NiFe Nanoparticles Research Articles

Ni3fe Nanoparticles Encapsulated by N-Doped Carbon Derived from Mofs for Oxygen Evolution Reaction

Ni3fe Nanoparticles Encapsulated by N-Doped Carbon Derived from Mofs for Oxygen Evolution Reaction

Well-Dispersed Ni3fe Nanoparticles with N-Doped Porous Carbon Shell for Highly Efficient Rechargeable Zn-Air Batteries

Well-Dispersed Ni3fe Nanoparticles with N-Doped Porous Carbon Shell for Highly Efficient Rechargeable Zn-Air Batteries

NiFe nanoparticles supported on N-doped graphene hollow spheres entangled with self-grown N-doped carbon nanotubes for liquid electrolyte/flexible all-solid-state rechargeable zinc–air batteries

NiFe alloy NPs anchored in NGHS wrapped with self-grown NCNTs with a three-dimensional architecture was constructed successfully for ORR/OER bifunctional catalysis.

Deep eutectic solvent-induced synthesis of Ni–Fe catalyst with excellent mass activity and stability for water oxidation

Ni–Fe bimetallic electrodes are currently recognized as a kind of benchmark transition metal-based oxygen evolution reaction (OER) electrocatalysts. Facile synthesis of Ni–Fe bimetallic electrode materials with excellent catalytic activity and satisfied stability by a simple and low-cost route is still a big challenge. Herein, well-defined Ni–Fe nanoparticles in-situ developed on a planar Fe substrate (Ni–Fe NPs/Fe) is fabricated via a facile one-step galvanic replacement reaction (GRR) carried out in an Ethaline-based deep eutectic solvent (DES). The prepared Ni–Fe NPs/Fe exhibits outstanding OER performance, which needs an overpotential of only 319 mV to drive a current density of 10 mA cm−2, with a small Tafel slope of 41.2 mV dec−1 in 1.0 mol L−1 KOH, high mass activity (up to 319.78 A g−1 at an overpotential of 300 mV) and robust durability for 200 h. Impressively, the Ni–Fe bimetallic oxygen-evolution electrode obtained from the Ethaline-based DES is catalytically more active and durable than that of its counterpart derived from the 4.2 mol L−1 NaCl aqueous solution. The reason for this is mainly related to the different morphology and surface state of the Ni–Fe catalysts obtained from these different solvent environments, particularly for the differences in phy–chemical properties, active species formed and deposition kinetics, offered by the Ethaline-based DES.

Fe3N@N-doped graphene as a lithiophilic interlayer for highly stable lithium metal batteries

Lithium (Li) metal anode is of great importance for high-energy rechargeable batteries owing to its ultrahigh theoretical capacity. However, the Li dendrite growth during the repetitive charge/discharge process will impale the separator resulting in short-circuiting and serious safety issues. To effectively suppress Li dendrite growth, for the first time we present a novel lithiophilic interlayer on commercial PP separator, which is constructed by Fe3N nanoparticles embedded and wrapped in N-doped graphene nanosheets (Fe3N@NG). The Fe3N@NG functionalized separator displays excellent electrolyte wettability, high Li ionic conductivity and ion transference number, which function synergistically to suppress Li dendrite growth. Meanwhile, the DFT calculation demonstrates that there exists a stronger interaction between Li atoms and Fe3N@NG, which can provide the deposition sites, resulting in uniform and compact Li plating. Above ameliorating merits accompany an ultra-long-life of 2300 h at 5 mA cm−2 for the Li//Li symmetric cells with Fe3N@NG functionalized separators. Moreover, the Li//LFePO4 full cell delivers superior long-term cyclic stability and ultralow capacity decay rate of 0.08%/cycle even at 2C. This work provides an innovative strategy to rationally design and new insights towards functional lithiophilic interlayer to efficiently suppress Li dendrite growth for Li metal batteries.

