Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• ][132]. The incorporation of various types of NPs using neat clay and applying a two-step synthesis has been reported. A recent example of this refers to the incorporation of ZnO nanoparticles to a Fe3O4-sepiolite nanoarchitecture previously prepared by in situ formation of superparamagnetic iron-oxide

• nanoparticles on the external surface of sepiolite fibres. The resulting ZnO–Fe3O4@sepiolite nanoarchitecture exhibits photoactivity due to the ZnO NPs, and the presence of magnetite NPs facilitates the recovery by the use of a magnet (Figure 4) [133]. Moreover, the presence of iron oxide could be useful also

• isopropoxide; reprinted with permission from [109], copyright 2008 American Chemical Society. ZnO-Fe3O4@sepiolite nanoarchitecture prepared in two steps: First, the fiber clay is modified by assembly of magnetite NPs. After that, the ZnO NPs are added yielding a magnetic photocatalyst. The STEM images on the

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

• Małgorzata Świętek,
• Yi-Chin Lu,
• Rafał Konefał,
• Liliana P. Ferreira,
• M. Margarida Cruz,
• Yunn-Hwa Ma and
• Daniel Horák

Beilstein J. Nanotechnol. 2019, 10, 1073–1088, doi:10.3762/bjnano.10.108

• functional groups. In this study, magnetite (Fe3O4) nanoparticles were synthetized by coprecipitation of iron(II) chloride and iron(III) chloride with ammonia and subsequently oxidized with hydrogen peroxide under mild acidic conditions. The resulting maghemite (γ-Fe2O3) has the benefit of higher chemical

• stability over Fe3O4 due to the lack of iron(II) atoms that are prone to oxidation [24]. TEM micrographs of the γ-Fe2O3 particles showed their quasi-spherical shape and a moderately broad size distribution (Figure 2a). The dispersity of the particles (Ð) was 1.25, and the number-average particle diameter

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• 710119, China Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha and 410083, China 10.3762/bjnano.10.107 Abstract Fe3O4 nanoparticles (FONPs) are magnetic materials with a small band gap and have well-demonstrated

• , and optical modulators. Keywords: erbium laser; Fe3O4 nanoparticles; fiber lasers; saturable absorber; Introduction Fe3O4 nanoparticles (FONPs) are excellent magnetic materials, which allows for many applications in various fields such as medical transmission, microwave devices, and optical devices

• . In addition, FONPs also exhibit nonlinear photonic properties such as two-photon absorption, nonlinear scattering, and optical confinement [1][2]. Ferrous ferric oxide (Fe3O4) is a transition metal oxide that has a large third-order nonlinear optical susceptibility of χ(3) = 4.0 × 10−10 esu and an

Synthesis of MnO₂–CuO–Fe₂O₃/CNTs catalysts: low-temperature SCR activity and formation mechanism

• Yanbing Zhang,
• Lihua Liu,
• Yingzan Chen,
• Xianglong Cheng,
• Chengjian Song,
• Mingjie Ding and
• Haipeng Zhao

Beilstein J. Nanotechnol. 2019, 10, 848–855, doi:10.3762/bjnano.10.85

• ) of the Mn–Cu–FeOx/CNTs-IWIM catalyst appear at lower energies than those of 4% MnO2–CuO–Fe2O3/CNTs catalyst, revealing the formation of Fe3O4 [35]. Moreover, the absence of any satellites further proved the presence of Fe3O4. It is noteworthy that Fe2O3 exhibits a better low-temperature SCR activity

• than Fe3O4 [36], which is corroborated by the NO conversion measurements. The O 1s peak can be divided into three peaks (Figure 4F). The peak at 529.9 eV is attributed to lattice oxygen (designated as OL), while the binding energies at 530.5–534.0 eV are ascribed to surface oxygen (labeled as OS). The

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• . Then, a concentrated (24 wt %) NH4OH solution (750 µL) was added, resulting in the immediate formation of a black precipitate of magnetite (Fe3O4) nanoparticles. Sonication was continued for an additional 10 min. The liquid was decanted with the help of magnetic separation, using a 0.5 T magnet. The

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

• Boris N. Khlebtsov,
• Andrey M. Burov,
• Timofey E. Pylaev and
• Nikolai G. Khlebtsov

Beilstein J. Nanotechnol. 2019, 10, 794–803, doi:10.3762/bjnano.10.79

• ], Fe3O4 [35], graphene [36], and many others [37][38]. The PDA shell surface contains numerous catechol and quinone groups suitable for click conjugation with various biomolecules through Michael addition and Schiff-base reaction [39][40]. The high loading capacity and biocompatibility of the PDA layer

