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TEM (at different scale) and HRTEM images of nano-particles showing 001 and 400 atomic lattice planes and corresponding FFT diffractogram.
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Vanadium pentoxide (V2O5) nano-particles have been synthesized by flame spray pyrolysis method to investigate their cathodic performance in Li-ion rechargeable batteries. They were characterized by surface area (Brunauer-Emmett-Teller, BET method), scanning electron microscopy (SEM), transmission electron microscopy-energy dispersive spectrometry (...
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... and morphology SEM and TEM images given in Figs. 2 and 3 show that the par- ticles prepared were at nano size and mostly spherical shape. SEM pictures show agglomeration of the primary particles. TEM images indicate spherical primary particles necking and forming chain- like aggregate structures. HRTEM picture of a V 2 O 5 nanoparticle (given in Fig. 3) showing atomic lattice fringes and ...
Context 2
... and morphology SEM and TEM images given in Figs. 2 and 3 show that the par- ticles prepared were at nano size and mostly spherical shape. SEM pictures show agglomeration of the primary particles. TEM images indicate spherical primary particles necking and forming chain- like aggregate structures. HRTEM picture of a V 2 O 5 nanoparticle (given in Fig. 3) showing atomic lattice fringes and corresponding FFT diffractogram were evidence for crystalline structures. From HRTEM picture, d-spacings of 4.4 ˚ A and 2.8 ˚ A were observed for (0 0 1) and (4 0 0) planes of V 2 O 5 phase, respectively. TEM-EDS result showed stoichiometric elemental V:O (∼2:5) atomic ...
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In spite of the remarkable properties of CdO, there are only a few reports on CdO nanostructures, especially on isolated NPs. In this paper, we analyze the growth of isolated CdO nanoparticles (NPs) on 0.5° miscut r-sapphire substrates by using the spray pyrolysis methodology in its classical configuration. A systematic study has been performed to...
Citations
... This approach is used for the production of nano-TiO 2 in an FSP system in our laboratory. Details of the FSP set-up can be found in references [13,14]. The nozzle used in this work came with a standard distance ring (DR) on the air cap, which guaranteed after disassembly and assembly the correct air-cap position number 4 (P4) with a distance ring height of 3.01mm [15]. ...
... Eq. (13) can be used to calculate the value of A min for an upstream pressure above the critical pressure. This equation can also be used to find the required dispersion gas flow rate Q s for a desired pressure drop across the nozzle throat. ...
The most critical part of the flame spray pyrolysis (FSP) process is the nozzle, since it plays a key role in setting the
spray properties. In this study, we developed an approach to adjust the nozzle throat gap size for a desired
dispersion gas flow rate and upstream pressure, based on the external size and shape of a two phase external
mixing nozzle. An equation was derived and validated by comparing the predicted gas flow rates with the data
provided in a commercial nozzle supplier chart. Experiments were also conducted in our lab-scale FSP reactor to
test the validity of the predictions. The approach developed here was found to closely predict the gap size
necessary to pass the required dispersion gas flow at a desired pressure drop. Error in predictions was found to be
less than 3% at an upstream pressure range of 3–10 bars. The isentropic flow assumption for perfect gases across
the convergent-divergent nozzle was found to fail below 2 bars, consistent with the theory applied. By using the
method here, the nozzle setting for a desired operation in an FSP process can be easily done, minimizing the timeconsuming trial and error steps needed otherwise.
... Lithium-ion batteries have high energy density, power density, long life, and environmental friendliness [266]. They have a wide application area from small portable devices to electronically powered vehicles [267]. Lithium-ion batteries do not use a redox reaction to generate electricity. ...
Supercapacitors and batteries are among the most promising electrochemical energy storage technologies available today. Indeed, high demands in energy storage devices require cost-effective fabrication and robust electroactive materials. In this review, we summarized recent progress and challenges made in the development of mostly nanostructured materials as well as fabrication routes for energy storage devices. Indeed, we systematically sorted out the design principles of electrode materials such as lithium-ion, lead-acid, lithium-sulfur, nickel-cadmium, nickel-metal hydride, and sodium-ion for rechargeable batteries electrode and supercapacitors (SCs) electrode materials following by systematic discussions on electric double-layer capacitors, pseudocapacitors, and hybrid SCs behavior.
