Structural, magnetic, and electronic structure of the nanostructured (CoMn) 50 Ni 50 powders used in dye discoloration via a heterogeneous Fenton-like process (original) (raw)
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Magnetic and Electronic Structure Studies of Nanocrystalline (Co2Mn)40 Ni60 Alloy
Acta Physica Polonica A, 2021
Nanocrystalline (Co2Mn)40Ni60 (wt%) alloy powder was prepared by high-energy ball milling under an argon atmosphere. Structure, microstructure, and magnetic properties were investigated by means of X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The X-ray diffraction analysis indicates that after 30 h of milling, a highly disordered (Co, Mn, Ni) solid solution emerges, having an average crystallite size of around 60 nm and a lattice parameter of about 3.5411 Å. Magnetization-field curves indicate the existence of ferromagnetic behavior irrespective of the milling time with a low hysteresis loop, a typical characteristic of a soft magnetic material. The magnetic properties, however, are found to be sensitive to the milling time: i.e. the ratio Mr/Msat manifests the formation of multi-domains magnetic structure. Diverse magnetic parameters were acquired from the approach to magnetic saturation. The electronic structure of the ferromagnetic (Co2Mn)40Ni60 alloy performed by self-consistent ab initio calculations based on the Korringa-Kohn-Rostocker method combined with the coherent potential approximation, reveals that the total DOS is mainly due to the 3d-like states of the constituent elements Mn, Co and Ni.
Materials Research Express, 2019
Rare earth doped spinel ferrites belonging to the series Ni0.6Zn0.2Me0.2GdxFe2-xO4 (where Me = Mg/Mn, x = 0/0.06) were synthesized by sol-gel method. The characterizations of the prepared samples were performed using X-rayDiffraction (XRD), High Resolution Transmission Electron (HRTEM) Microscopy, Vibrating Sample Magnetometry (VSM), X-ray Photoelectron Spectroscopy (XPS) and Open aperture z-scan technique. The XRD patterns confirm the crystallization of the ferrites in cubic form with spinel structure. The average crystallite size calculated using Debye–Scherrer’s equation is in 10–20 nm range. The HRTEM images reveal the formation of spherically shaped agglomerated nanoparticles. The magnetic parameters such as remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms) were obtained from the hysteresis curves. The samples show better optical limiting parameters than reported which make them promising materials for non-linear applications requiring low limiting...
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In this study, the degradation efficiency of Mn-20at%Ni and Mn-30at%Ni particle powders made by melt-spinning and high-energy ball-milling techniques is investigated in relation to the degradation of the azo dye Reactive Black 5. SEM, EDS, and XRD were used to analyze the powders’ morphology, surface elemental composition, and phase structure. An ultraviolet-visible absorption spectrophotometer was used to measure the ball-milled powder’s capacity to degrade, and the collected powders were examined using the FTIR spectroscopy method to identify the substituents in the extract. The impact of MnNi alloy on the azo dye Reactive Black 5′s degradation and its effectiveness as a decolorizing agent were examined as functions of different parameters such as chemical composition, specific surface, and temperature. In comparison to the Mn-30at%Ni alloy, the powdered Mn-20at%Ni particles show better degrading efficiency and a faster rate of reaction. This remarkable efficiency is explained by ...
Structural and Magnetic Characterizations of Coprecipitated Ni–Zn and Mn–Zn Ferrite Nanoparticles
Magnetics, IEEE …, 2006
The reactions of [Mn III (L4a)Cl] or [Mn III (L4b)Cl] with [Pt(SCN) 6 ] 22 resulted in the formation of a 1D polymeric complex [{Mn(L4a)} 2 {m-Pt(SCN) 6 }] n (1) and a trinuclear compound [{Mn(L4b)(H 2 O)} 2 {m-Pt(SCN) 6 }] (2), where L4a and L4b are tetradentate dianionic Schiff base ligands, H 2 L4a = N,N9-ethylenebis(salicylimine) and H 2 L4b = N,N9-3-methylbenzenebis(3-ethoxysalicylimine). In compound 1, the adjacent [Mn(L4a)] + subunits are bound together through the phenolic oxygen atoms, thus forming [{Mn(L4a)} 2 ] 2+ dimers with the shortest Mn … Mn distance of 3.2101(5) Å, while in compound 2, the intermolecular bifurcated O-H … O hydrogen bonds between the neighbouring molecules form [{Mn(L4b)(H 2 O)} 2 ] 2+ dimers, resulting in a supramolecular 1D chain structure. The Mn … Mn distance within the supramolecular dimer is 4.7007(9) Å, while the shortest Mn … Mn distance between the dimers is 9.2347(10) Å. The magnetic analyses comprising the zero-field splitting resulted in a ferromagnetic exchange interaction within the phenolato-bridged dimer in 1 (J = +1.73 cm 21 , D Mn = 22.65 cm 21 ) and the antiferromagnetic exchange interaction within the supramolecular dimer in 2 (J = 20.88 cm 21 , D Mn = 23.06 cm 21 ). The experimental findings regarding the dominant as well as negligible exchange pathways are in good agreement with the results from DFT calculations at the B3LYP/TZVP level of theory. 634 954; Tel: +420 585 634 352 3 Electronic supplementary information (ESI) available: Fig. S1 (the correlation between the ferromagnetic exchange, J, and Mn-O* distance), Fig. S2 (modelling of the effect of ZFS on the magnetic properties of the dimer), Fig. S3 (the calculated spin density distribution using B3LYP/TZVP for [{Mn(L4b)(H 2 O)} 2 {m-Pt(SCN) 6 }] (2)) and Table S1 (the DFT calculated net Mulliken spin densities (r), the expectation values ,S 2 . and exchange energy (J) from the HS and BS states of the [{Mn(L4a)NCS} 2 ] and [{Mn(L4b)(H 2 O)(NCS)} 2 ] moieties extracted from the X-ray structures of 1 and 2, respectively), (the DFT calculated net Mulliken spin densities (r), the expectation values ,S 2 . and exchange energy (J) from the HS and BS states of [{Mn(L4b)(H 2 O)} 2 {m-Pt(SCN) 6 }] (2) based on a geometry from the X-ray structural determination). CCDC 930629 and 930630. For ESI and crystallographic data in CIF or other electronic format see
