Wyniki wyszukiwania - BazTech

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Aegle marmelos leaf extract based synthesis of nanoiron and nanoiron+Au particles for degradation of methylene blue

Tarangini Korumilli, Jagajjanani Rao K., Wacławek Stanisław, Černík Miroslav, Padil Vinod V. T.

Ecological Chemistry and Engineering. S

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2022

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Vol. 29, nr 1

7--14

EN

In this study, nanoiron and nanoiron+Au particles were synthesised using aqueous Aegle marmelos extract using a facile and one-pot approach. Lower size non-magnetic nanoiron (~34 nm) and nanoiron (~34 nm)+Au particles (1 to 1.5 μm) were produced from the same medium individually. Nanoparticles suspension behaviour and structural characterisations were carried out by UV-Vis spectroscopy, electron microscopy and by X-ray diffraction techniques. Primarily, for synthesis, a simple bioreduction approach generated amorphous nanoiron particles, which on annealing produced magnetic maghemite, γ-Fe2O3 type nanoparticles with sizes 100 to 1000 nm. Posteriorly, the bioreduction process also produces nanoiron+Au particles and can be used for multifunctional applications. As a model application, catalytic application of the as-prepared nanoiron and nanoiron+Au particles towards methylene blue, a thiazine dye degradation is investigated and found to be effective within 20 min. Langmuir-Hinshelwood kinetic model was exploited to know the degradation behaviour, and the model was found to be fit based on R2 values with the observed experimental data. We suggest that the formed highly stable nanoiron particles with in situ stabilisation offer benefits like consistency, environmental friendliness and suits well for large-scale applicability.

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Application of magnetic nanoparticles for water treatment

Marcinkowska D.

Technical Issues

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2016

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nr 2

33--38

EN

In this study magnetic nanoparticles were fabricated and used for water treatment. Nanoparticles were prepared in two ways. The first one involved NiZn ferrite nanoparticles synthesized by co-precipitation of metal cations with sodium hydroxide at high temperature. The second one featured maghemite nanoparticles was prepared by salt-assisted solid-state reaction. Modification and functionalization of nanoparticles surface was investigated. Nanoparticles were characterized by scanning electron microscopy (SEM). Modified nanoparticles were added to the solution of desired concentration of methylene green. Adsorption ability was examined trough ultraviolet-visible spectroscopy (UV-VIS). For NiZn ferrite and also for maghemite nanoparticles results were positive. Both of complexes can be used for water treatment with 51% success for maghemite and 72% for NiZn ferrite nanoparticles.

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Transformation mechanism of magnetite nanoparticles

Khan U. S., Amanullah, Manan A., Khan N., Mahmood A., Rahim A.

Materials Science Poland

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2015

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Vol. 33, No. 2

278--285

EN

A simple oxidation synthesis route was developed for producing magnetite nanoparticles with controlled size and morphology. Investigation of oxidation process of the produced magnetite nanoparticles (NP) was performed after synthesis under different temperatures. The phase transformation of synthetic magnetite nanoparticles into maghemite and, henceforth, to hematite nanoparticles at different temperatures under dry oxidation has been studied. The natural magnetite particles were directly transformed to hematite particles at comparatively lower temperature, thus, maghemite phase was bypassed. The phase structures, morphologies and particle sizes of the produced magnetic nanoparticles have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and BET surface area analysis.

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Synthesis of maghemite (γ-Fe2O3) nanoparticles by thermal-decomposition of magnetite (Fe3O4) nanoparticles

Aliahmad M., Nasari-Moghaddam M.

Materials Science Poland

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2013

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Vol. 31, No. 2

264--268

EN

In this research work, we prepared g-Fe2O3 nanoparticles by thermal-decomposition of Fe3O4. The Fe3O4 nanoparticles were synthesized via co-precipitation method at room temperature. This simple, soft and cheap method is suitable for preparation of iron oxide nanoparticles (g-Fe2O3; Fe3O4). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer and differential scanning calorimeter (DSC). The XRD and FT-IR results indicated the formation of g-Fe2O3 and Fe3O4 nanoparticles. The TEM images showed that the g-Fe2O3 and Fe3O4 were spherical, and their size was 18 and 22 nm respectively. Magnetic properties have been measured by VSM at room temperature. Hysteresis loops showed that the g-Fe2O3 and Fe3O4 nanoparticles were super-paramagnetic.