... Accordingly, for the last decade, many experimental attempts have been conducted to synthesize the high-performance V 2 O 5 nanostructures. For example, hydrothermal (Jayaraj et al., 2018;Pan et al., 2018), electrospinning (Berenguer et al., 2017), flame spray pyrolysis (Sel et al., 2014), sol-gel (Sh. T., 2021), chemical vapor deposition (Yin et al., 2012), ion exchange (Liu et al., 2015a), sonication (Ahmad et al., 2010;Karthik et al., 2020), and laser irradiation (Lazauskas et al., 2020) are typical ways to fabricate high-quality V 2 O 5 . ...
To materialize the excellent photocatalyst for crystal violet dye-degradation, the graphitic carbon-encapsulated vanadium pentoxide (GC-V2O5) nanocomposites were synthesized through the simple sonication method by using the green tea waste-derived GC nanoflakes and the sonochemically synthesized V2O5 nanorods. The nanocomposites were confirmed to comprise an aggregated morphology, in which the orthorhombic V2O5 nanorods were well anchored with the intertwingled GC nanoflakes. Owing to the encapsulation of defective V2O5 by conductive GC, the GC-V2O5 nanocomposites exhibited the enhanced photocatalytic dye-degradation efficiency up to 98.4% within 105 min. Namely, the encapsulated GC nanosheets might compensate the native defects (i.e., charge traps) on the V2O5 surface; hence, the charge transport could be enhanced during the dye-degradation process while the photocarrier recombination could be suppressed. The results suggest the conducting layer-encapsulated semiconducting oxide nanocomposites (e.g., GC-V2O5) to be of good use for future green environmental technology, particularly, as a superb photocatalyst for dye degradation.
... However, few studies have attempted the flame aerosol synthesis (FAS) method, which is not a conventional technique but has the significant advantage of scale-up capability [5]. The FAS method has been proved to successfully synthesize multiple metal oxides such as Al 2 O 3 [16], SiO 2 [17], TiO 2 [18], V 2 O 5 [19], Mn 2 O 3 [20], Fe 2 O 3 [21] and ZnO [22]. In this study, we used the FAS method for the synthesis of YAG powder and systematically investigated the phase formation, morphology, and infrared transmittance properties of the YAG powder. ...
In this study, the flame aerosol synthesis (FAS) method was used to synthesize a yttrium aluminum garnet (Y3Al5O12, YAG) nanopowder. The dominant reaction route in the FAS method is the liquid route; this shaped the primary morphology of the YAG nanopowder into hollow and solid spheres. The effects of precursor concentration and annealing parameters were systematically investigated. At a precursor concentration of 0.4 mol L⁻¹ and an annealing temperature of 1400 °C, the YAG nanopowder exhibited excellent infrared transmittance. Compared to other conventional synthesis methods, the FAS method has the advantages of high yield, low cost, and ease of obtaining a nanosized powder. The FAS method is thought to be one of the best choices for the large-scale production of YAG powders.
... The FAS method is not a conventional method but has the significant advantage of scale-up capability, providing tens or even hundreds of grams per minute. The fabrication of multiple metal oxides such as Al 2 O 3 [7], SiO 2 [8], TiO 2 [9], V 2 O 5 [10], Mn 2 O 3 [11], and Fe 2 O 3 [12], and YAlO 3 [13,14] has been investigated. Both pure and doped ZnO were also fabricated using the FAS method [15][16][17][18][19][20][21][22][23]. ...
In this study, nanosized ZnO and Zn1−xFexO powders were synthesized using the flame aerosol synthesis (FAS) method. The microstructure of the ZnO powder shows a significant difference with different precursor concentrations. By adding Fe to the precursor, nanosized Zn1−xFexO powder (x = 0~0.1) can be easily fabricated. The phase formation, microstructure, and infrared absorption properties were systematically investigated by XRD, SEM, TEM, and IR. With the substitution of Fe into the Zn site, lattice distortion occurred, resulting in excellent infrared absorption properties. Compared to other conventional synthesis methods, the FAS method has the advantages of high yield, high crystallinity, and low cost; furthermore, nanosized powder is easily obtained. The FAS method is believed to be one of the best choices for the large-scale production of ZnO and Zn1−xFexO powders.
