic effects between the two metals, Bimetallic nanomaterials have raised more and more significant concern from worldwide researchers in recent years.

Synthesis and design of Ag\u2013Fe bimetallic nanoparticles as antimicrobial synergistic combination therapies against clinically relevant pathogens

The inappropriate use of antibiotics and the inadequate control of infections have led to the emergence of drug-resistant strains. In recent years, metallo-pharmaceutics and metallic nanoparticles have been proposed as potential alternative antimicrobials due to their broad-spectrum antimicrobial properties. Moreover, recent findings have shown that combinations of transition metal compounds can exhibit synergistic antimicrobial properties. Therefore, the synthesis and design of bimetallic nanoparticles is a field worth exploring to harness the interactions between groups of metals and organic complex structures found in different microbial targets, towards the development of more efficient combinatorial antimicrobials composed of synergistic metals. In this study, we present a green synthesis of Ag–Fe bimetallic nanoparticles using an aqueous extract from the leaves of Gardenia jasminoides. The characterization of the nanoparticles demonstrated that the synthesis methodology produces homogenously distributed core–shell Ag–Fe structures with spherical shapes and average diameter sizes of 13 nm (± 6.3 nm). The Ag–Fe bimetallic nanoparticles showed magnetic and antimicrobial properties; the latter were evaluated against six different, clinically relevant multi-drug-resistant microbial strains. The Ag–Fe bimetallic nanoparticles exhibited an antimicrobial (bactericidal) synergistic effect between the two metals composing the bimetallic nanoparticles compared to the effects of the mono-metallic nanoparticles against yeast and both Gram-positive and Gram-negative multidrug-resistant bacteria. Our results provide insight towards the design of bimetallic nanoparticles, synthesized through green chemistry methodologies, to develop synergistic combinatorial antimicrobials with possible applications in both industrial processes and the treatment of infections caused by clinically relevant drug-resistant strains.

Facile one-pot green synthesis of Ag–Fe bimetallic nanoparticles and their catalytic capability for 4-nitrophenol reduction

The synergy between two different metals provides a dramatic enhancement in the bimetallic nanoparticles' catalytic properties since bimetallization improves the properties associated with the presence of two individual metals. Therefore, herein, we reported the facile, seedless, one-pot green synthesis of Ag–Fe bimetallic nanoparticles via reduction process using phytochemicals present in the Salvia officinalis aqueous extract. During the Phyto-assisted nanofabrication of Ag–Fe nanoparticles, the reduction of Ag+ and Fe3+ metal ions to Ag–Fe NPs takes place according to their reduction potential. The UV–visible spectroscopic technique was initially used for the Ag–Fe nanoparticle formation in which the absorption band at 450 nm, 350 nm, and 352 nm were observed for AgNPs, FeNPs, and Ag–Fe nanoparticles, respectively. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis were used to investigate the size and shape of biosynthesized Ag–Fe nanoparticles, and it was revealed that the as-synthesized Ag–Fe nanoparticles are nearly spherical with an average size of 30 nm. X-ray diffraction (XRD) study was carried out to analyze the purity of the Ag–Fe nanoparticles. Fourier transform infrared spectroscopy (FTIR) analysis was performed to confirm the role of reducing and capping/stabilizing agents in the synthesis of Ag–Fe bimetallic nanoparticles. The successful biosynthesis of Ag–Fe nanoparticles was also confirmed by X-ray energy-dispersive spectrometry (EDX) analysis. Thermogravimetric analysis (TGA) was used to investigate the decomposition pattern of the Ag–Fe bimetallic nanoparticles. The catalytic behavior of as-synthesized Ag–Fe nanoparticles was investigated for the catalytic degradation of 4-nitrophenol to 4-aminophenol. The observed results revealed that Ag–Fe nanoparticles showed an efficient reduction of 4-Nitrophenol (4-NP) to 4-Aminophemol (4-AP) after 45 min of treatment.

Enhancement of anodic oxidation of formic acid on Pd–Fe bimetallic nanoparticles by thermal treatment

The surface composition and catalytic properties of Pd–Fe bimetallic catalysts with identical bulk composition can be continuously tuned by treatment at different temperatures. The activity of these catalysts in formic acid oxidation was related to the treatment temperature. The thermal treatment temperatures ranged from 400 to 600 °C. The Pd–Fe nanoparticles are characterized by an array of analytical techniques including TEM (transmission electron microscopy), XRD (X-ray diffraction), ICP (inductively coupled plasma) and HS-LEIS (low energy ion scattering spectroscopy). The electrocatalytic activity is examined using cyclic voltammetric and chronoamperometric measurements. The Pd–Fe/C catalyst with 500 °C shows the highest electrocatalytic activity for formic acid oxidation, with a current activity 3 times higher than that of before treated Pd–Fe/C catalyst, 5.6 times higher than that of commercial Pt/C catalyst. The migration of Pd to the surface on the nanoparticle catalysts as well as the electrochemical active surface area of the PdFe–H catalysts was shown to play a major role in enhancing the electrocatalytic activity for catalyst. These findings provided important insights into the correlation between the electrocatalytic activity and the treatment temperature of the nanoengineered bimetallic catalysts.

