scholarly journals Synthesis, Characterization, and Photocatalytic Performance of Mesoporous α-Mn2O3 Microspheres Prepared via a Precipitation Route

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Thermal Transformation ◽  
Xrd Analysis ◽  
Structural Deformation ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Transmission Electron

α-Mn2O3 microspheres with high phase purity, crystallinity, and surface area were synthesized by the thermal decomposition of precipitated MnCO3 microspheres without the use of any structure directing agents and tedious reaction conditions. The prepared Mn2O3 microspheres were characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) and photoluminescence (PL) studies. The complete thermal transformation of MnCO3 to Mn2O3 was clearly shown by the FTIR and XRD analysis. The electron microscopic images clearly confirmed the microsphere-like morphology of the products with some structural deformation for the calcined Mn2O3 sample. The mesoporous texture generated from the interaggregation of subnanoparticles in the microstructures is visibly evident from the TEM and BET studies. Moreover, the Mn2O3 microstructures showed a moderate photocatalytic activity for the degradation of methylene blue dye pollutant under UV light irradiation, using air as the potential oxidizing agent.

scholarly journals Hydrothermal synthesis of ZnO quantum dot/KNb3O8 nanosheet photocatalysts for reducing carbon dioxide to methanol

2017 ◽  
Vol 8 ◽  
pp. 2264-2270 ◽  
Author(s):  
Xiao Shao ◽  
Weiyue Xin ◽  
Xiaohong Yin
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Uv Light ◽  
Formation Rate ◽  
X Ray Diffraction ◽  
Methanol Production ◽  
X Ray ◽  
Transmission Electron ◽  
Methanol Formation ◽  
Zno Quantum Dots

ZnO quantum dots and KNb3O8 nanosheets were synthesized by a two-step hydrothermal method for the photocatalytic reduction of CO2 to methanol where isopropanol is simultaneously oxidized to acetone . The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and UV–vis absorption spectroscopy (UV–vis). The photocatalytic activity of the materials was evaluated by formation rate of methanol under UV light irradiation at ambient temperature and pressure. The methanol formation rate of pure KNb3O8 nanosheets was found to be 1257.21 μmol/g/h, and after deposition of 2 wt % ZnO quantum dots on the surface of KNb3O8 nanosheets, the methanol production rate was found to increase to 1539.77 μmol/g/h. Thus, the ZnO quantum dots obviously prompted separation of charge carriers, which was explained by a proposed mechanism for this photocatalytic reaction.

Solvothermal Synthesis of Novel 3D Peony-Like TiO2 Microstructures and its Enhanced Photocatalytic Activity

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850056 ◽  
Author(s):  
Yugan He ◽  
Qi Yan ◽  
Xiaoyu Chang ◽  
Meiying Zhu ◽  
Weiwei Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Transmission Electron ◽  
Irradiation Power ◽  
Degussa P25

A TiO2 photocatalyst with peony-like microstructures and a large percentage of exposed {001} facets was synthesized using a facile solvethermal method. The peony-like TiO2 was obtained using HF as a capping agent, TiCl4 as the precursor and ethanol as the solvothermal agent. The parameters which influence the mophology and formation mechanism of the products including the HF concentration, the reaction time and temperature and the solvothermal solvent, were investigated. The samples were characterized using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and N2 adsorption and desorption analysis. As the reaction time or reaction temperature increased, the morphology TiO2 changed from hexagonally assembled microspheres to peony-like microflowers which were composed of stacks of ultrathin nanosheets. The other reaction parameters also play a crucial role in the formation of the TiO2 microstuctures. Photocatalytic experiments showed that the synthesized TiO2 outperformed Degussa P25 in the photodegradation of methelene blue under a very weak UV light irradiation (power: 8[Formula: see text]W, light intensity: 0.4[Formula: see text]mW[Formula: see text]cm[Formula: see text]).

