scholarly journals Hydrothermal Synthesis of Boron-Doped MnO2and Its Decolorization Performance

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ming Sun ◽  
Ting Lin ◽  
Gao Cheng ◽  
Fei Ye ◽  
Lin Yu

To functionalize MnO2with foreign ions is one of the commonly used methods to improve the adsorption/oxidation properties of MnO2. Boron-doped MnO2was prepared by the reaction of MnSO4, KMnO4, and boric acid by a facile hydrothermal method. Boron-MnO2was characterized by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction pattern (SAED), and X-ray photo-electron spectroscopy (XPS) techniques. The characterization of XPS and EDX confirms that boron has been doped into MnO2, but the boron dopant has no obvious effect on the crystallization of MnO2as shown by the results of XRD and Raman characterization. The boron-doped MnO2nanorods display high performance in the methyl orange degradation with a decolorization degree of 90% in 2 min (5% B-MnO2dosage, 5 mg; methyl orange concentration, 20 mg L−1).

2010 ◽  
Vol 152-153 ◽  
pp. 1222-1226
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang ◽  
Gao Rong Han

Single-crystal PbTiO3 nanoflakes have been synthesized successfully by a hydrothermal method. The as-prepared powders were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). It was found that KOH concentration played a key role in the growth of single-crystal tetragonal perovskite PbTiO3 nanoflakes, and the morphology of PbTiO3 crystallites can be controlled by adjusting the KOH concentration.


2012 ◽  
Vol 1408 ◽  
Author(s):  
Cagla Ozgit ◽  
Fatma Kayaci ◽  
Inci Donmez ◽  
Engin Cagatay ◽  
Tamer Uyar ◽  
...  

ABSTRACTAl2O3 and AlN nanotubes were fabricated by depositing conformal thin films via atomic layer deposition (ALD) on electrospun nylon 66 (PA66) nanofiber templates. Depositions were carried out at 200°C, using trimethylaluminum (TMAl), water (H2O), and ammonia (NH3) as the aluminum, oxygen, and nitrogen precursors, respectively. Deposition rates of Al2O3 and AlN at this temperature were ∼1.05 and 0.86 Å/cycle. After the depositions, Al2O3- and AlN-coated nanofibers were calcinated at 500°C for 2 h in order to remove organic components. Nanotubes were characterized by using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). AlN nanotubes were polycrystalline as determined by high resolution TEM (HR-TEM) and selected area electron diffraction (SAED). TEM images of all the samples reported in this study indicated uniform wall thicknesses.


2010 ◽  
Vol 97-101 ◽  
pp. 2144-2147
Author(s):  
Xin Yu Yang ◽  
Wei Dong Xiang ◽  
Xi Yan Zhang ◽  
Hai Tao Liu

L-Cystine was successfully used as a novel kind of sulfur source to synthesize the nanostructure of ribbon-like Sb2S3. The nanoribbons were usually tens of micronmeters in length, typically 100-300 nm in width. The nanostructure of ribbon-like Sb2S3 were examined using diverse techniques including X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffraction, and high-resolution TEM.


2006 ◽  
Vol 21 (11) ◽  
pp. 2941-2947 ◽  
Author(s):  
Hongjun Zhou ◽  
Tae-Jin Park ◽  
Stanislaus S. Wong

Bismuth titanate (Bi2Ti2O7) nanotubes were successfully synthesized with an alumina template-based sol-gel technique. As-synthesized nanotubes are smooth and uniform with diameters ranging from 180 to 330 nm and lengths varying from 7 to 12 μm. Extensive characterization of as-prepared samples has been performed using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy-dispersive x-ray spectroscopy (EDS), and selected-area electron diffraction (SAED). Photocatalytic studies indicate that as-prepared nanotubes possess higher photocatalytic activity than the corresponding bulk sample prepared without the use of an alumina template.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1512
Author(s):  
Yuhan Liu ◽  
Meiling Zhang ◽  
Jinjun Cheng ◽  
Yue Zhang ◽  
Hui Kong ◽  
...  