... Wallace et al. (2013) and Tricoli et al. (2016) reported the synthesis of nZnO by this method. Many other researchers also reported the production of other MONPs like Mn 2 O 3 , ZrO 2 , WO 3 , Fe 2 O 3 , SnO 2 , Al 2 O 3 , and V 2 O 5 (Laine et al., 2006;Sel et al., 2014;Tricoli et al., 2008;Pokhrel et al., 2010). ...
Metal oxide nanoparticles (MONPs) with an inorganic core composed of a metallic element bonded to oxide (O2 −) anions have been widely used in fertilizers, water treatment, health, cosmetics, electronics, food packaging, and even food products. The production, usage, and disposal of MONPs-containing products are potential routes for environmental exposure into aquatic and terrestrial compartments where the MONPs are subjected to various dynamic processes such as physical, chemical, and biological transformations. These transformation pathways can have strong implications on fate, transport, persistence, bioavailability, and toxicity. The discipline of “nanotoxicology” has developed to study the interactions of NPs with biological systems, toxicity based on NPs’ properties, and levels related to environmental health. This chapter will contribute to understanding the dynamics, interactions, and toxicity perspectives, and help manufacturers, regulation agencies, environmental engineers, scientists, and students to understand the developments of MONPs, their environmental interactions, and potential toxicity limits in commercial products.
... This approach is used for the production of nano-TiO 2 in an FSP system in our laboratory. Details of the FSP set-up can be found in references [13,14]. The nozzle used in this work came with a standard distance ring (DR) on the air cap, which guaranteed after disassembly and assembly the correct air-cap position number 4 (P4) with a distance ring height of 3.01mm [15]. ...
... Eq. (13) can be used to calculate the value of A min for an upstream pressure above the critical pressure. This equation can also be used to find the required dispersion gas flow rate Q s for a desired pressure drop across the nozzle throat. ...
The most critical part of the flame spray pyrolysis (FSP) process is the nozzle, since it plays a key role in setting the spray properties. In this study, we developed an approach to adjust the nozzle throat gap size for a desired dispersion gas flow rate and upstream pressure, based on the external size and shape of a two phase external mixing nozzle. An equation was derived and validated by comparing the predicted gas flow rates with the data provided in a commercial nozzle supplier chart. Experiments were also conducted in our lab-scale FSP reactor to test the validity of the predictions. The approach developed here was found to closely predict the gap size necessary to pass the required dispersion gas flow at a desired pressure drop. Error in predictions was found to be less than 3% at an upstream pressure range of 3–10 bars. The isentropic flow assumption for perfect gases across the convergent-divergent nozzle was found to fail below 2 bars, consistent with the theory applied. By using the method here, the nozzle setting for a desired operation in an FSP process can be easily done, minimizing the time-consuming trial and error steps needed otherwise.
... It has been reported before by some researchers that one of the materials with low band gap energy, of around 2.8 eV, and some stability in aqueous solutions is the V 2 O 5 -based photocatalysts [13], potentially active under irradiation with visible light and investigated in the last years [14][15][16][17]. The synthesis of V 2 O 5 has been reported by using techniques as the hydrothermal synthesis [18], solgel technique [19], thermal decomposition of several precursors as ammonium metavanadate (NH 4 VO 3 ) [20], flamespray pyrolysis [21,22] magnetron sputtering, electron-beam evaporation, and pulsed laser deposition [23,24], obtaining several morphologies as nanobelts [18,19], nanowires [18], nanoribbons, nanopowders [18,21], and also thin films [19,[21][22][23]. Thin films and powders have been obtained with different textural and structural properties related in some cases with their photocatalytic activity [24][25][26]. ...
... It has been reported before by some researchers that one of the materials with low band gap energy, of around 2.8 eV, and some stability in aqueous solutions is the V 2 O 5 -based photocatalysts [13], potentially active under irradiation with visible light and investigated in the last years [14][15][16][17]. The synthesis of V 2 O 5 has been reported by using techniques as the hydrothermal synthesis [18], solgel technique [19], thermal decomposition of several precursors as ammonium metavanadate (NH 4 VO 3 ) [20], flamespray pyrolysis [21,22] magnetron sputtering, electron-beam evaporation, and pulsed laser deposition [23,24], obtaining several morphologies as nanobelts [18,19], nanowires [18], nanoribbons, nanopowders [18,21], and also thin films [19,[21][22][23]. Thin films and powders have been obtained with different textural and structural properties related in some cases with their photocatalytic activity [24][25][26]. ...