Phytogenic Fabrication of Ag-Fe Bimetallic Nanoparticles for Cell Cycle Arrest and Apoptosis Signaling Pathways in Candida auris by Generating Oxidative Stress.

Novel green synthetic nanomedicines have been recognized as alternative therapies with the potential to be antifungal agents. Apoptosis induction, cell cycle arrest and activation of the antioxidant defense system in fungal cells have also gained attention as emerging drug targets. In this study, a facile and biodegradable synthetic route was developed to prepare Ag–Fe bimetallic nanoparticles using aqueous extract of Beta vulgaris L. Surface plasmon resonance of Beta vulgaris-assisted AgNPs nanoparticles was not observed in the UV-visible region of Ag–Fe bimetallic NPs, which confirms the formation of Ag–Fe nanoparticles. Beta vulgaris-assisted Ag–Fe NPs were characterized by FTIR spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and TGA-DTG analysis for their structural and morphological properties. The as-prepared Ag–Fe NPs were well dispersed and spherical with the average particle size of 15 nm. The antifungal activity of these Ag–Fe NPs against clinical isolates of Candida auris was determined by broth microdilution and cell viability assays. For insights into mechanisms, induction of apoptosis and triggering cell cycle arrest were studied following standard protocols. Furthermore, analysis of antioxidant defense enzymes was determined spectrophotometrically. Antifungal susceptibility results revealed high antifungal activity with MIC values ranging from 0.19 to 0.39 µg/mL. Further studies showed that Ag–Fe NPs were able to induce apoptosis, cell cycle arrest in G2/M phase and disturbances in primary and secondary antioxidant enzymes. This study presents the potential of Ag–Fe NPs to inhibit and potentially eradicate C. auris by inducing apoptosis, cell cycle arrest and increased levels of oxidative stress.

Nitrogen-doped carbon nanotubes encapsulating Fe/Zn nanoparticles as a persulfate activator for sulfamethoxazole degradation: role of encapsulated bimetallic nanoparticles and nonradical reaction

In this work, the carbon nanotubes (CNTs) encapsulating Zn and Fe bimetallic nanoparticles (FeZn@NC) were synthesized through a one-pot pyrolytic strategy.

Synthesis of chitosan-stabilised bimetallic nanoparticles containing Fe and Ni and the reductive degradation of nimesulide

Chitosan (CHI)-stabilised Ni–Fe bimetallic nanoparticles (bNP/CHI) were synthesised varying the content of nickel and denoted as 2-bNP/CHI, 17-bNP/CHI, and 27-bNP/CHI. The nanoparticles were characterised using several techniques and used in the removal of nimesulide. XRD and Mössbauer analyses confirmed the formation of an amorphous structure containing Fe0 and Fe2O3 while the FT-IR analysis confirmed the presence of chitosan in the nanoparticles. A very high removal of nimesulide was obtained after only 15 min of treatment with the 17-bNP/CHI system. The by-product obtained after the reductive treatment was identified using the chromatography analysis coupled to the mass spectrometry technique.

Surfactant-free Pd–Fe nanoparticles supported on reduced graphene oxide as nanocatalyst for formic acid oxidation

Herein, a novel surfactant-free nanocatalyst of Pd–Fe bimetallic nanoparticles (NPs) supported on the reduced graphene oxide (Pd–Fe/RGO) were synthesized using a two-step reduction in aqueous phase. Electrochemical studies demonstrate that the nanocatalyst exhibits superior catalytic activity towards the formic acid oxidation with high stability due to the synergic effect of Pd–Fe and RGO. The optimized Pd–Fe/RGO (Pd:Fe = 1:5) nanocatalyst possess an specific activity of 2.72 mA cm−2 and an mass activity of 1.0 A mg−1(Pd), which are significantly higher than those of Pd/RGO and commercial Pd/C catalysts.

Selenium reduction on Ni–Fe bimetallic nanoparticles: effect of process variables on reaction rates

Selenium reduction on Ni–Fe bimetallic nanoparticles: effect of process variables on reaction rates

Unraveling the roles of iron in stabilizing the defective graphene-supported Pt[sbnd]Fe bimetallic nanoparticles

The adsorption behaviors of PtnFe(55-n) (n = 0, 11, 13, 18, 28, 37, 42, 44, 55) nanoparticles (NPs) on single vacancy graphene (SVG) were studied using density functional theory. It is found that the PtFe bimetallic NPs prefer to be adsorbed on the SVG through the Fe atoms when Pt and Fe atoms are both on the surfaces, because the interactions between Fe atoms and SVG are stronger than those between Pt atoms and SVG. Based on the density of states, molecular orbital and charge difference density analyses, the Fe atoms in the NPs can strongly interact with the sp2 dangling bonds and the π orbitals near the vacancy in the SVG at the same time. The interactions between the Pt atoms and the π orbitals are very weak. Meanwhile, due to the interactions between the Pt and Fe, the d-band centers of the Pt and Fe atoms in the NPs shift to lower energy, and the adsorption energies of PtnFe(55-n) (n = 18, 37, 42 and 44) NPs on the SVG are decreased compared with that of Pt55.

