In this work, we present three different pathways to render commercial melamine sponges, both magnetic and hydrophobic, thereby offering them the capacity to effectively and selectively remove crude oil and heavy metals from aqueous environments.

The development of sustainable hydrogen production technologies is crucial to address the global energy crisis and reduce carbon emissions. With growing concerns over freshwater scarcity, the combination of green hydrogen production with ammonia oxidation reaction from wastewater, emerges as a highly promising strategy for meeting carbon goals and reusing treated water. Here, we report a green, scalable, room-temperature chemical reduction method for the successful synthesis of self-supported FeNiB, FeNiBP, and FeNiP electrocatalysts on nickel foams. FeNiB@NF exhibited the highest HER activity, achieving -469 mA cm-2 at -0.71 V vs. RHE with an overpotential of -0.26 V vs. RHE at -100 mA cm-2 in alkaline water and -330 mA cm-2 at -0.69 V vs. RHE and with an overpotential of -0.34 V vs. RHE at -100 mA cm-2 in ammonia-rich electrolyte, while FeNiBP@NF delivered superior OER performance of 972 mA cm-2 at 2.3 V vs. RHE and AOR performance of 963 mA cm-2 at 1.97 V vs. RHE. Physicochemical analysis further revealed that the strong reducing power of sodium borohydride was crucial in generating metallic Fe and Ni states, underpinning the outstanding activity of FeNiB@NF in HER. On the other hand, the synergistic effects of boron and phosphorus in FeNiBP@NF likely facilitated OH* and NH3* adsorption, contributing towards its high catalytic activity in OER and AOR, respectively.

This study examines the recycling potential of a ferrous-rich OBM slag generated in the ferronickel industry through hydrogen reduction (10 vol% H2 in a H2/N2 mixture) over the temperature range of 300-1000 degrees C, aiming to produce a metallic iron (Fem)-rich powder. The transformation of iron phases was characterized and quantitatively estimated using Mo & uml;ssbauer spectroscopy and X-ray diffraction (XRD) refinement. The effects of temperature, reduction duration, and hydrogen supply on the reduction progress were evaluated as independent variables. The maximum reduction degree (RD = 87%) was achieved at 800 degrees C, 240 min, and 100% H2 excess. Above this temperature, the reduction progress decreased, as evidenced by an increase in Fe2+ content instead of Fem. This behavior was attributed to the elevated pH2O/pH2 ratio in the tube reactor, considering the low flow velocity of the H2/N2 mixture (approximate to 4.0 mm & sdot;s-1). A Response Surface Methodology (RSM) model, fitted to onefactor-at-a-time (OFAT) data, suggested 920 degrees C as an indicative optimal temperature for the reduction of the OBM slag, identifying temperature as the most influential factor on the process. The enrichment behavior of the optimally reduced sample was further investigated using a tailored gravity-separation method. Following this approach, the Fe-m content increased from 70.46% to 79.4 wt%, with a corresponding iron recovery of 62.3%. The resulting reduced and beneficiated micro-powder is proposed for use as an additive in the fabrication of complex materials or as a partial feedstock alongside iron scrap in induction smelting furnaces.

In this letter, we demonstrate for the first time the preparation of bulk L1(0)-FeNi embedded in an fcc FeNi by alloying Fe and Ni during casting with 5%-10% indium metal and annealing at 350 degrees C for a week. From X-ray diffraction, magnetization, and M & ouml;ssbauer data, we have strong indications that the L1(0)-FeNi phase is formed and coexists with the cubic A1-FeNi at a ratio of 30/70 for the sample with 5% In and 20/80% for the sample with 10% In, as derived from X-ray diffraction. This finding is supported by the M & ouml;ssbauer data, where the ratio of L1(0)-FeNi to A1-FeNi is 48/52 and 24/76, respectively. The morphology of the alloys is sponge-like and very brittle, and the final In stoichiometry is much less than the nominal one.

