scholarly journals Agar Hydrogel Template Synthesis of Mn3O4 Nanoparticles through an Ion Diffusion Method Controlled by Ion Exchange Membrane and Electrochemical Performance

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 503 ◽  
Author(s):  
Qian Xue ◽  
Qiang Zhang
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Photoelectron Spectroscopy ◽  
Ion Exchange Membrane ◽  
Diffusion Method ◽  
Ion Diffusion ◽  
X Ray ◽  
Novel Strategy ◽  
Exchange Membrane ◽  
Mn3o4 Nanoparticles

A novel strategy, ion diffusion method controlled by ion exchange membrane combining with agar hydrogel template, was reported for the synthesis of Mn3O4 nanoparticles without any oxidizing agents. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauere-Emmette-Teller (BET) isotherm were carried out to characterize the structure, morphology, pore size and distribution and specific surface area of the as-prepared nanomaterials. It is shown that the morphology and size of Mn3O4 nanoparticles can be controlled by the concentration of agar hydrogel. All the specific capacitances of the Mn3O4 samples prepared with agar hydrogel template are much higher than that of Mn3O4 prepared without any template agent. The Mn3O4 sample prepared at 1.5 g L−1 of agar hydrogel solution exhibits a highest specific capacitance of 183.0 F g−1 at the current density of 0.5 A g−1, which is increased by 293% compared with that of Mn3O4 synthesized without any template agent. The results indicate that the ion diffusion method controlled by ion exchange membrane combining with agar hydrogel template is a convenient and effective approach for preparing inorganic nanomaterials.

scholarly journals Selective Liquid-Phase Oxidation of Toluene with Molecular Oxygen Catalyzed by Mn3O4 Nanoparticles Immobilized on CNTs under Solvent-Free Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 623
Author(s):  
Yuwei Feng ◽  
Aiwu Zeng
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Benzyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Supported Catalysts ◽  
Liquid Phase Oxidation ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Phase Oxidation ◽  
Mn3o4 Nanoparticles

The catalytic performance of Mn3O4 supported on carbon nanotubes (CNTs) in the liquid-phase oxidation of toluene to benzyl alcohol and benzaldehyde was studied. The supported catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherms and ICP-MS. The results demonstrate that Mn3O4 nanoparticles loaded on CNTs performed better compared with pristine Mn3O4 or CNTs. The main reason for the increased catalytic activity is the dispersion and loading of Mn3O4 in CNTs. By optimizing the reaction temperature, reaction time, catalyst quality, oxygen flow rate and initiator dosage, the optimum reaction conditions were obtained. Using tert-butyl hydroperoxide (TBHP) as the initiator and oxygen as the oxidant, the toluene conversion rate was as high as 24.63%, and benzyl alcohol and benzaldehyde selectivity was 90.49%. The good stability of the catalyst was confirmed by repeating the experiment for four cycles and observing no significant changes in its performance.

γ-Irradiation route to photoluminescent CdS–CdSe with core–shell nanostructures under ambient conditions

2003 ◽  
Vol 81 (5) ◽  
pp. 381-384 ◽  
Author(s):  
Fen Xu ◽  
Xu Zhang ◽  
Jun Lu ◽  
Wang Xi ◽  
Jie Hong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Exchange Reaction ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Core Shell ◽  
Ambient Conditions ◽  
Γ Irradiation ◽  
X Ray ◽  
Ion Exchange Reaction

Photoluminescent CdS–CdSe nanocomposites with core–shell structures were obtained via a novel two-step γ-irradiation process followed by a simple ion-exchange reaction at room temperature and under ambient pressure. To fully characterize CdS–CdSe nanocomposites, X-ray photoelectron spectroscopy, UV–vis absorption spectra, and photoluminescence spectra were recorded, as well as powder X-ray diffraction, transmission electron microscopy, and high-resolution electron microscopy, to confirm the presence of the core–shell nanostructure.Key words: core–shell nanostructure, γ-irradiation, ion-exchange reaction.

Antibacterial silver-diatomite nanocomposite ceramic with low silver release

2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Treatment ◽  
Photoelectron Spectroscopy ◽  
Bactericidal Effect ◽  
Ceramic Filter ◽  
Ceramic Filters ◽  
X Ray ◽  
E Coli ◽  
Point Of Use ◽  
Silver Release

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.

scholarly journals Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Srihasam Saiganesh ◽  
Thyagarajan Krishnan ◽  
Golla Narasimha ◽  
Hesham S. Almoallim ◽  
Sulaiman Ali Alhari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Rare Earth ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

The role of ion exchange membrane in vanadium oxygen fuel cell

2021 ◽  
Vol 629 ◽  
pp. 119271
Author(s):  
Jiří Charvát ◽  
Petr Mazúr ◽  
Martin Paidar ◽  
Jaromír Pocedič ◽  
Jiří Vrána ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Ion Exchange ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Oxygen Fuel

scholarly journals Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Thermoelectric Generator ◽  
Hydrothermal Reaction ◽  
Water Evaporation ◽  
Pani Film ◽  
Portable Devices ◽  
X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

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