TY  - JOUR
AU  - Popov, Nina
AU  - Ristić, Mira
AU  - Bošković, Marko
AU  - Perović, Marija M.
AU  - Musić, Svetozar
AU  - Stanković, Dalibor M.
AU  - Krehula, Stjepko
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9929
AB  - Sn-doped hematite (α-Fe2O3) nanoparticles of fairly uniform and Sn-dependent size and shape were synthesized via a simple combination of hydrothermal co-precipitation and calcination. The effects of Sn doping on the unit cell size, crystallinity, particle size and shape, as well as the magnetic, optical and photocatalytic properties of hematite nanoparticles were analyzed. The incorporation of Sn4+ ions into the crystal structure of hematite was confirmed by determination of the unit cell expansion due to the replacement of octahedrally coordinated Fe3+ ions by significantly larger Sn4+ ions, as well as a substantially reduced hyperfine magnetic field due to magnetic dilution upon the substitution of non-magnetic Sn4+ ions for magnetic high-spin Fe3+ ions. Sn doping caused a decrease in length and width and an increase in thickness of elongated hematite nanoparticles. Fairly uniform Sn-doped hematite nanoellipsoids or nanocuboids were formed, depending on the Sn content. Temperature dependence of magnetization measurements showed the disappearance of the magnetic phase transition (Morin transition) in hematite upon Sn doping. Magnetic coercivity decreased upon Sn doping due to a decrease in shape anisotropy induced by the change in particle shape from nanorods to nanoellipsoids and nanocuboids. The optical and electronic properties of hematite nanoparticles were significantly affected by Sn doping – the absorption edge was shifted to higher wavelengths, while direct and indirect optical band gaps narrowed with the increasing Sn4+-for-Fe3+ substitution. Sn-doped hematite nanoellipsoids containing 4.3 mol% Sn exhibited a substantial visible light photocatalytic activity in the heterogeneous photo-Fenton process, but this activity significantly decreased with higher Sn doping.
T2  - Journal of Physics and Chemistry of Solids
T1  - Influence of Sn doping on the structural, magnetic, optical and photocatalytic properties of hematite (α-Fe2O3) nanoparticles
VL  - 161
SP  - 110372
DO  - 10.1016/j.jpcs.2021.110372
ER  - 

@article{
author = "Popov, Nina and Ristić, Mira and Bošković, Marko and Perović, Marija M. and Musić, Svetozar and Stanković, Dalibor M. and Krehula, Stjepko",
year = "2022",
abstract = "Sn-doped hematite (α-Fe2O3) nanoparticles of fairly uniform and Sn-dependent size and shape were synthesized via a simple combination of hydrothermal co-precipitation and calcination. The effects of Sn doping on the unit cell size, crystallinity, particle size and shape, as well as the magnetic, optical and photocatalytic properties of hematite nanoparticles were analyzed. The incorporation of Sn4+ ions into the crystal structure of hematite was confirmed by determination of the unit cell expansion due to the replacement of octahedrally coordinated Fe3+ ions by significantly larger Sn4+ ions, as well as a substantially reduced hyperfine magnetic field due to magnetic dilution upon the substitution of non-magnetic Sn4+ ions for magnetic high-spin Fe3+ ions. Sn doping caused a decrease in length and width and an increase in thickness of elongated hematite nanoparticles. Fairly uniform Sn-doped hematite nanoellipsoids or nanocuboids were formed, depending on the Sn content. Temperature dependence of magnetization measurements showed the disappearance of the magnetic phase transition (Morin transition) in hematite upon Sn doping. Magnetic coercivity decreased upon Sn doping due to a decrease in shape anisotropy induced by the change in particle shape from nanorods to nanoellipsoids and nanocuboids. The optical and electronic properties of hematite nanoparticles were significantly affected by Sn doping – the absorption edge was shifted to higher wavelengths, while direct and indirect optical band gaps narrowed with the increasing Sn4+-for-Fe3+ substitution. Sn-doped hematite nanoellipsoids containing 4.3 mol% Sn exhibited a substantial visible light photocatalytic activity in the heterogeneous photo-Fenton process, but this activity significantly decreased with higher Sn doping.",
journal = "Journal of Physics and Chemistry of Solids",
title = "Influence of Sn doping on the structural, magnetic, optical and photocatalytic properties of hematite (α-Fe2O3) nanoparticles",
volume = "161",
pages = "110372",
doi = "10.1016/j.jpcs.2021.110372"
}

