Synthesis of Nanoflower Precursors in Two-Phase System via Microwave-Assisted Hydrothermal Method and their In Situ Thermal Convention to NiO

2012 ◽  
Vol 20 ◽  
pp. 43-52 ◽  
Author(s):  
Yan Bin Zhang ◽  
Zhen Feng Zhu ◽  
Wen Jia Zhang ◽  
Yan Li Zhang ◽  
Hui Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Phase System ◽  
The Novel ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Microwave Hydrothermal ◽  
Transmission Electron ◽  
Average Size

The novel nanoflower precursors were successfully fabricated via microwave hydrothermal process in the presence of an anion surfactant Poly (N-vinyl-2-pyrrolidone). Nickel oxide (NiO) with the similar morphology of precursors was also obtained by a simple thermal decomposition of the as-prepared precursors at 400 °C for 2 h in air. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The synthesized NiO nanoclusters have a cubic structure with an average size 500-1000 nm. The specific capacitance of NiO is about 208.4 F/g.

Effect of Cd2+ Concentration on the CdS Crystallites Prepared by Microwave Hydrothermal Process

2012 ◽  
Vol 512-515 ◽  
pp. 203-206
Author(s):  
Jian Feng Huang ◽  
Qin Feng Zhang ◽  
Bao Yun Hu ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Sodium Thiosulfate ◽  
Cadmium Sulphide ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Microwave Hydrothermal ◽  
Transmission Electron ◽  
Assembly Behavior ◽  
Cds Crystallites

Cadmium sulphide (CdS) crystallites were successfully prepared by a microwave hydrothermal (M–H) process using cadmium chloride (CdCl2·H2O) and sodium thiosulfate (Na2S2O3·5H2O) as source material with different Cd2+ concentration. The phase, composition, morphology and optical property of the obtained crystallites were characterized by X–ray diffraction (XRD), field–emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) and ultraviolet–visible spectrophotometer (UV–Vis). Results show that the crystalline structure of the prepared CdS crystallites changes regularly with the increase of Cd2+ concentration and the corresponding morphology of CdS crystallites transforms from tetrahedron to quasi-sphere. The quasi-spherical CdS is derived from the nanoparticles-assembly behavior. And with the increase of Cd2+ concentration, the decrease in CdS crystallite size is observed. Obvious blue–shift is detected in the UV–Vis absorption when Cd2+ concentration reaches 0.60 mol/L.

Controlled Synthesis of Hierarchical Flower-Like CuS Spheres by a Facile Microwave Hydrothermal Method

2012 ◽  
Vol 512-515 ◽  
pp. 265-268 ◽  
Author(s):  
Hui Qi ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Cetyltrimethylammonium Bromide ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Hydrothermal ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Average Size ◽  
20 Nm

–Hierarchical flower–like CuS spheres have been synthesized by a facile microwave hydrothermal (MH) method using cetyltrimethylammonium bromide (CTAB) as the surfactant. The as–prepared CuS crystallites under different CTAB contents were characterized by X–ray diffraction (XRD), field–emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Results show that the CTAB–assisted CuS particles have hierarchical flower–like microstructures that were assembled by thin nanoflakes with thickness of 10~20 nm. The corresponding HRTEM images reveal that these nanoflakes are composed of many nanoparticles with average size of about 7 nm. Moreover, when increasing the CTAB contents from 0 g⁄mL to 0.02 g⁄mL, the as–prepared CuS particles were found to have better dispersion stability with decreased average sizes of the hierarchical flower–like spheres. Comparing with the bulk CuS particles, the related UV–vis absorption spectrum of the as–prepared crystallites exhibits an obvious red shift with the absorption peak at 739 nm.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

Late Mesozoic—Cenozoic clay mineral successions of southern Iran and their palaeoclimatic implications

Clay Minerals ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 191-203 ◽  
Author(s):  
F. Khormali ◽  
A. Abtahi ◽  
H. R. Owliaie
Keyword(s):  
Electron Microscopy ◽  
Upper Cretaceous ◽  
Sedimentary Rocks ◽  
X Ray Diffraction ◽  
Humid Climate ◽  
X Ray ◽  
Late Mesozoic ◽  
Southern Iran ◽  
Transmission Electron