Interface coating of iron nitride on carbon cloth for reversible lithium redox in rechargeable battery

The increasing demands for high-performance energy storage devices have driven to develop advanced lithium batteries. However, the dendrite growth with potential safety issues greatly restricted the practical applications. Herein, the iron nitride (Fe2N) nanoparticles were anchored on carbon cloth to regulate the surface lithiophilic properties based on the theoretical prediction and experimental examination. Typically, the in-situ formation of highly porous Fe2N coating layer bridging between carbon cloth and lithium is able to regulate the interface properties of three-dimensional composite electrodes for reversible deposition and stripping of Li. The theoretical calculation revealed that Fe2N nanoparticles as lithiophilic sites would induce the uniform Li deposition due to the favorable electron transfer. Therefore, the composite Li electrode exhibited a good long-cycling performance of 1000 h in symmetric cells. When paired with LiNi0.5Co0.2Mn0.3O2 (NCM 523) and 3DC@I2 cathodes, the full cells delivered reversible capacities of 110 mAh g−1 for 200 cycles, and 140 mAh g−1 after 5000 cycles, respectively. This work gains the new insights into the efficient regulation of interface properties via the metal nitride coating to stabilize the lithium metal anode with enhanced reversibility.

Emerging anode materials architectured with NiCoFe ternary alloy nanoparticles for ethane-fueled protonic ceramic fuel cells

Ethane can be electrochemically dehydrogenated and converted into electric energy via protonic ceramic fuel cells to obtain highly selective chemical ethylene without producing carbon oxides. This novel conversion path relies on a highly catalytically active anode for promote the cracking of ethane. In responding to this requirement, a previously characterized anode material (La 0.6 Sr 0.4 ) 0.95 Fe 0.9 Mo 0.1 O 3-δ (LSFM) is modified by doping with active metals (Ni and Co) at the B-site of a perovskite structure. The (La 0.6 Sr 0.4 ) 0.95 Fe 0.7 Ni 0.2 Mo 0.1 O 3-δ (LSFNM), (La 0.6 Sr 0.4 ) 0.95 Fe 0.7 Co 0.2 Mo 0.1 O 3-δ (LSFCM) and (La 0.6 Sr 0.4 ) 0.95 Fe 0.7 Co 0.1 Ni 0.1 Mo 0.1 O 3-δ (LSFCNM) electrode materials are synthesized by the combustion method. The subsequent in situ exsolution of the FeNi, CoFe and NiCoFe alloy nanoparticles in a reducing atmosphere improves the catalytic performance of the resultant electrodes. The obtained data show that the maximum power densities of single cells constructed using LSFCNM as an anode material at 750 °C reach 328 mW cm −2 and 258 mW cm −2 in H 2 and C 2 H 6 , respectively. Meanwhile, the ethane conversion process yields ∼44% under a constant current. The significantly higher performance of these cells than that achieved with single cells using LSFNM and LSFCM as anode materials, respectively, indicate that the NiCoFe ternary alloy offers better synergistic catalytic activity than that of the CoFe and FeNi binary alloys. •In situ precipitation ternary alloys by doping active metals Ni and Co elements. •The segregation of nanoparticles obtains abundant active oxygen vacancies. •The thermal catalytic and electrochemical properties are significantly improved. •Ethylene and electricity can be coproduced in ethane-fueled protonic ceramic fuel cells.

Condensation of cometary silicate dust using an induction thermal plasma system

Glass with embedded metal and sulfides (GEMS) is a major component of chondritic porous interplanetary dust particles. Although GEMS is one of the most primitive components in the Solar System, its formation process and conditions have not been constrained. We performed condensation experiments of gases in the system of Mg–Si–O (MgSiO3 composition) and of the S-free CI chondritic composition (Si–Mg–Fe–Na–Al–Ca–Ni–O system) in induction thermal plasma equipment. Amorphous Mg-silicate particles condensed in the experiments of the Mg–Si–O system, and their grain size distribution depended on the experimental conditions (mainly partial pressure of SiO). In the CI chondritic composition experiments, irregularly shaped amorphous silicate particles of less than a few hundred nanometers embedded with multiple Fe–Ni nanoparticles of ≤20 nm were successfully synthesized. These characteristics are very similar to those of GEMS, except for the presence of FeSi instead of sulfide grains. We propose that the condensation of amorphous silicate grains smaller than a few tens of nanometers and with metallic cores, followed by coagulation, could be the precursor material that forms GEMS prior to sulfidation.