Popov, N., Ristić, M., Bošković, M., Perović, M. M., Musić, S., Stanković, D. M.,& Krehula, S.. (2022). Influence of Sn doping on the structural, magnetic, optical and photocatalytic properties of hematite (α-Fe2O3) nanoparticles. in Journal of Physics and Chemistry of Solids, 161, 110372.
https://doi.org/10.1016/j.jpcs.2021.110372

Popov N, Ristić M, Bošković M, Perović MM, Musić S, Stanković DM, Krehula S. Influence of Sn doping on the structural, magnetic, optical and photocatalytic properties of hematite (α-Fe2O3) nanoparticles. in Journal of Physics and Chemistry of Solids. 2022;161:110372.
doi:10.1016/j.jpcs.2021.110372 .

Popov, Nina, Ristić, Mira, Bošković, Marko, Perović, Marija M., Musić, Svetozar, Stanković, Dalibor M., Krehula, Stjepko, "Influence of Sn doping on the structural, magnetic, optical and photocatalytic properties of hematite (α-Fe2O3) nanoparticles" in Journal of Physics and Chemistry of Solids, 161 (2022):110372,
https://doi.org/10.1016/j.jpcs.2021.110372 . .

TY  - JOUR
AU  - Popov, Nina
AU  - Krehula, Stjepko
AU  - Ristić, Mira
AU  - Kuzmann, Erno
AU  - Homonnay, Zoltan
AU  - Bošković, Marko
AU  - Stanković, Dalibor M.
AU  - Kubuki, Shiro
AU  - Musić, Svetozar
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9619
AB  - Pure and Cr-doped hematite (α-(Fe1-xCrx)2O3, x = 0, 0.026, 0.039, 0.085 or 0.135) nanorods were prepared by a simple co-precipitation and calcination method. Influence of different levels of Cr doping on the change of properties of long and thin pure hematite nanorods was investigated. Cr3+-for-Fe3+ substitution in the crystal structure of hematite was proved by measuring a gradual contraction of the unit cell and a gradual decrease of the hyperfine magnetic field by increasing the Cr molar fraction. Cr doping induced an increase in the width and thickness of hematite nanorods, as well as a decrease in the overall surface area. Low temperature 57Fe Mössbauer spectroscopy showed that the Morin transition in hematite was suppressed by Cr doping to temperatures below 80 K. Magnetic measurements confirmed the suppression of the Morin transition in Cr-doped hematite down to 5 K. Infrared spectra of Cr-doped hematite samples showed shifts of IR bands by Cr3+-for-Fe3+ substitution. Optical properties of α-Fe2O3 nanorods changed significantly by Cr doping – the absorption edge was shifted to higher wavelengths, accompanied by a greater absorption in the visible range and narrowed direct and indirect optical band gaps. The improved visible light photocatalytic activity of hematite nanorods in the heterogeneous photo-Fenton process by moderate Cr doping was measured, which can be attributed to the modifications in electronic structure and optical properties. © 2020 Elsevier Ltd
T2  - Journal of Physics and Chemistry of Solids
T1  - Influence of Cr doping on the structural, magnetic, optical and photocatalytic properties of α-Fe2O3 nanorods
VL  - 148
DO  - 10.1016/j.jpcs.2020.109699
ER  - 