Bimetallic colloidal CoPt nanoalloys with low platinum content were successfully synthesized following a modified polyol approach. Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) studies were performed to estimate the crystal structure, morphology, and surface functionalization of the colloids, respectively, while the room-temperature magnetic properties were measured using a vibrating sample magnetometer (VSM). The particles exhibit excellent uniformity, with a narrow size distribution, and display strong room-temperature hysteretic ferromagnetic behavior even in the as-made form. Upon annealing at elevated temperatures, progressive formation and co-existence of exchange coupled, of both chemically ordered and disordered phases significantly enhanced the room-temperature coercivity.

We examined the crystal and magnetic properties of the polymorphic LiFeO _2 compound using Mössbauer spectra (MS), X-ray diffraction data (XRD), and magnetic measurements. X-ray diffraction analysis of α -LiFeO _2 and β ' -LiFeO _2 phases reveals that short-range ordering observed in the α -LiFeO _2 phase is potentially linked to the β ' -LiFeO _2 phase nanoregions. Low-temperature MS of the α -LiFeO _2 phase reveal a complicated disordered magnetic state below 90 K. Rietveld analysis of the XRD data of the γ -LiFeO _2 phase reveals a defect microstructure. These defects produce a complicated distribution of the hyperfine magnetic field estimated from MS. While it is not possible to produce the β ' -LiFeO _2 phase in pure form, extended annealing of the α -LiFeO _2 phase at 400 ^∘ C yields a nanocomposite material comprising nanoregions of both β ' -LiFeO _2 and γ -LiFeO _2 phases.

Magnetic Fe3O4 nanoparticles "decorated" by LAPONITE® nanodisks have been materialized utilizing the Schikorr reaction following a facile approach and tested as mediators of heat for localized magnetic hyperthermia (MH) and as magnetic resonance imaging (MRI) agents. The synthetic protocol involves the interaction between two layered inorganic compounds, ferrous hydroxide, Fe(OH)2, and the synthetic smectite LAPONITE® clay Na0.7+[(Si8Mg5.5Li0.3)O20(OH)4]0.7-, towards the formation of superparamagnetic Fe3O4 nanoparticles, which are well decorated by the diamagnetic clay nanodisks. The latter imparts high negative ζ-potential values (up to -34.1 mV) to the particles, which provide stability against flocculation and precipitation, resulting in stable water dispersions. The obtained LAPONITE®-"decorated" Fe3O4 nanohybrids were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, dynamic light scattering (DLS) and vibrating sample magnetometry (VSM) at room temperature, revealing superior magnetic hyperthermia performance with specific absorption rate (SAR) values reaching 540 W gFe-1 (28 kA m-1, 150 kHz) for the hybrid material with a magnetic loading of 50 wt% Fe3O4/LAPONITE®. Toxicity studies were also performed with human glioblastoma (GBM) cells and human foreskin fibroblasts (HFF), which show negligible to no toxicity. Furthermore, T2-weighted MR imaging of rodent brain shows that the LAPONITE®-"decorated" Fe3O4 nanohybrids predominantly affected the transverse T2 relaxation time of tissue water, which resulted in a signal drop on the MRI T2-weighted imaging, allowing for imaging of the magnetic nanoparticles.

The effect of core size on the magnetic behavior of nanoparticle assemblies of gamma-Fe2O3 core/SiO2 shell morphology is investigated. Long-range magnetostatic interactions are probed in two highly monodispersed experimental test systems of spherical nanoparticles with core diameters of 10 nm and 12.5 nm, and a shell thickness varying from 0 nm (bare particles) to similar to 50 nm. Zero-Field-Cooled magnetization curves are calculated by employing the Monte Carlo simulation technique in a mesoscopic-scale model for the assembly, assuming spin collinearity and coherent spin-reversal mechanisms. Simulation results reproduce the trend in the behavior of the Zero-Field-Cooled magnetization versus T curves in good qualitative agreement with the experimental findings. They also demonstrate that the increase of the magnetic core size results in a shift of the maximum magnetization peak, T-max, to higher temperatures due to enhanced dipolar coupling. The results shed light on how interparticle distance and magnetic core size influence the value of T-max through collective behavior and its transition to a single-particle superparamagnetic blocking temperature, T-B, as the assembly becomes magnetically diluted with increasing shell thickness.