Hydrothermal Synthesis and Photocatalytic Properties of Flower-Like CdS Nanostructures

2011 ◽  
Vol 335-336 ◽  
pp. 460-463 ◽  
Author(s):  
Hong Mei Wang ◽  
Da Peng Zhou ◽  
Yuan Lian ◽  
Ming Pang ◽  
Dan Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Cds Nanostructures

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.

scholarly journals Hydrothermal Synthesis of MnWO4@GO Composite as Non-Precious Electrocatalyst for Urea Oxidation

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Patnamsetty Chidanandha Nagajyothi ◽  
Kisoo Yoo ◽  
Rajavaram Ramaraghavulu ◽  
Jaesool Shim
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Morphological Characterization ◽  
Energy Storage And Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Density Values

In this study, manganese tungstate (MW) and MW/graphene oxide (GO) composites were prepared by a facile hydrothermal synthesis at pH values of 7 and 12. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used for the structural, compositional, and morphological characterization of the nanoparticles (NPs). The XRD analysis revealed that the formation of monoclinic MnWO4 did not have impurities. The SEM and TEM analyses showed that the synthesized NPs were rod-shaped and well-distributed on the GO. The as-synthesized samples can be used as electrocatalysts for the urea oxidation reaction (UOR). The MW@GO-12 electrocatalyst exhibited higher current density values compared to other electrocatalysts. This study provides a new platform for synthesizing inexpensive nanocomposites as promising electrocatalysts for energy storage and conversion applications.

Enhancement of durability of NIR emission of Ag2S@ZnS QDs in water

2017 ◽  
Vol 31 (32) ◽  
pp. 1750297 ◽  
Author(s):  
M. Karimipour ◽  
M. Bagheri ◽  
M. Molaei
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Xrd Analysis ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nir Emission ◽  
Core Shell Structure ◽  
Phase Transmission

Stability of Ag2S@ZnS QDs in water is a crucial concern for their application in biology. In this work, both physical sustainability and emission stability of Ag2S QDs were enhanced using parameter optimization of a pulsed microwave irradiation (MI) method up to 105 days after their preparation. UV–Vis and photoluminescence spectroscopies depicted an absorption and emission about 817 nm and 878 nm, respectively. X-ray diffraction (XRD) analysis showed a growth of Ag2S acanthite phase. Transmission Electron Microscopy (TEM) images revealed a clear formation of Ag2S@ZnS core–shell structure.

Hydrothermal Synthesis and Photocatalytic Properties of ZnO Nanorods

2011 ◽  
Vol 374-377 ◽  
pp. 956-959
Author(s):  
Li Yun Yang ◽  
Gui Peng Feng ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Diffuse Reflectance ◽  
Uv Light ◽  
Zno Nanorods ◽  
Distilled Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Transmission Electron ◽  
Degradation Of Methyl Orange

ZnO2 nanorods were synthesized via hydrothermal treatment of 2ZnCO3•3Zn(OH)2 powder in 30 mass% H2O2 aqueous solution at 170 °C for 12 h, and characterized by means of X-ray diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectra. Besides, the photocatalytic activity of the as-synthesized ZnO2 nanorods was tested for the degradation of methyl orange in distilled water under UV light irradiation.

Synthesis and Characterization of Nano Hydroxylapatite by Reaction Precipitation in Impinging Streams

2010 ◽  
Vol 160-162 ◽  
pp. 1301-1308 ◽  
Author(s):  
Jun Yuan ◽  
Yuan Wu ◽  
Qi Xin Zheng ◽  
Xiao Lin Xie
Keyword(s):  
Electron Microscopy ◽  
Xrd Analysis ◽  
Synthesis And Characterization ◽  
Preparation Process ◽  
X Ray Diffraction ◽  
Excellent Performance ◽  
X Ray ◽  
Operation Conditions ◽  
Transmission Electron