@article{
author = "Popov, Nina and Krehula, Stjepko and Ristić, Mira and Kuzmann, Erno and Homonnay, Zoltan and Bošković, Marko and Stanković, Dalibor M. and Kubuki, Shiro and Musić, Svetozar",
year = "2021",
abstract = "Pure and Cr-doped hematite (α-(Fe1-xCrx)2O3, x = 0, 0.026, 0.039, 0.085 or 0.135) nanorods were prepared by a simple co-precipitation and calcination method. Influence of different levels of Cr doping on the change of properties of long and thin pure hematite nanorods was investigated. Cr3+-for-Fe3+ substitution in the crystal structure of hematite was proved by measuring a gradual contraction of the unit cell and a gradual decrease of the hyperfine magnetic field by increasing the Cr molar fraction. Cr doping induced an increase in the width and thickness of hematite nanorods, as well as a decrease in the overall surface area. Low temperature 57Fe Mössbauer spectroscopy showed that the Morin transition in hematite was suppressed by Cr doping to temperatures below 80 K. Magnetic measurements confirmed the suppression of the Morin transition in Cr-doped hematite down to 5 K. Infrared spectra of Cr-doped hematite samples showed shifts of IR bands by Cr3+-for-Fe3+ substitution. Optical properties of α-Fe2O3 nanorods changed significantly by Cr doping – the absorption edge was shifted to higher wavelengths, accompanied by a greater absorption in the visible range and narrowed direct and indirect optical band gaps. The improved visible light photocatalytic activity of hematite nanorods in the heterogeneous photo-Fenton process by moderate Cr doping was measured, which can be attributed to the modifications in electronic structure and optical properties. © 2020 Elsevier Ltd",
journal = "Journal of Physics and Chemistry of Solids",
title = "Influence of Cr doping on the structural, magnetic, optical and photocatalytic properties of α-Fe2O3 nanorods",
volume = "148",
doi = "10.1016/j.jpcs.2020.109699"
}

Popov, N., Krehula, S., Ristić, M., Kuzmann, E., Homonnay, Z., Bošković, M., Stanković, D. M., Kubuki, S.,& Musić, S.. (2021). Influence of Cr doping on the structural, magnetic, optical and photocatalytic properties of α-Fe2O3 nanorods. in Journal of Physics and Chemistry of Solids, 148.
https://doi.org/10.1016/j.jpcs.2020.109699

Popov N, Krehula S, Ristić M, Kuzmann E, Homonnay Z, Bošković M, Stanković DM, Kubuki S, Musić S. Influence of Cr doping on the structural, magnetic, optical and photocatalytic properties of α-Fe2O3 nanorods. in Journal of Physics and Chemistry of Solids. 2021;148.
doi:10.1016/j.jpcs.2020.109699 .

Popov, Nina, Krehula, Stjepko, Ristić, Mira, Kuzmann, Erno, Homonnay, Zoltan, Bošković, Marko, Stanković, Dalibor M., Kubuki, Shiro, Musić, Svetozar, "Influence of Cr doping on the structural, magnetic, optical and photocatalytic properties of α-Fe2O3 nanorods" in Journal of Physics and Chemistry of Solids, 148 (2021),
https://doi.org/10.1016/j.jpcs.2020.109699 . .

TY  - JOUR
AU  - Popov, Nina
AU  - Bošković, Marko
AU  - Perović, Marija M.
AU  - Németh, Zoltán
AU  - Wang, Junhu
AU  - Kuang, Zhichong
AU  - Reissner, Michael
AU  - Kuzmann, Ernő
AU  - Homonnay, Zoltán
AU  - Kubuki, Shiro
AU  - Marciuš, Marijan
AU  - Ristić, Mira
AU  - Musić, Svetozar
AU  - Stanković, Dalibor M.
AU  - Krehula, Stjepko
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9516
AB  - Pure hematite nanorods and very long and thin cobalt-doped hematite nanorods (nanoneedles) were prepared by a combined precipitation and annealing method. The influence of the level of cobalt doping on different properties of hematite nanorods was investigated. Incorporation of cobalt in the form of low-spin Co3+ ions into the structure of hematite by substitution for high-spin Fe3+ ions was proved by determination of a significant unit cell contraction by powder X-ray diffraction (PXRD) and characteristic positions of the absorption edge in X-ray absorption near edge structure (XANES) spectra and peaks in X-ray emission (XES) spectra. Cobalt doping caused a gradual elongation and thinning of hematite nanorods – very long and thin 1D nanoparticles (nanoneedles) were formed in the presence of 10 and 12 mol% Co. Magnetic measurements showed a strong increase in low-temperature remanent magnetization and coercivity upon cobalt doping, as well as a disappearance of the Morin transition, which was also confirmed by Mössbauer spectroscopy. Cobalt doping significantly affected optical properties of hematite nanorods – absorption in the visible and NIR ranges increased, which was accompanied by narrowing of the optical band gap. Compared with pure hematite nanorods cobalt-doped hematite nanoneedles showed a significantly better electrocatalytic activity for the oxygen evolution reaction (OER). © 2020 Elsevier Ltd
T2  - Journal of Physics and Chemistry of Solids
T1  - Influence of low-spin Co3+ for high-spin Fe3+ substitution on the structural, magnetic, optical and catalytic properties of hematite (α-Fe2O3) nanorods
VL  - 152
SP  - 109929
DO  - 10.1016/j.jpcs.2020.109929
ER  - 