Pure g-C3N4 sample was prepared by thermal treatment of melamine at 520 °C, and iron-modified samples (0.1, 0.3 and 1.1 wt.%) were prepared by mixing g-C3N4 with iron nitrate and calcination at 520 °C. The photocatalytic activity of the prepared materials was investigated based on the photocatalytic reduction of CO2, which was conducted in a homemade batch reactor that had been irradiated from the top using a 365 nm Hg lamp. The photocatalyst with the lowest amount of iron ions exhibited an extraordinary methane and hydrogen evolution in comparison with the pure g-C3N4 and g-C3N4 with higher iron amounts. A higher amount of iron ions was not a beneficial for CO2 photoreduction because the iron ions consumed too many photogenerated electrons and generated hydroxyl radicals, which oxidized organic products from the CO2 reduction. It is clear that there are numerous reactions that occur simultaneously during the photocatalytic process, with several of them competing with CO2 reduction.

In this paper, we report a one-pot chemical synthesis technique for the preparation of iron and iron-carbide nanoparticles. Mössbauer spectroscopy, X-ray diffraction and magnetometry were used as the main tools to identify the different phases of Fe-C present. The influence of experimental parameters on the structural and compositional properties of nanoparticles was investigated in detail. These particles show ferromagnetic behavior with room temperature coercivity higher than 300 Oe. The X-ray diffraction was complemented by Mössbauer spectroscopy and thermo-magnetic analysis. Remarkably, the carbon content in iron-carbide nanoparticles (carbon rich or carbon poor iron-carbides) can be modulated simply by varying the experimental conditions, like the reaction time, temperature and iron precursor concentration. Magnetic properties can be tailored based upon crystallographic structure and particles composition.

Fe 16 N 2 is a compound with giant saturation magnetization approaching or exceeding that of rare‐earth‐based permanent magnets. The abundance of its elements and low‐cost synthesis of this compound has made it highly attractive to replace rare‐earth‐based permanent magnets that are becoming ever more expensive to utilize in applications. Herein, its synthesis from Fe flakes by surfactant‐assisted high energy ball milling is demonstrated. The synthesized Fe flakes are then reduced under forming gas (Ar/H 2 ), followed by nitridation at low temperatures under ammonia (NH 3 ) gas. The formation of Fe 16 N 2 phase exceeding 50% by volumetric fraction is observed and confirmed by X‐ray diffraction and Mössbauer analysis. Following the Fe 16 N 2 flake synthesis, extrusion‐based 3D printing is used to check the feasibility of incorporation of the flakes into functional polymer matrix composites. For this purpose, an ink of intermixed synthesized powder with photoresist SU8 is used. Using the prescribed method, a prototype Fe 16 N 2 permanent magnet composite is successfully produced using an additive manufacturing approach. Such efficient production of Fe 16 N 2 powders via routes already applicable to magnet production and the consolidation of the powders with 3D printing are expected to open up new possibilities for next‐generation permanent magnet applications.

Invited for the cover of this issue are Yann Garcia from Université catholique de Louvain, Belgium, and collaborators from partner universities and research centers. The cover image shows the square grid shape of an unprecedented Cu II coordination polymer with an “ancient temple architecture”.

Iron carbide nanoplatelets with an orthorhombic Fe3C structure were synthesized following a simple liquid chemical approach. The formation of the carbide phases was shown to depend on the presence of a long chain diol and the reaction temperature. Confirmation of the iron carbide phases and structural characterization was made by X-ray diffraction (XRD) and Mössbauer spectroscopy. Particle morphology was characterized by transmission electron microscopy (TEM) and HR-TEM and the magnetic properties were measured with magnetometry (VSM). The sample with the Fe3C phase shows a ferromagnetic behavior with a magnetization of 139 emu g-1 under a 30 kOe applied field. The simple methodology presented here for producing iron carbide nanoplatelets has promising application in the biomedical and catalyst industries.