Glycyrrhizae Radix et Rhizoma (GRR) is one of the commonly used traditional Chinese medicines in clinical practice, which has been applied to treat digestive system diseases for hundreds of years. GRR is preferred for anti-gastric ulcer, however, the main active compounds are still unknown. In this study, GRR was used as precursor to synthesize carbon dots (CDs) by a environment-friendly one-step pyrolysis process. GRR-CDs were characterized by using transmission electron microscopy, high-resolution TEM, fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. In addition, cellular toxicity of GRR-CDs was studied by using CCK-8 in RAW264.7 cells, and the anti-gastric ulcer activity was evaluated and confirmed using mice model of acute alcoholic gastric ulcer. The experiment confirmed that GRR-CDs were the spherical structure with a large number of active groups on the surface and their particle size ranged from 2 to 10 nm. GRR-CDs had no toxicity to RAW264.7 cells at concentration of 19.5 to 5000 μg/mL and could reduce the oxidative damage of gastric mucosa and tissues caused by alcohol, as demonstrated by restoring expression of malondialdehyde, superoxide dismutase and nitric oxide in serum and tissue of mice. The results indicated the explicit anti-ulcer activity of GRR-CDs, which provided a new insights for the research on effective material basis of GRR.


2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.


2010 ◽  
Vol 43 (5) ◽  
pp. 990-997 ◽  
Author(s):  
Jie Ma ◽  
Qingsheng Wu

A facile oxides–hydrothermal (O–HT) method is demonstrated to prepare high-purity monazite-type LaPO4nanomaterials. In this approach, La2O3and P2O5powder are first directly used as precursors under additive-free hydrothermal conditions. The as-prepared samples are characterized with X-ray diffraction, Fourier transform IR spectroscopy, thermogravimetry, scanning electron microscopy, transmission electron microscopy (high-resolution TEM, energy dispersive spectroscopy) and selected-area electron diffraction. The typical sample obtained at 433 K in 24 h comprises uniform single-crystal nanofibres with a diameter of ∼15–28 nm and an aspect ratio of 30–50. The influences of treatment time, synthesis temperature and P/La molar ratio are investigated. The phase transition from hexagonal hydrate to monoclinic anhydrous lanthanum phosphate and the growth process of nanofibres are revealed by the experimental results. The formation mechanism of the monoclinic LaPO4is discussed. The result indicates that the P/La ratio does not influence the composition and crystal phase but changes the morphology of the product in the O–HT system.


2019 ◽  
Vol 26 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Xian-sheng Wang ◽  
Yu-duo Zhang ◽  
Qiao-chu Wang ◽  
Bo Dong ◽  
Yan-jia Wang ◽  
...  

AbstractZnO is modified by Cu2O by the process of precipitation and calcination. X-ray diffraction has shown that Cu2O/ZnO catalysts are made of highly purified cubic Cu2O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu2O. Due to the doping of Cu2O, the absorption range of the Cu2O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu2O/ZnO on methyl orange solution is obviously enhanced compared to Cu2O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu2O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu2O.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 744 ◽  
Author(s):  
Jinyu Huang ◽  
Feifei Li ◽  
Baozhong Liu ◽  
Peng Zhang

The hydrogen generated via the water splitting method is restricted by the high level of theoretical potential exhibited by the anode. The work focuses on synthesizing a bifunctional catalyst with a high efficiency, that is, a nickel phosphide doped with the reduced graphene oxide nanosheets supported on the Ni foam (Ni2P/rGO/NF), via the hydrothermal approach together with the calcination approach specific to the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The Raman, X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscope (TEM), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), as well as elemental mapping, are adopted to study the composition and morphology possessed by Ni2P/rGO/NF. The electrochemical testing is performed by constructing a parallel two-electrode electrolyzer (Ni2P/rGO/NF||Ni2P/rGO/NF). Ni2P/rGO/NF||Ni2P/rGO/NF needs a voltage of only 1.676 V for driving 10 mA/cm2, which is extremely close to Pt/C/NF||IrO2/NF (1.502 V). It is possible to maintain the current density for no less than 30 hours. It can be demonstrated that Ni2P/rGO/NF||Ni2P/rGO/NF has commercial feasibility, relying on the strong activity and high stability.


2013 ◽  
Vol 101 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Gupta ◽  
S. K. Gupta ◽  
S. K. Aggarwal

Abstract Nanoparticles of thorium oxalate were synthesized by the reaction of thorium nitrate and ammonium oxalate by the microemulsion method. The Th02 nanoparticles were obtained by heating thorium oxalate nanoparticles at 500 °C in air. The oxalate and oxide nanoparticles of thorium were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and selected area electron diffraction (SAED). X-ray diffraction studies showed the mono-phasic nature of the powder thoria. The particle size was obtained from X-ray line broadening (~l0 nm) and transmission electron microscopy (~l0 nm). Dynamic light scattering (DLS) was used to calculate the average grain size of the particles. SAED confirmed the nanocrystalline nature of thoria particles. High resolution transmission electron microscopy (HRTEM) was also carried out to understand the morphology of the system. The monodisperse nanoparticles of thoria are promising for future reactor technologies.


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