Atomic structure and thermal stability of Pt–Fe bimetallic nanoparticles: from alloy to core/shell architectures

Bimetallic nanoparticles comprising noble metal and non-noble metal have attracted intense interest over the past few decades due to their low cost and significantly enhanced catalytic performances. In this article, we have explored the atomic structure and thermal stability of Pt-Fe alloy and core-shell nanoparticles by molecular dynamics simulations. In Fe-core/Pt-shell nanoparticles, Fe with three different structures, i.e., body-centered cubic (bcc), face-centered cubic (fcc), and amorphous phases, has been considered. Our results show that Pt-Fe alloy is the most stable configuration among the four types of bimetallic nanoparticles. It has been discovered that the amorphous Fe cannot stably exist in the core and preferentially transforms into the fcc phase. The phase transition from bcc to hexagonal close packed (hcp) has also been observed in bcc-Fe-core/Pt-shell nanoparticles. In contrast, Fe with the fcc structure is the most preferred as the core component. These findings are helpful for understanding the structure-property relationships of Pt-Fe bimetallic nanoparticles, and are also of significance to the synthesis and application of noble metal based nanoparticle catalysts.

FeSBA-15-supported ruthenium catalyst for the selective hydrogenolysis of carboxylic acids to alcoholic chemicals

Ordered mesoporous FeSBA-15-supported Ru catalysts are characterized by N2 adsorption–desorption isotherm, H2-temperature-programmed reduction, X-ray fluorescence, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy analyses. Results suggest the co-existence of Fe oxide species highly dispersed in the frameworks of SBA-15 and Ru–Fe bimetallic nanoparticles. The concentration of Fe species is low and in the form of Ru–Fe alloys located on the catalyst surfaces following reduction pretreatment in 5% H2–95% N2 flow at 623K for 4h. The as-reduced Ru/FeSBA-15 catalysts efficiently and selectively hydrogenolyze short-chain carboxylic acids (e.g., acetic acid, propionic acid, butyric acid, levulinic acid, and lactic acid) to their corresponding alcoholic chemicals. Results indicate that 2% Ru/FeSBA-15 catalyst with 1.07% Fe content yields the highest performance and excellent stability, yielding 92.5% conversion of acetic acid and 85.2% selectivity to ethanol under optimized conditions. The improved catalytic performance of the FeSBA-15-supported Ru catalyst is mainly attributed to the coherent interactions between Fe and Ru species, as well as to the high dispersion of Fe oxides in the SBA-15 framework.

Theoretical Investigation on Debromination Model of Deca- BromoDiphenyl Ester (BDE209)

The debromination of deca-bromodiphenyl ester (BDE209) is one of the most important processes in its removal from the environment. Despite numerous experimental studies improved the efficiency of poly brominated diphenyl ethers (PBDEs’) debromination, few studies focused on the mechanism. This work provides a preliminary investigation on studying the debromination mechanism of BDE209 with density functional theory (DFT). Experimental results suggest a stepwise process catalyzed by Ni⁄Fe bimetallic nano particles. So, a potential debromination mechanism of BDE209 via a four-membered ring transition state has been proposed. The B3LYP calculations indicate lower activation energies catalyzed by Ni relative to Fe, which agrees with the experimental result that a much higher debromination efficiency with Ni⁄Fe bimetallic nano particles than nano zero-valent iron. Also water has small solvent effect on the activation energies of debromination. The efficiency of debromination improves greatly in solvent mixture with higher ratio of water in experiment probably because of more protons provided by more water for the corrosion and debromination. Finally, the meta-bromine atoms are the most susceptible to be debrominated. Keywords: Deca-bromodiphenyl ester (BDE209), Debromination mechanism, Fe⁄Ni bimetallic nano particles, Density functional theory (DFT), Catalytic capacity.

Solid state reaction synthesis of NiFe 2O 4 nanoparticles

Ni-ferrite (NiFe 2O 4) nanoparticles have been synthesized via a solid state reaction process. Ni and Fe bi-metallic nanoparticles in the form of Ni 33Fe 67 alloy nanopowder are first synthesized by simultaneous evaporation of the required amounts of pure Ni and Fe metals followed by rapid condensation of the evaporated metal flux into solid state by means of an inert gas, helium, using the process of inert gas condensation (IGC). In order to form the NiFe 2O 4 structure, as-synthesized samples (Ni 33Fe 67) are annealed for 12 h in ambient conditions at different annealing temperatures. Structural analyses show that NiFe 2O 4 starts to form at around 450 °C and gets progressively well defined with increasing annealing temperatures yielding particle with size ranging between 15 and 50 nm. Besides successfully forming NiFe 2O 4, NiO/Fe 3O 4 core/shell nanoparticles have also been synthesized by adjusting the annealing conditions. Three different structures, Ni 33Fe 67, NiO/Fe 3O 4, and NiFe 2O 4, obtained in this study are compared with respect to their structural and magnetic properties.