@article{
author = "Popov, Nina and Bošković, Marko and Perović, Marija M. and Németh, Zoltán and Wang, Junhu and Kuang, Zhichong and Reissner, Michael and Kuzmann, Ernő and Homonnay, Zoltán and Kubuki, Shiro and Marciuš, Marijan and Ristić, Mira and Musić, Svetozar and Stanković, Dalibor M. and Krehula, Stjepko",
year = "2021",
abstract = "Pure hematite nanorods and very long and thin cobalt-doped hematite nanorods (nanoneedles) were prepared by a combined precipitation and annealing method. The influence of the level of cobalt doping on different properties of hematite nanorods was investigated. Incorporation of cobalt in the form of low-spin Co3+ ions into the structure of hematite by substitution for high-spin Fe3+ ions was proved by determination of a significant unit cell contraction by powder X-ray diffraction (PXRD) and characteristic positions of the absorption edge in X-ray absorption near edge structure (XANES) spectra and peaks in X-ray emission (XES) spectra. Cobalt doping caused a gradual elongation and thinning of hematite nanorods – very long and thin 1D nanoparticles (nanoneedles) were formed in the presence of 10 and 12 mol% Co. Magnetic measurements showed a strong increase in low-temperature remanent magnetization and coercivity upon cobalt doping, as well as a disappearance of the Morin transition, which was also confirmed by Mössbauer spectroscopy. Cobalt doping significantly affected optical properties of hematite nanorods – absorption in the visible and NIR ranges increased, which was accompanied by narrowing of the optical band gap. Compared with pure hematite nanorods cobalt-doped hematite nanoneedles showed a significantly better electrocatalytic activity for the oxygen evolution reaction (OER). © 2020 Elsevier Ltd",
journal = "Journal of Physics and Chemistry of Solids",
title = "Influence of low-spin Co3+ for high-spin Fe3+ substitution on the structural, magnetic, optical and catalytic properties of hematite (α-Fe2O3) nanorods",
volume = "152",
pages = "109929",
doi = "10.1016/j.jpcs.2020.109929"
}

Popov, N., Bošković, M., Perović, M. M., Németh, Z., Wang, J., Kuang, Z., Reissner, M., Kuzmann, E., Homonnay, Z., Kubuki, S., Marciuš, M., Ristić, M., Musić, S., Stanković, D. M.,& Krehula, S.. (2021). Influence of low-spin Co3+ for high-spin Fe3+ substitution on the structural, magnetic, optical and catalytic properties of hematite (α-Fe2O3) nanorods. in Journal of Physics and Chemistry of Solids, 152, 109929.
https://doi.org/10.1016/j.jpcs.2020.109929

Popov N, Bošković M, Perović MM, Németh Z, Wang J, Kuang Z, Reissner M, Kuzmann E, Homonnay Z, Kubuki S, Marciuš M, Ristić M, Musić S, Stanković DM, Krehula S. Influence of low-spin Co3+ for high-spin Fe3+ substitution on the structural, magnetic, optical and catalytic properties of hematite (α-Fe2O3) nanorods. in Journal of Physics and Chemistry of Solids. 2021;152:109929.
doi:10.1016/j.jpcs.2020.109929 .

Popov, Nina, Bošković, Marko, Perović, Marija M., Németh, Zoltán, Wang, Junhu, Kuang, Zhichong, Reissner, Michael, Kuzmann, Ernő, Homonnay, Zoltán, Kubuki, Shiro, Marciuš, Marijan, Ristić, Mira, Musić, Svetozar, Stanković, Dalibor M., Krehula, Stjepko, "Influence of low-spin Co3+ for high-spin Fe3+ substitution on the structural, magnetic, optical and catalytic properties of hematite (α-Fe2O3) nanorods" in Journal of Physics and Chemistry of Solids, 152 (2021):109929,
https://doi.org/10.1016/j.jpcs.2020.109929 . .