Facile Controlled Synthesis of Manganese Oxide Hierarchical Microspheres by Hydrothermal Method

2011 ◽  
Vol 688 ◽  
pp. 107-115 ◽  
Author(s):  
Dong Yan Li ◽  
Yun Fa Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Hydrothermal Temperature ◽  
Transmission Electron ◽  
Hierarchical Microspheres

MnO2hierarchical microsphere has been synthesized by a facile and direct hydrothermal reaction between KMnO4and HCl without the aids of catalysts, surfactants or templates. The as-prepared microsphere, as characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis and nitrogen adsorption and desorption, is in form of K0.27MnO2(H2O )0.54, with a flower-like hierarchical microsphere structure and a BET surface area value of 52 m2/g. The morphology of the product can be simply tailed by controlled by reaction temperature or period and crystallinity can be modified by changing the concentrate of KMnO4. In general, excessive KMnO4and low hydrothermal temperature are favor to forming flower-like hierarchical structure. Besides, the formation mechanisms of the hierarchical schemes are proposed.

Controllable synthesis, characterization, and electrochemical properties of manganese oxide nanoarchitectures

2008 ◽  
Vol 23 (3) ◽  
pp. 780-789 ◽  
Author(s):  
Lichun Zhang ◽  
Liping Kang ◽  
Hao Lv ◽  
Zhikui Su ◽  
Kenta Ooi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Manganese Oxide ◽  
Manganese Oxides ◽  
Hydrothermal Reaction ◽  
Reaction Times ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
Transmission Electron

Flowerlike manganese oxide microspheres and cryptomelane-type manganese oxide nanobelts were selectively synthesized by a simple decomposition of KMnO4 under mild hydrothermal conditions without using template or cross-linking reagents. The effect of varying the hydrothermal times and temperatures on the nanostructure, morphology, compositional, and electrochemical properties of the obtained manganese oxides was investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies showed that the flowerlike manganese oxide microspheres could be obtained at relatively low hydrothermal temperatures, while high hydrothermal temperatures were favorable for the formation of cryptomelane-type manganese oxide nanobelts. A morphology and crystalline evolution of the nanostructures was observed as the hydrothermal temperature was increased from 180 to 240 °C. On the basis of changing the temperatures and hydrothermal reaction times, the formation mechanism of cryptomelane-type manganese oxide nanobelts is discussed. Cyclic voltammetry (CV) was used to evaluate the electrochemical properties of the obtained manganese oxide nanostructures, and the results show that the electrochemical properties depend on their shape and crystalline structure. This easily controllable, template-free, and environmentally friendly method has the potential for being used in syntheses of manganese oxide nanomaterials with uniform morphologies and crystal structures.

Synthesis of Flower-Like Mesoporous γ-AlOOH and γ-Al2O3 Nanoarchitectures via an Ionic Liquid-Assisted Hydrothermal Route

NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950046
Author(s):  
Tong Il Kim ◽  
Hak Sung Yun ◽  
Yung Jon ◽  
Gwang Bok Han ◽  
Sung Il Chae ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Hydrothermal Reaction ◽  
Hydrothermal Process ◽  
Reaction System ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Adsorption Desorption

In this work, flower-like [Formula: see text]-AlOOH and [Formula: see text]-Al2O3 nanoarchitectures with excellent surface and mesoporous properties were successfully synthesized in ionic liquid-assisted hydrothermal reaction system. The as-prepared suprastructures were characterized by several techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption/desorption measurement. The formation mechanism of flower-like [Formula: see text]-AlOOH mesoporous crystallites by ionic liquid-assisted hydrothermal process was proposed and discussed. Flower-like [Formula: see text]-Al2O3 nanostructures were obtained by calcining the as-prepared [Formula: see text]-AlOOH at 600∘C for 2[Formula: see text]h, preserving the same morphology.