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances

• Kun Ren,
• Xiaobin Ren,
• Yumeng He and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 247–255, doi:10.3762/bjnano.10.23

• field. It depends on the type of carrier liquid and the concentration of the magnetic fluid. nsat is the saturation value of the refractive index. In this paper, the magnetic fluid is a colloidal solution consisting of Fe3O4 nanoparticles dispersed in water with n0 = 1.4612. The concentration of the

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• , 117997, Russia Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen (CENIDE), Duisburg, 47057, Germany D. Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russia 10.3762/bjnano.9.251 Abstract Size-selected Fe3O4–Au hybrid nanoparticles with

• diameters of 6–44 nm (Fe3O4) and 3–11 nm (Au) were prepared by high temperature, wet chemical synthesis. High-quality Fe3O4 nanocrystals with bulk-like magnetic behavior were obtained as confirmed by the presence of the Verwey transition. The 25 nm diameter Fe3O4–Au hybrid nanomaterial sample (in aqueous

• exposure and after precultivation of the cells for 6 h with 25 nm Fe3O4–Au hybrid nanomaterials, respectively. This confirms that the improved magnetic properties of the bifunctional particles present a next step in magnetic-particle-based theranostics. Keywords: hybrid nanoparticles; magnetic

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• magnetic field. As a result, magnetic nanomaterials have drawn increasing attention. Nanocellulose incorporated with other magnetic nanomaterials is presented as an excellent composite adsorbent with magnetic properties. For example, a core–shell cellulose magnetite (Fe3O4) polymeric ionic liquid magnetic

• increase its aromatic character, anion exchange capability, and hydrophilic nature of cellulose. Cellulose could also act as a stabilizer for the Fe3O4 nanoparticles to prevent crystal growth and aggregation of particles. In general, magnetic iron oxide is anchored in the polymer matrix to induce magnetic

• properties in nanocomposites such as Fe3O4@SiO2@cellulose nanocomposite and amino-functionalized magnetic cellulose nanocomposite grafted with glycidyl methacrylate followed by reaction with ethylenediamine [89]. Furthermore, a 7 wt % NaOH/12 wt % urea aqueous solvent was found useful for regenerating Cr(VI

Droplet-based synthesis of homogeneous magnetic iron oxide nanoparticles

• Christian D. Ahrberg,
• Ji Wook Choi and
• Bong Geun Chung

Beilstein J. Nanotechnol. 2018, 9, 2413–2420, doi:10.3762/bjnano.9.226

• ). To confirm the elemental composition of the nanoparticles energy-dispersive X-ray spectroscopy (EDS) was conducted after TEM imaging (Figure S2A,B in Supporting Information File 1), confirming that the particles consisted of Fe3O4. Moreover, the electron diffraction patterns were analyzed (Figure S2C

• ,D in Supporting Information File 1), finding the same spinel crystalline planes as previously reported in literature for Fe3O4 nanopowders [32]. Hence, the synthesized particles are crystalline. Regarding the yield of the reaction both synthesis delivered comparable nanoparticle yields after washing

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• .9.185 Abstract Heterogeneous Fenton-like catalysts with the activation of peroxymonosulfate (PMS), which offer the advantages of fast reaction rate, wide functional pH range and cost efficiency, have attracted great interest in wastewater treatment. In this study, a novel magnetic MnO2/Fe3O4/diatomite

• nanocomposite is synthesized and then used as heterogeneous Fenton-like catalyst to degrade the organic pollutant methylene blue (MB) with the activation of PMS. The characterization results show that the Fe3O4 nanoparticles and nanoflower-like MnO2 are evenly distributed layer-by-layer on the surface of

• mineralization rate of about 60% in 60 min and great recyclability with a recycle efficiency of 86.78% after five runs for MB. The probable mechanism of this catalytic system is also proposed as a synergistic effect between MnO2 and Fe3O4. Keywords: diatomite; Fenton-like oxidation; hybrid catalyst; iron(II,III

Magnetic properties of Fe₃O₄ antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

• Juan L. Palma,
• Alejandro Pereira,
• Raquel Álvaro,
• José Miguel García-Martín and
• Juan Escrig

Beilstein J. Nanotechnol. 2018, 9, 1728–1734, doi:10.3762/bjnano.9.164

• .9.164 Abstract Magnetic films of magnetite (Fe3O4) with controlled defects, so-called antidot arrays, were synthesized by a new technique called AFIR. AFIR consists of the deposition of a thin film by atomic layer deposition, the generation of square and hexagonal arrays of holes using focused ion beam