Aerosol‐assisted synthesis of bimetallic nanoparticle‐loaded bamboo‐like N‐doped carbon nanotubes as an efficient bifunctional oxygen catalyst for Zn‐air batteries

Considering fabrication of highly efficient and low-cost bifunctional oxygen electrocatalysts, which can substitute noble metal-based catalysts, is imperative for advanced rechargeable Zn-air batteries (ZABs). Among the various candidates, N-doped carbon and transition metal composite catalyst is considered as promising bifunctional oxygen electrocatalysts. In this study, one-dimensional structured bamboo-like N-doped carbon nanotubes (bNCNTs) were synthesized by spray pyrolysis followed by a post-treatment. CoFe nanoalloys embedded within SiO2 microspheres were employed as a nanocatalyst to grow homogeneous bNCNTs, which have known as excellent oxygen reduction reaction (ORR) activity. To compensate for the low oxygen evolution reaction (OER) activity of bNCNTs, NiFe nanoparticles were loaded on bNCNTs (NiFe/bNCNT) by a “drop and dry” process and post-treatment. Synergistic effect arising from bNCNTs showing high surface area and controlled infiltration method, NiFe nanoparticles exhibited high dispersity on bNCNTs. Owing to the synergistic effect of NiFe metal nanoparticles and bNCNTs, NiFe/bNCNT exhibited superior ORR properties with a high limiting current density (5.1 mA cm−2) and a low Tafel slope (94 mV dec−1), as well as outstanding OER activity with a low overpotential (350 mV) in an alkaline media compared to those of single metal-loaded bNCNTs and Pt/C-RuO2. Furthermore, when applied as ZAB cathode catalyst, NiFe/bNCNT demonstrated a high power density (224 mW cm−2) and 330 hours long cycling stability.

Synthesis of Nickel Spinel Ferrites Nanoparticles Coated with Thermally Reduced Graphene Oxide for EMI Shielding in the Microwave, UV, and NIR Regions.

The co-precipitation and in situ modified Hummers’ method was used to synthesize Nickel Spinal Ferrites (NiFe) nanoparticles and NiFe coated with Thermally Reduced Graphene Oxide (TRGO) (NiFe-TRGO) nanoparticles, respectively. By using polyvinyl chloride (PVC), tetrahydrofuran (THF), and NiFe-TRGO, the nanocomposite film was synthesized using the solution casting technique with a thickness of 0.12–0.13 mm. Improved electromagnetic interference shielding efficiency was obtained in the 0.1–20 GHz frequency range. The initial assessment was done through XRD for the confirmation of the successful fabrication of nanoparticles and DC conductivity. The microstructure was analyzed with scanning electron microscopy. The EMI shielding was observed by incorporating a filler amount varying from 5 wt.% to 40 wt.% in three different frequency regions: microwave region (0.1 to 20 GHz), near-infrared (NIR) (700–2500 nm), and ultraviolet (UV) (200–400 nm). A maximum attenuation of 65 dB was observed with a 40% concentration of NiFe-TRGO in nanocomposite film.

A rational design of FeNi alloy nanoparticles and carbonate-decorated perovskite as a highly active and coke-resistant anode for solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are a kind of clean and efficient device to convert chemical energy in fuels into electricity. However, since anodes with high catalytic activity and carbon tolerance are still underdeveloped, the consequent serious performance degradation of the cells under operational conditions significantly confines their commercial applications. Here we propose a new strategy to remove carbon deposition by in-situ formation of alkali metal carbonate on the anode surface. A multi-phase composite anode, which is composed of an orthorhombic single perovskite main phase, a Ruddlesden-Popper (RP) layered perovskite second phase, and an in-situ exsolved FeNi alloy minor phase, is developed by one-step reduction of La0.65Li0.05Sr0.3Fe0.8Ni0.2O3-δ (LLSFN0.05) at a high temperature. The deficiencies of the RP phase and A-site caused by Li dopant would increase oxygen bulk diffusion, and FeNi nanoparticles would boost the catalytic activity. Moreover, when dealing with carbon fuel, lithium carbonate can be synthesized on the anode surface, serving as a good oxygen ion conductor and an efficient catalyst for coke removal by gasification. A single cell with our reduced LLSFN0.05 anode exhibited maximum power densities of 596, 467, and 424 mW cm−2 at 750 ℃ with H2, CO, and wet C2H6 as the fuel, respectively. In addition, the cells could have a long-term stable operation for over 80 h using CO as the fuel at 200 mA cm−2. This study provides a new material design strategy to develop a highly active and coke-resistant anode.