Hydroxylapatite(HAP) nano-whiskers are prepared by reaction-precipitation in the submerged circulative impinging stream reactor(SCISR), with (NH4)2HPO4 and Ca(NO3)2 as the reagents; and the products are characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The results TEM measured indicate that the product prepared under typical operation conditions is average-sized 15nm and 50-70nm long. Multiply repeated experiments illustrates that, because of the excellent performance of the reactor, the preparation process can be easily controlled to yield nano rod/whisker hydroxylapatite with very narrow size distribution.

scholarly journals Investigation of Lithiated Carbons by Transmission Electron Microscopy and X-Ray Diffraction Analysis

1998 ◽  
Vol 548 ◽  
Author(s):  
T. D. Tran ◽  
X. Y. Song ◽  
K. Kinoshita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Lattice Image ◽  
X Ray ◽  
Storage Mechanism ◽  
Transmission Electron ◽  
Diffraction Patterns

ABSTRACTThe microstructures of lithiated synthetic graphite and carbon black were studied by high- resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analysis. Information about the crystal structure of carbon containing various Li compositions can provide useful insights to our understanding of the Li storage mechanism in carbonaceous materials. Samples with compositions of Li0.93C6or Li0.45C6 were found to contain both stage-one and stage-two compounds. These observations are consistent with XRD data. The changes in sample microstructure as the results of lithiation and exposure to electron irradiation were observed by TEM and recorded over several minutes in the microscope environment. Selected area electron diffraction patterns indicated that the lithiated samples quickly changed composition to LiC 24, which appeared to dominate during the brief analysis period. The layer planes in the lattice image of a disordered carbon black after Li insertion are poorly defined, and changes in the microstructure of these lithiated carbons was not readily apparent. Observations on these lithium intercalation compounds as well as the limitation of the experimental procedure will be presented.

The Preparation and Photocatalytic Activity of Ni-Doped ZnS Nanoparticles

2010 ◽  
Vol 148-149 ◽  
pp. 845-848 ◽  
Author(s):  
Qiao Feng Han ◽  
Guo Zhu Diao ◽  
Xiao Heng Liu ◽  
Xin Wang
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Degradation Efficiency ◽  
X Ray Diffraction ◽  
Zns Nanoparticles ◽  
X Ray ◽  
Ethyl Xanthate ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Zinc Sulfide Nanoparticles

Zinc sulfide nanoparticles as undoped and doped with nickel have been prepared by the reaction of Zn(CH3COO)2 and Ni(CH3COO)2 with potassium O-ethyldithiocarbonate (ethyl xanthate, C2H5OCS2k) at 80 in N, N - dimethylformamide (DMF) solution for 24 h. The structures of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their optical properties were studied by UV-Vis spectroscopy. The photocatalytic experiment by degrading methyl orange in aqueous solution under UV light indicated that the degradation efficiency of Ni (6%)-doped ZnS nanoparticles increased to 75% with comparison to 43% of degradation efficiency for undoped ZnS nanoparticles.

Preparation of Chrysotile Nanotubes under Hydrothermal Condition

2011 ◽  
Vol 284-286 ◽  
pp. 688-691 ◽  
Author(s):  
Yang Feng Huang ◽  
Ye Bin Cai ◽  
Hao Liu
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Condition ◽  
Xrd Analysis ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Inner Diameter ◽  
Temperature And Pressure

In a neutral environment, Chrysotile nanotubes have been synthesized by hydrothermal method, with MgO and SiO2powder as the starting materials. X-Ray Diffraction(XRD), Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) are used to characterize the crystal structure and morphology of the as-prepared samples. We found that the diameter of Chrysotile is uniform. Their outer diameter is about 30~50 nm and the inner diameter is about 6~8 nm. The length of them is a few hundred nanometers. The XRD analysis indicates that the as-prepared Chrysotile is a Rhombohedral structures. The results of HRTEM and SAED showed that the {006} planes of serpentine roll up along the [600] direction to form the tubular structure. In addition, the curves of temperature and pressure with time showed that the water might participate in the reaction.

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