Journal of Nanoscience and Technology
To enhance the photocatalytic activity of TiO2 in visible light, nickel and manganese codoped TiO2 (NMTs) and undoped TiO2 nanomaterials were synthesized by varying dopant concentrations using a solgel method. As prepared nano materials were characterized by using X-ray diffraction (XRD) and its results shows anatase and rutile mixed phase was observed for codoped catalyst samples. Rough morphology, irregular particle shape and elemental composition of catalyst were identified with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) respectively. The Fourier transform infrared spectroscopy (FT-IR) result revealed that the substitutional doping of Mn 2+ and Ni 2+ into TiO2 lattice by replacing Ti 4+ in TiO2 lattice. This was confirmed by shifting of stretching frequencies of Ti-O-Ti from 569 cm-1-608 cm-1. The catalyst (NMT2) exhibits least band gap (2.7 eV), less particle size (6.5 nm) with high surface area (135.70 m 2 /g) when compared to undoped TiO2 (3.2 ev, 18.3 nm, 64.09 m 2 /g), which were determined by UV-visible diffused reflectance spectroscopy (UV Vis-DRS), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) respectively. Based on the characterization results the efficiency of codoped catalyst were exhibits better photocatalytic degradation of indigo caramine (IC). The results show that IC has degraded within 90 minutes at doping concentrations 1.0 wt% of Ni 2+ ion and 0.25 wt% of Mn 2+ ion in TiO2 (NMT2) at an optimum reaction parameter pH-3, catalyst dosage 0.080 g/L and at IC dye concentration of 0.020 g/L.
Magnetic properties and magnetocaloric effect at room temperature of Ni50−xAgxMn37Sn13 alloys
Journal of the Korean Physical Society, 2014
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Nickel ferrite nanoparticle as a magnetic catalyst: Synthesis and dye degradation
Proceedings of The 21st International Electronic Conference on Synthetic Organic Chemistry, 2017
The aim of this work is the synthesis of NiFe 2 O 4 nanoparticles to catalyze photodegradation of direct red 264 under visible light. So, NiFe 2 O 4 nanoparticles were synthesized by a sol-gel autocombustion method. The catalyst was characterized by XRD, SEM, FT-IR and DRS. The effect of NiFe 2 O 4 nanoparticles as a catalyst was studied on photocatalytic degradation of Direct Red 264 (DR264) in typical wastewater using visible light irradiation. UV-vis spectrophotometer was used to measure concentration of dyes before and after degradation.
Application of mechanically alloyed MnAl particles to de-colorization of azo dyes
Journal of Alloys and Compounds
The use of metallic particles has been shown to be an effective, low-cost method for degradation of many contaminating compounds. In this work, we analyze the efficiency of MnAl metallic powders for degrading azo dyes, which are the class of colorant compounds most utilized by the textile industry. We used different routes to produce the metallic particles obtaining different internal structures as characterized by X-ray diffraction and electronic microscopy. The ability to act as discoloration materials was assessed by decolorization experiments of Reactive Black 5 and Orange II azo dyes aqueous solutions. The degradation reaction of the dye molecules was monitored by ultraviolet-visible (UV) spectrophotometry showing fast kinetics, with reaction times among the shortest found in literature. The effect of the different production methods on their performance as decolorizing materials was studied as function as various parameters such as initial pH, dye concentration and temperature. The electrochemical and corrosion properties of the MnAl compounds seem to be the key factors explaining the high decolorization efficiency of these materials. *Manuscript-revised Click here to view linked References
Chemical Synthesis and Characterization of a Nanometric Fe 50 Ni 50 Alloy
Materials Science Forum, 2002
Growing interest in the synthesis of palladium oxide arises from its potential use as a palladium precursor, for catalysis and as an electrode material. We report the preparation of palladium oxide by precipitation from supersaturated aqueous solutions of Pd(N03) 2 or PdCI 2. Theoretical modeling was carried out to ascertain the best yield of the reaction with respect to the preparation conditions, i.e. temperature, pH and ionic strength, in the PdO-HCI-NH3-tlNO3-NaOH-H20 system. Experiments were performed in a batch reactor, and effects of the various parameters such as the reagent flow-rates or the aging time were studied Microstructurai characterization of the resulting powders shows that only hydrated palladium oxide PdO.xH20 is formed, with structural features ranging from polymeric entities undetectable by Photon Correlation Spectroscopy to porous aggregates containing 20 nm sized primary particles with varying degree of crystallinily. Reduction of the palladium oxide in ethanol to produce metallic palladium is also briefly discussed