A comparative study of dielectric, specific heat, and magnetic properties has been carried out between bulk Y3Fe5O12 (YIG) samples which display different behavior regarding the dielectric and ac-susceptibility spectra. Experimental results are presented from two categories of YIG samples (called sample-A and sample-B). Sample-A exhibits zero imaginary part chi '' (T) of the magnetic ac susceptibility whereas sample-B exhibits chi ''(T) curves with two well defined broad maxima in the kHz region. These two maxima can be assigned to two different relaxation regimes. The frequency dependence of real (epsilon') and imaginary (epsilon '') dielectric permittivity of sample-B reveals step-like transitions in E ' and local maxima in epsilon '' at the kHz region, which are indicative for several relaxation processes. These processes are not observed in the electric permittivity of sample-A, indicating that dielectric and magnetic relaxation effects depend strongly on the preparation conditions of YIG. Such a completely different spectral behavior among YIG samples corresponds to a direct shape change of absorption sextets in Mossbauer spectra (MS). It was discovered that samples without dispersion in magnetic susceptibility and electric permittivity exhibit MS with distinct broadening of absorption lines in tetrahedral sites, as compared with samples that display dispersion. Moreover, Mossbauer spectroscopy for both categories of samples does not provide evidence for the presence of Fe2+.

The Front Cover shows the structure of an unprecedented CuII coordination polymer, which resembles a two-dimensional square grid architecture. This compound acts as an excellent host for a pharmaceutically important bis(triazole) ligand, namely bis(1,2,4-triazole)-trans-cyclohexane. The self-assembly of this type of coordination polymers is affected by various kinetic and thermodynamic factors. More information can be found in the Full Paper by Y. Garcia et al. For more on the story behind the cover research, see the Cover Profile.

In this work, novel ternary catalysts Ag/TiO2/CoFe2O4 were synthesized with variable ferrite content for the photocatalytic reduction of Cr+6 pollutant, under UV and solar light illumination. Both TiO2 (T) and CoFe2O4 (CF) were synthesized using the sol-gel method followed by hydrothermal treatment to prepare the TiO2/CoFe2O4 (TCF) composite. Silver nanoparticles were successfully loaded on the surface of TCF to get different Ag/TCF composites. The analysis of their crystal structure indicated the presence of pure anatase phase TiO2, cubic CoFe2O4, and silver nanoparticles, in both XRD patterns and Raman spectra. It was found that the addition of silver nanoparticles to the titania/ferrite composite has a great contribution to the photocatalytic reduction of Cr+6 species. The photocatalytic reaction mechanism was studied by applying scavenging reaction process and spin trap experiments, revealing that photogenerated electrons were mainly responsible for the reduction of Cr+6 species. After the photocatalytic experiments, the composite catalyst can be easily separated from the reaction solution with a magnetic bar and be re-used.

L10 highly ordered FePt nanostructures were successfully synthesized following a direct one-step liquid phase chemical approach. The enhanced ordering was achieved with the use of bismuth additives in the reaction mixture. The as-made nanostructures are ferromagnetic, revealing high coercivity without any post annealing processing. The effect of bismuth addition was studied extensively, and the synthesized nanostructures were characterized by a plethora of techniques including TEM, STEM, elemental mapping, XRD, and Mössbauer spectroscopy for the structural and morphological characterization and VSM for the study of magnetic properties. The maximum room temperature coercivity of the directly synthesized FePt nanoalloys is 15.2 kOe, a value which is the highest, to the best of our knowledge, for analogous as-made liquid phase synthesized nanomaterials. The L10 FePt nanostructures with bismuth additives have promising applications in permanent magnets, in ultrahigh density recording media, and as highly durable Pt-based catalysis.

L1(0) highly ordered FePt nanostructures were successfully synthesized following a direct one-step liquid phase chemical approach. The enhanced ordering was achieved with the use of bismuth additives in the reaction mixture. The as-made nanostructures are ferromagnetic, revealing high coercivity without any post annealing processing. The effect of bismuth addition was studied extensively, and the synthesized nanostructures were characterized by a plethora of techniques including TEM, STEM, elemental mapping, XRD, and Mossbauer spectroscopy for the structural and morphological characterization and VSM for the study of magnetic properties. The maximum room temperature coercivity of the directly synthesized FePt nanoalloys is 15.2 kOe, a value which is the highest, to the best of our knowledge, for analogous as-made liquid phase synthesized nanomaterials. The L1(0) FePt nanostructures with bismuth additives have promising applications in permanent magnets, in ultrahigh density recording media, and as highly durable Pt-based catalysis.