Constructing electrostatic self-assembled ultrathin porous red 2D g-C3N4/Fe2N Schottky catalyst for high-efficiency tetracycline removal in photo-Fenton-like processes

The traditional heterogeneous photo-Fenton reaction was mainly restricted by the fewer surface-active sites, low Fe3+/Fe2+ transformation and H2O2 activation efficiency of catalyst. This work designed and fabricated the efficient photo-Fenton Schottky catalysts via a facile electrostatic self-assembly of metallic Fe2N nanoparticles scattering on the surface of red g-C3N4 (ultrathin porous oxygen-doped 2D g-C3N4 nanosheets). The porous morphology and exceptional electrical structure of red g-C3N4 endowed more active sites and facilitated the photoexcited charge separation. Benefitting from the Schottky effect and unique dimensional coupling structure, the strong visible light absorption and fast spatial charge transfer were realized in the Schottky junction system. More strikingly, Fe2N as an efficient co-catalyst was in favor of the trap and export of e-, leading to the Fe3+/Fe2+ transformation and H2O2 activation during the photo-Fenton process. Accordingly, the as-prepared catalysts revealed outstanding activity in photo-Fenton like degradation of tetracycline (TC) although under 5 W white LED light irradiation. Furthermore, the reasonable degradation pathway of TC and corresponding toxicity of the intermediates, as well as the photo-Fenton catalytic mechanism were interpreted and discussed in detail. This study would be a great aid in the development of various Schottky catalysts for heterogeneous photo-Fenton-based environmental remediation systems.

Molecular dynamics investigation of structure evolution and thermodynamics of Ni-Fe nanoparticles during inert gas condensation.

Synthesis of magnetic nanoparticles is relevant to many applications in the fields of catalysis, energy storage, and biomedicine. Understanding the growth mechanisms and morphology of nanoparticles during inert gas condensation is crucial to rationally improve the performance of the final nanoparticles. In this work, molecular dynamics simulations are carried out to study the structural and thermodynamic behavior of Ni-Fe nanoparticles from homogenous vapor phase in Ar atmosphere. It is revealed that the final morphology of the resulting nanoparticles presents a spherical shape by cluster coalescence at high temperatures where the small clusters are liquid droplets prior to their collisions. However, probabilistic nucleation and cluster growth indicate that the occurrence of spherical shape is more controlled by the probability limits for different Fe concentrations. Meanwhile, a larger inert gas density induces a more efficient cooling effect leading to a larger probability control of the cluster formation with non-spherical shape by agglomeration. Furthermore, the solidification of the as-formed Ni-Fe clusters is examined by evaluating the evolution of crystalline and amorphous structure. The linear scaling-down dependence of the solidification temperature on the reciprocal of the nanoparticle size clearly signifies a linear size-depression effect for the liquid-to-solid phase change of Ni-Fe nanoparticles. Our findings thus extend the current understanding of inert gas condensation behavior and mechanisms of Ni-Fe nanoparticles from an atomic/molecular perspective.

High‐Temperature Nitridation Induced Carbon Nanotubes@NiFe‐Layered‐Double‐Hydroxide Nanosheets Taking as an Oxygen Evolution Reaction Electrocatalyst for CO2 Electroreduction

AbstractThe development of high‐efficiency catalysts for carbon dioxide reduction reaction (CO2RR) and oxygen evolution reactions (OER) is an important strategy to solve the current energy crisis. In this paper, solid‐phase exfoliation and electrostatic self‐assembly strategies are developed to couple ultrathin NiFe‐layered‐double‐hydroxide nanosheets and carbon nanotubes (CNT@NiFe‐LDH NS) as an OER catalyst. Then, NiFe nanoparticles anchored on the N‐doped CNT (CNT‐N‐NiFe) for electrocatalyst of CO2RR is synthesized via pyrolysis of a mixture of CNT@NiFe‐LDH NS and melamine in a nitrogen atmosphere at 750 °C, utilizing the ultrathin NiFe‐LDH NS as a metal source and CNT as the framework. CNT@NiFe‐LDH NS nanohybrid exhibits a better catalytic activity for OER (with an overpotential of 270 mV at the current density of 20 mA cm–2 and remarkably stable durability) than Bulk NiFe‐LDH in 1 m KOH. Moreover, the CNT‐N‐NiFe catalyst exhibits a Faradaic efficiency of ≈82.6% for the reduction of CO2 to CO at −0.7 V (vs reversible hydrogen electrode) with a current density of CO 10.2 mA cm–2. The method of preparing CO2RR catalysts provides a new idea of the preparation of bimetallic CO2RR electrocatalysts.