• other techniques. As a proof of concept, we will investigate the magnetic properties of Fe3O4 antidot arrays that have never been fabricated until now. As magnetic antidots have been successfully used to preferentially capture magnetic nanoparticles within the holes [36], and as Fe3O4 is a biocompatible

• material, such new Fe3O4 antidot arrays are of interest for the future development of nano-scale biosensors. Experimental Figure 1 shows the outline of the AFIR process. Si(100) wafers with a native layer of SiO2 were coated with hematite (Fe2O3) in a Savannah S100 ALD reactor from Ultratech operated at

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• with further increase in the calcination temperature because of the decrease in the specific surface area induced by the aggregation and agglomeration of particles [157]. TiO2/Fe3O4 composite photocatalysts were synthesized through a polymerizable sol−gel route to investigate the photocatalytic

• reduction of Cr(VI) under UV light irradiation. The anchoring of TiO2 over Fe3O4 resulted in (i) high dispersion of the active site, which is important for achieving higher reaction rate, (ii) enhancement of the photoreduction rate by decreasing the recombination of electron−hole pairs due to significant

• overlap of the TiO2 band with that of Fe3O4 and (iii) efficient separation and recyclability of the catalyst under application of an external magnetic field because of the presence of magnetic Fe3O4. Therefore, the composite photocatalysts exhibited a higher rate of photoreduction of Cr(VI) as compared to

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• analysis of uncoated SPIOs (Fe3O4). ImageJ software (NIH, Bethesda, MD) was used to measure the mean diameter of the particles from TEM images. Scanning electron microscopy Uncoated SPIOs, PEG-SPIOs, and IPC-SPIOs were characterized by field-emission scanning electron microscopy (FE-SEM, Supra 55 VP, Carl

• uncoated SPIOs (Fe3O4) (C). SEM images of uncoated SPIOs (D), PEG-SPIOs (E), and IPC-SPIOs with PEG and polygallol (F). PEG-SPIOs (n = 66) and uncoated SPIOs (n = 25) were measured to calculate the mean size of the particles and PEG coating thickness in the TEM images, respectively. Microscopy images of

Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

• Nor Fazila Khairudin,
• Mohd Farid Fahmi Sukri,
• Mehrnoush Khavarian and
• Abdul Rahman Mohamed

Beilstein J. Nanotechnol. 2018, 9, 1162–1183, doi:10.3762/bjnano.9.108

• to form iron oxide (Fe3O4). Next, the lattice oxygen (OL) obtained from the reduction of Fe3O4 was pooled with carbon deposited on the metal (Cm) to form CO. However, carbon located far from the active sites (Cs) does not directly intermingle with CO2. Based on the results of this study, the

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• ]. Generally, biocompatible magnetite (Fe3O4), iron oxide, iron sulfides and maghemite (Fe2O3) are synthesized using magnetotactic bacteria [156][157] that helps in targeted cancer treatment via magnetic hyperthermia, magnetic resonance imaging (MRI), DNA analysis and gene therapy [158]. Moreover, surface

Enzymatically promoted release of organic molecules linked to magnetic nanoparticles

• Chiara Lambruschini,
• Silvia Villa,
• Luca Banfi,
• Fabio Canepa,
• Fabio Morana,
• Annalisa Relini,
• Paola Riani,
• Renata Riva and
• Fulvio Silvetti

Beilstein J. Nanotechnol. 2018, 9, 986–999, doi:10.3762/bjnano.9.92

• to the loss of material during the workup and purification. Preliminary experiments of conjugation with Fe3O4 nanoparticles functionalized with 3-aminopropyltriethoxysilane (APTES) showed that the purification of 6 was essential. In fact, the presence of excess PhSiH3 and the residues of Pd were

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• organic cells. Because of these toxic properties the films and nanostructures of such metals or metal compounds are widely used as antibacterial and antimicrobial agents. Among them are Ag, Cu, Au, CuO, ZnO, Fe3O4, Al2O3 and TiO2, to name just a few [1][2][3]. They all exhibit bactericidal properties

Heavy-metal detectors based on modified ferrite nanoparticles

• Urszula Klekotka,
• Ewelina Wińska,
• Elżbieta Zambrzycka-Szelewa,
• Dariusz Satuła and
• Beata Kalska-Szostko