... It has been reported before by some researchers that one of the materials with low band gap energy, of around 2.8 eV, and some stability in aqueous solutions is the V 2 O 5 -based photocatalysts [13], potentially active under irradiation with visible light and investigated in the last years [14][15][16][17]. The synthesis of V 2 O 5 has been reported by using techniques as the hydrothermal synthesis [18], solgel technique [19], thermal decomposition of several precursors as ammonium metavanadate (NH 4 VO 3 ) [20], flamespray pyrolysis [21,22] magnetron sputtering, electron-beam evaporation, and pulsed laser deposition [23,24], obtaining several morphologies as nanobelts [18,19], nanowires [18], nanoribbons, nanopowders [18,21], and also thin films [19,[21][22][23]. Thin films and powders have been obtained with different textural and structural properties related in some cases with their photocatalytic activity [24][25][26]. ...
V 2 O 5 powders modified with different theoretical silver contents (1, 5, 10, 15, and 20 wt% as Ag 2 O) were obtained with acicular morphologies observed by scanning electron microscopy (SEM). Shcherbinaite crystalline phase is transformed into the Ag 0.33 V 2 O 5 crystalline one with the incorporation and increase in silver content as was suggested by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. With further increase in silver contents the Ag 2 O phase appears. Catalysts were active in photocatalytic degradation of malachite green dye under simulated solar light, which is one of the most remarkable facts of this work. It was found that V 2 O 5 -20Ag was the most active catalytic formulation and its activity was attributed to the mixture of coupled semiconductors that promotes the slight decrease in the rate of the electron-hole pair recombination.
... The organometallic precursor solution was decomposed at the high temperature flame forming metal oxide, carbon dioxide and water. In FSP method, a high temperature flame is the main factor to produce nano-sized particles, however, there are other controlling factors as well, for example, feeding rate of O 2 and type of precursors [30][31][32] which influence the production rate and properties of nanoparticle. ...
Iron doped aluminium oxide nanoparticles are of interest for number of applications (e.g. water treatment, catalytic conversion of exhaust gases) due to their high surface area, hardness, catalytic and magnetic properties. In
the present study, flame spray pyrolysis (FSP) was employed for the synthesis of Fe/Al2O3 nanoparticles. Precursor solutions of aluminium acetylacetonate (0.2 mol·L−1) and ferrocene (0 to 0.2 mol·L−1) in toluene were used
to synthesise pure and iron (Fe) doped Al2O3. The particle composition and morphology were studied and effect
of iron concentration was analysed. It was found that in the absence of the iron precursor, FSP produced a mixture
of two Al2O3 polymorphs: θ-Al2O3 and η-Al2O3. The addition of ferrocene as an iron precursor was found to suppress formation of θ-Al2O3. At an iron molar concentration of 0.2 mol·L–1 mainly hercynite, FeAl2O4, was observed. Furthermore, increasing the iron concentration caused a linear shift of the X-ray diffraction peaks from
positions corresponding to η-Al2O3 to those of FeAl2O4. This indicates the formation of a solid solution
(FexAl2O3 + x) at intermediated concentrations. It was also found that the primary particle size, which was
below 10 nm, did not significantly change with the increased iron concentration and was comparable to the
mean crystallite size indicating that size of these single crystalline primaries is determined by the synthesis process rather than the chemistry of the product. However, the hydrodynamic size was around 180 nm indicating
that the particles are agglomerates in the water suspension. Additionally, zeta potential of the nanoparticles
was found to decrease slightly with increasing iron content, though in all cases it was above 50 mV. Finally,
the potential of synthesized nanoparticles was examined for the removal of fluoride because fluoride causes
harmful health effects to human health at elevated concentrations. The results of fluoride removal using synthesized nanoparticles produced in this study showed that the highest fluoride removal efficiency was observed for
the sample having no iron content.
... The organometallic precursor solution was decomposed at the high temperature flame forming metal oxide, carbon dioxide and water. In FSP method, a high temperature flame is the main factor to produce nano-sized particles, however, there are other controlling factors as well, for example, feeding rate of O 2 and type of precursors [30][31][32] which influence the production rate and properties of nanoparticle. ...