Bimetallic FeNi nanoparticles immobilized by biomass-derived hierarchically porous carbon for efficient removal of Cr(VI) from aqueous solution

Nano zero-valent iron (nZVI) is an effective material for Cr(VI) treatment, however excessive agglomeration and surface oxidation limit its application. Herein, straw derived hierarchically porous carbon supported FeNi bimetallic nanoparticles (FeNi@HPC) was prepared for effective removal of Cr(VI) from water. FeNi nanoparticles were successfully loaded onto HPC with good dispersibility, and HPC caused an increase in specific surface area of FeNi nanoparticles. FeNi@HPC exhibited a significantly enhanced removal efficiency for Cr(VI) in comparison to Fe@HPC and FeNi NPs. The Ni doping content was further optimized, and the best Ni content in bimetallic NPs was estimated as 10 wt%. The conditions optimal for the activity of FeNi@HPC were assessed, and the highest removal efficiency equivalent to 30 mg L−1 of Cr(VI) was achieved at pH= 4.0 in 360 min with a dosage of 0.5 g L−1. Higher temperatures favored the removal of Cr(VI) and FeNi@HPC manifested the lowest activation energy as compared to Fe@HPC and FeNi NPs. The action mechanisms of FeNi@HPC presumably involved electron transfer from Fe0, Fe2+and atomic hydrogen. This work not only provide a cost-effective and available HPC material to stabilize nZVI but also revealed that using FeNi@HPC is a promising approach for the remediation of water pollution.

Comparative study of trichloroethylene removal by different carbons and FeNi-carbon composites

Nanoscale zero-valent iron (NZVI) has been proven effective at degrading environmental ‎contaminants of concern, yet field performance as an in situ remedy is lacking due to short ‎reactive lifetimes and poor transport through porous media. The main ‎objective of this study was to investigate and compare the performance of different carbon ‎powders with different properties (surface ‎area, pore-volume, conductivity, functional groups) on trichloroethylene (TCE) removal and transport ‎properties. Carbon ‎powders were used as the support for bimetallic FeNi nanoparticles, the composites were stabilized by poly(vinyl pyrrolidone), and the performance of ‎the modified novel FeNi-carbon composites was compared. It was confirmed that several properties of the carbon were found to not affect TCE degradation by the FeNi-C composites while ‎surface area, pore size, and functional groups are responsible for TCE adsorption by carbon ‎powders. Carbon particle size was found to inversely affect the transport of the composite ‎through porous media, with smaller carbon supports such as carbon black correlating to a wider ‎radius of influence, as compared to larger biochar carbon particulates. Significantly, FeNi-C ‎shows improved TCE degradation over Fe or FeNi nanoparticles alone, indicating the utility of ‎using carbon supports to promote dehalogenation reactions and increase NZVI longevity‎.

Formation of Fe-Ni Nanoparticle Strands in Macroscopic Polymer Composites: Experiment and Simulation.

Magnetic-field-induced strand formation of ferromagnetic Fe-Ni nanoparticles in a PMMA-matrix is correlated with the intrinsic material parameters, such as magnetization, particle size, composition, and extrinsic parameters, including magnetic field strength and viscosity. Since various factors can influence strand formation, understanding the composite fabrication process that maintains the strand lengths of Fe-Ni in the generated structures is a fundamental step in predicting the resulting structures. Hence, the critical dimensions of the strands (length, width, spacing, and aspect ratio) are investigated in the experiments and simulated via different intrinsic and extrinsic parameters. Optimal parameters were found by optical microscopy measurements and finite-element simulations using COMSOL for strand formation of Fe50Ni50 nanoparticles. The anisotropic behavior of the aligned strands was successfully characterized through magnetometry measurements. Compared to the unaligned samples, the magnetically aligned strands exhibit enhanced conductivity, increasing the current by a factor of 1000.