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

scholarly journals Microwave-assisted preparation of ZnS and ZnSe nanocrystals with different morphologies for photodegradation process of organic dyes

2019 ◽  
Author(s):  
Katarzyna Matras-Postolek ◽  
A. Zaba ◽  
S. Sovinska ◽  
D. Bogdal
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Zinc Sulphide ◽  
Conventional Heating ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Zinc sulphide (ZnS) and zinc selenide (ZnSe) and manganese-doped and un-doped with different morphologies from 1D do 3D microflowers were successfully fabricated in only a few minutes by solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained  nanocrystals, additionally the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The photocatalytic activity of ZnSe, ZnS, ZnS:Mn and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO) and Rhodamine 6G (R6G), respectively. The results show that Mn doped NCs samples had higher coefficient of degradation of organic dyes under ultraviolet irradiation (UV).

Evolution of Crystalline Phase and Morphology of the Products Formed during the Hydrothermal Synthesis of Y2O3 Powders

2011 ◽  
Vol 189-193 ◽  
pp. 1275-1279
Author(s):  
Ying Wang ◽  
Gao Yang Zhao ◽  
Li Yuan
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Treatment ◽  
Crystalline Phase ◽  
Hydrothermal Reaction ◽  
Yttrium Nitrate ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron

The crystalline phase and morphology of the products formed during the synthesis of yttrium oxide via the hydrothermal treatment yttrium nitrate were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Products with high OH/NO3ratios are formed with the increasing of hydrothermal treatment. The crystalline phases are evolved from Y2(OH)5.14(NO3)0.86•H2O toY4O(OH)9(NO3) and finally Y(OH)3. The hydrothermal reaction conditions play an important role in the synthesis of the microstructures. Results show the particle size and final morphology of samples could be controlled by reaction temperature, reaction time, and OH-concentration. Sheets, hexagonal and needle-like Y2O3powders are obtained with the hydrothermal treatment of yittrium nitrate at 180 oC to 200oC for 2-8 hours at pH 9-13.

The Influence of Introduction of Polyethylene Glycol on Synthesis of Bimodal Mesoporous γ-Al2O3

2013 ◽  
Vol 709 ◽  
pp. 89-92
Author(s):  
Xiang Li ◽  
Xin Mei Liu ◽  
Zi Feng Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
X Ray ◽  
Transmission Electron ◽  
Increasing Trend ◽  
Opposite Tendency

In the presence of polyethylene glycol (PEG2W),bimodal mesoporous γ-Al2O3 was successfully synthesized via hydrothermal method. The samples were respectively characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimeter (TG-DSC). Introduction of PEG2W can increase the relative crystallinity of AACH and γ-Al2O3. The BET surface area and pore volume of alumina shows an increasing trend with increasing of PEG2W content, while the pore size shows an opposite tendency. The PEG2W also plays an important role in inducing the formation of the nanorod-like alumina.

scholarly journals Cypermethrin elimination using Fe-TiO2 nanoparticles supported on coconut palm spathe in a solar flat plate photoreactor

2020 ◽  
Vol 29 ◽  
pp. 2633366X2090616
Author(s):  
Ricardo Andrés Solano Pizarro ◽  
Adriana Patricia Herrera Barros
Keyword(s):  
Electron Microscopy ◽  
Flat Plate ◽  
Diffuse Reflectance Spectroscopy ◽  
Cocos Nucifera ◽  
Operating Costs ◽  
Bet Surface Area ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Transmission Electron

In this research, the photocatalytic degradation of cypermethrin using iron-titanium dioxide (Fe-TiO2) nanoparticles supported in a biomaterial was evaluated. The nanoparticles of TiO2 were synthesized by the green chemistry method assisted by ultrasound and doped by chemical impregnation using Fe+3:Ti molar ratios of 0, 0.05, 0.075 and 0.1 to make efficient use of direct sunlight ( λ > 310 nm). All nanoparticles were immobilized on the surface of coconut spathe ( Cocos nucifera). The degradation was carried out at room temperature and natural pH in a flat plate solar reactor, on which the composite material was subjected. The concentration of cypermethrin was determined after 12,000 J m−2 of accumulated radiation from gas chromatography–mass spectrometry and the resulting material was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, and Brunauer-Emmett-Teller (BET) surface area. The best results were achieved with the use of Evonik TiO2 P-25, Fe:Ti = 0 and Fe:Ti = 0.05 in suspension, with percentages of degradation of cypermethrin of 99.84%, 99.62%, and 100%, respectively. However, the materials supported on the biomaterial of coconut allowed to reach degradation percentages higher than 80%, with the advantage that it minimizes operating costs, as they are not necessarily filtering or centrifuging processes to separate the catalyst.