Beilstein J. Nanotechnol. 2018, 9, 762–770, doi:10.3762/bjnano.9.69

• in the experiment, B) with attached SA and Cd, Cu and Pb; and C) with attached 3-PPA and Cd, Cu and Pb. Raman spectra of A) ferrite nanoparticles; B) SA-modified nanoparticles with attached heavy-metal ions; C) various anhydride-modified nanoparticles with attached Pb ions. Mössbauer spectra of Fe3O4

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• , immobilizing the particles in the matrix and, at the same time, improving the aerogel structure. Polydopamine coating does not affect the magnetic properties of magnetite particles, making the fabricated materials promising for industrial applications. Keywords: aerogel; composite; Fe3O4 nanoparticles

• (Fe3O4) or maghemite (γ-Fe2O3), are common functional additives widely applied in many different branches of science [35][36]. This is mainly thanks to their low price, simplicity of production, biocompatibility and environmental friendliness. There are two commonly used methods of iron oxide MNPs

• polydopamine (PDA) anchors the particles on graphene oxide defects, immobilizes them in the porous matrix, improves the aerogel structure and, what is important, do not affect the magnetic properties of magnetite. Results and Discussion The rGO, rGO-Fe3O4 and rGO-PDA@Fe3O4 aerogels were synthesized as

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• only improve the colloidal stability of Ag NPs but also improve their antibacterial characteristics. A wide range of materials, such as graphene oxide [30][31], carbon nanotubes [32], SiO2 [33], Fe3O4 [34], ZnO [35], CuO [36], TiO2 [37] and others, have been tested as the supports for Ag NPs. Compared

Atomic layer deposition and properties of ZrO₂/Fe₂O₃ thin films

• Kristjan Kalam,
• Helina Seemen,
• Peeter Ritslaid,
• Mihkel Rähn,
• Aile Tamm,
• Kaupo Kukli,
• Aarne Kasikov,
• Joosep Link,
• Raivo Stern,
• Salvador Dueñas,
• Helena Castán and
• Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

• ][16] has been studied as well. Phase stabilization of ZrO2 by Fe doping was investigated by using ALD [17]. Ferromagnetism in ALD-grown Fe3O4/ZrO2/Fe3O4 multilayer nanotubes has been demonstrated [18], while the precursors for distinct solid oxide layers constituting these samples were ferrocene/ozone

• and tetrakis(dimethylamido)zirconium(IV)/water for Fe2O3 and ZrO2, respectively, and Fe2O3 was reduced to Fe3O4 after the growth. In another study [19], ZrO2/Fe thin films were prepared by ALD from β-diketonate precursors and ozone. After annealing at 600 °C in N2 flux for 60 s, the films exhibited

• Fe2O3 phases do not possess lattice structure, allowing commensurate growth on TiN. The epitaxial relationship between magnetite (Fe3O4) and titanium nitride might be considered [41], but magnetite was not recognized in this study in the XRD patterns and, most importantly, the very first layers

Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits

• Fan Tu,
• Martin Drost,
• Imre Szenti,
• Janos Kiss,
• Zoltan Kónya and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2017, 8, 2592–2605, doi:10.3762/bjnano.8.260

• Fe samples were transferred under ambient conditions to the CVD apparatus at the University of Szeged, Hungary. Therefore, oxidation of the Fe deposits, forming Fe2O3 and Fe3O4, is anticipated as discussed previously [32]. However, exposure to H2 for ten minutes before the CVD and simultaneous dosage

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• ) [28][29]. This liquid-crystalline matrix was doped with spherical magnetic particles purchased from Ocean NanoTech. The mean diameter of the Fe3O4 magnetic particles was d = 20 nm. They were coated with oleic acid and dissolved in chloroform. This suspension was admixed to the liquid crystal, and the

• . Magnetization curve of the powder of Fe3O4 magnetic nanoparticles, measured at 285 K. Temperature dependence of the capacitance of 6CB and of two ferronematic samples with different MNP concentrations, . Magnetization curves of neat 6CB and the FN with a MNP concentration of = 10−4 in the nematic phase, as

Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

• Dimitri Vanhecke,
• Dagmar A. Kuhn,
• Dorleta Jimenez de Aberasturi,
• Sandor Balog,
• Ana Milosevic,
• Dominic Urban,
• Diana Peckys,
• Niels de Jonge,
• Wolfgang J. Parak,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2017, 8, 2396–2409, doi:10.3762/bjnano.8.239

• ][45], and characterisation are provided in Supporting Information File 1 (Figures S1–S13). Please note that the synthesis protocol employed for the iron oxide NPs has been reported to yield maghemite (γ-Fe2O3), but as no experimental verification was applied to exclude formation of magnetite (Fe3O4