In-situ exsolved FeNi nanoparticles on perovskite matrix anode for co-production of ethylene and power from ethane in proton conducting fuel cells

Proton-conducting solid oxide fuel cells have the potential ability to simultaneously convert ethane to electrical energy and value-added ethylene with high selectivity and the absence of CO2 emissions. However, their development is impeded by a lack of efficient and stable anode materials. Herein, in-situ exsolved FeNi nanoparticles on (La0.6Sr0.4)0.95Fe0.8Ni0.1Mo0.1O3-δ (LSFNM) perovskite oxide are realised by controlling A-site deficiency and Mo-doping. The introduction of high-valence molybdenum ions in (La0.6Sr0.4)0.95Fe0.8Ni0.2O3-δ (LSFN) not only stabilises its cubic perovskite structure under a reducing atmosphere, but also facilities the exsolution of FeNi nanoparticles from the parent perovskite matrix. The power density of the BaZr0.1Ce0.7Y0.2O3−δ (BZCY) electrolyte-supported single cells with a LSFNM/BZCY/LSCF-SDC configuration reaches 172mW•cm−2 at 750°C in C2H6; meanwhile, the ethylene yield also reaches approximately 40.5%. The presented results extend the functionality and applicability of proton conducting fuel cells for carrying out efficient hydrocarbon-related electrochemical conversion for producing power and co-production of value-added chemicals.

Synthesis and characterization of NiFe-carbon fibers by solution blow spinning and application for the oxygen evolution reaction

NiFe-carbon fibers were obtained by Solution Blow Spinning (SBS) and had their microstructure, properties and electrochemical behavior as electrocatalysts for the oxygen evolution reaction (OER) systematically studied. Transmission electron microscopy, X-ray diffraction and Mössbauer spectroscopy showed that the samples are NiFe-carbon fibers and consist of sphere-like NiFe nanoparticles (with diameters in the range 4–12 nm) uniformly dispersed in the fibrillar carbon matrix. Raman spectroscopy revealed the carbon counterpart with D and G bands showing a intensity ratio of 0.8235. The magnetic hysteresis curve at 4 and 300 K are typical of ferromagnetic material. The catalytic activity of NiFe-carbon fibers towards OER under alkaline medium showed an overpotential of 296 mV vs. RHE at J = 10 mA cm−2, and a high electrochemical stability over 15 h under an electrolysis current of J = 10 mA cm−2.

Coordination Polymer-Derived Fe3N Nanoparticles for Efficient Electrocatalytic Oxygen Evolution.

Based on a coordination polymer, FeCl2(4,4'-bpy) (4,4'-bpy = 4,4'-bipyridine) and the carbon nanotube (CNT)/NaCl dual template, Fe3N nanoparticles (NPs) were synthesized via chemical thermolysis in the absence of an extra nitrogen source. The decomposition of 4,4'-bpy under high temperature produces thin carbon coating for Fe3N NPs. Also, the CNT template anchors the Fe3N NPs to avoid aggregation. The sample (denoted as Fe3N-C N) exhibits excellent electrocatalytic oxygen evolution reaction (OER) behavior even with a small molar ratio of Fe3N (Fe: 4.9 at. %), which can deliver a current density of 10 mA cm-2 at an overpotential of 218 mV with a Tafel slope of 84 mV dec-1 and long-term OER activity during 60 h electrolysis at 20 mA cm-2. Furthermore, the sample after 20 h electrolysis, denoted as Post-Fe3N-C N (20 h), displays enhanced OER activity with a smaller Tafel slope of 41 mV dec-1 and overpotentials of 195 and 327 mV at 10 and 100 mA cm-2, respectively, which is mainly due to the partial transformation of Fe3N into FeOOH. The OER mechanism is investigated by density functional theory calculations, and it is found that the surface partial oxidation of Fe3N leads to the effective OER electrolysis, which changes the electron density of the superficial atoms and induces the moderate adsorption for the intermediates.