scholarly journals Visible-light-driven photocatalytic degradation of rhodamine B in water by BiOClxI1−x solid solutions

2020 ◽  
Vol 81 (5) ◽  
pp. 1080-1089
Author(s):  
Huan-Yan Xu ◽  
Dan Lu ◽  
Qu Tan ◽  
Xiu-Lan He ◽  
Shu-Yan Qi
Keyword(s):  
Electron Microscopy ◽  
Solid Solutions ◽  
Rhodamine B ◽  
Diffuse Reflectance Spectroscopy ◽  
Bet Surface Area ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Sunlight Irradiation ◽  
Transmission Electron ◽  
Visible Light Driven

Abstract Bismuth oxyhalides (BiOXs, X = Cl, Br and I) are emerging photocatalytic materials with unique layered structure, flexible band structure and superior photocatalytic activity. The purpose of this study was to develop a facile alcoholysis route to prepare BiOClxI1−x nanosheet solid solutions at room temperature. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence emission spectroscopy (PL) and Brunauer–Emmett–Teller (BET) surface area analyzer were used to characterize the as-prepared photocatalysts. These results revealed that two-dimension BiOClxI1−x nanosheet solid solutions could be obtained with high percentage of {001} crystal facets exposed. Moreover, the formation of solid solution could regularly change the optical absorption thresholds and band gaps of BiOClxI1−x photocatalysts. The photocatalytic experiments indicated that BiOCl0.75I0.25 exhibited the highest photocatalytic performance for the degradation of Rhodamine B (RhB) under simulated sunlight irradiation and the photocatalytic process followed a pseudo-first-order kinetic equation. A possible mechanism of RhB photodegradation over BiOClxI1−x solid solutions was proposed based on the structural properties of BiOClxI1−x solid solutions and RhB photosensitization.

scholarly journals Bioactivities of Geranium wallichianum Leaf Extracts Conjugated with Zinc Oxide Nanoparticles

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Banzeer Ahsan Abbasi ◽  
Javed Iqbal ◽  
Riaz Ahmad ◽  
Layiq Zia ◽  
Sobia Kanwal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Energy Dispersive ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Leaf Extracts ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron

This study attempts to obtain and test the bioactivities of leaf extracts from a medicinal plant, Geranium wallichianum (GW), when conjugated with zinc oxide nanoparticles (ZnONPs). The integrity of leaf extract-conjugated ZnONPs (GW-ZnONPs) was confirmed using various techniques, including Ultraviolet–visible spectroscopy, X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, energy-dispersive spectra (EDS), scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The size of ZnONPs was approximately 18 nm, which was determined by TEM analysis. Additionally, the energy-dispersive spectra (EDS) revealed that NPs have zinc in its pure form. Bioactivities of GW-ZnONPs including antimicrobial potentials, cytotoxicity, antioxidative capacities, inhibition potentials against α-amylase, and protein kinases, as well as biocompatibility were intensively tested and confirmed. Altogether, the results revealed that GW-ZnONPs are non-toxic, biocompatible, and have considerable potential in biological applications.

Hydrothermal Synthesis and Morphology Evolution of Perovskite PbTiO3 Crystals with Different Lead Sources

2013 ◽  
Vol 745-746 ◽  
pp. 309-314 ◽  
Author(s):  
Si Min Yin ◽  
Gang Xu ◽  
Zhao Hui Ren ◽  
Chun Ying Chao ◽  
Ge Shen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Reaction System ◽  
Morphology Evolution ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Transmission Electron ◽  
Lead Source

Perovskite lead titanate crystals with various morphologies were successfully synthesized via a hydrothermal reaction route with different lead sources. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were employed to characterize the phase composition and the morphology of the synthesized products. In order to investigate the effect of the lead source on the phase formation and morphology evolution of the synthesized pervoskite PbTiO3 crystals, PbO, PbF2, PbSO4 and Pb (CH3COO)3 ·3H2O, were used as starting precursor lead source introduced into the hydrothermal reaction system, respectively. Accordingly, perovskite PbTiO3 brken cubes, irregular particles, cubic particles, and microplates were obtained, respectively. Based on the experimental results, the effect of lead source was simply discussed.

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