AbstractClay minerals of calcareous sedimentary rocks of southern Iran, part of the old Tethys area, were investigated in order to determine their origin and distribution, and to reconstruct the palaeoclimate of the area. Chemical analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and thin-section studies were performed on the 16 major sedimentary rocks of the Fars and Kuhgiluyeh Boyerahmad Provinces.Kaolinite, smectite, chlorite, illite, palygorskite and illite-smectite interstratified minerals were detected in the rocks studied. The results revealed that detrital input is possibly the main source of kaolinite, smectite, chlorite and illite, whilein situneoformation during the Tertiary shallow saline and alkaline environment could be the dominant cause of palygorskite occurrences in the sedimentary rocks.The presence of a large amount of kaolinite in the Lower Cretaceous sediments and the absence or rare occurrence of chlorite, smectite, palygorskite and illite are in accordance with the warm and humid climate of that period. Smaller amounts of kaolinite and the occurrence of smectite in Upper Cretaceous sediments indicate the gradual shift from warm and humid to more seasonal climate. The occurrence of palygorskite and smectite and the disappearance of kaolinite in the late Palaeocene sediments indicate the increase in aridity which has probably continued to the present time.

Size dependent behavior of Fe3O4crystals during electrochemical (de)lithiation: an in situ X-ray diffraction, ex situ X-ray absorption spectroscopy, transmission electron microscopy and theoretical investigation

2017 ◽  
Vol 19 (31) ◽  
pp. 20867-20880 ◽  
Author(s):  
David C. Bock ◽  
Christopher J. Pelliccione ◽  
Wei Zhang ◽  
Janis Timoshenko ◽  
K. W. Knehr ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size Dependent ◽  
Transmission Electron ◽  
Dependent Behavior ◽  
X Ray Absorption

Crystal and atomic structural changes of Fe3O4upon electrochemical (de)lithiation were determined.

scholarly journals A comparative study on the VOCs sensing behaviors of various ZnO nanostructures

2020 ◽  
Vol 9 (4) ◽  
pp. 117-122
Author(s):  
Vuong Nguyen Minh ◽  
Dung Dinh Tien ◽  
Hieu Hoang Nhat ◽  
Nghia Nguyen Van ◽  
Truong Nguyen Ngoc Khoa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hierarchical Structure ◽  
Hydrothermal Process ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
Electrospinning Technique ◽  
Transmission Electron ◽  
Volatile Organic ◽  
Wet Chemical

The volatile organic compounds (VOCs) sensing layers were studied using ZnO nanomaterials with different morphologies including hierarchical nanostructure (ZnO-H), nanorods (ZnO-NRs), commercial nanoparticles (ZnO-CNPs) and wet chemical synthesized nanoparticles (ZnO-HNPs). ZnO hierarchical structure was fabricated by an electrospinning technique followed by hydrothermal process. ZnO vertical nanorods structure was fabricated by hydrothermal method, while ZnO nanoparticles based sensors were prepared from commercial powder and wet chemical method. The morphology and properties of the fabricated samples were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). VOCs sensing responses toward acetone, ethanol and methanol with respect to altered ZnO nanostructureswas systematically compared at different working temperatures. The enhanced response at low working temperatures induced by theopen space hierarchical structure was observed. The VOCs sensing mechanisms of the ZnO nanostructures based sensing layer were also explained and discussed in detail. 

scholarly journals Synthesis of Polyaniline coated Graphene Oxide @ SrTiO3 Nanocube Nanocomposites for Enhanced Removal of Carcinogenic Dyes from Aqueous Solution

2016 ◽  
Author(s):  
Syed Shahabuddin ◽  
Norazilawati Muhamad Sarih ◽  
Muhammad Afzal Kamboh ◽  
Hamid Rashidi Nodeh ◽  
Sharifah Mohamad
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Methyl Orange ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polymerization Method

The present investigation highlights the synthesis of polyaniline (PANI) coated graphene oxide doped with SrTiO3 nanocube nanocomposites through facile in-situ oxidative polymerization method for the efficient removal of carcinogenic dyes, namely, the cationic dye methylene blue (MB) and the anionic dye methyl orange (MO). The synthesised nanocomposites were characterised by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The adsorption efficiencies of graphene oxide (GO), PANI homopolymer and SrTiO3 nanocubes-doped nanocomposites were assessed by monitoring the adsorption of methylene blue and methyl orange dyes from aqueous solution. The adsorption efficiency of nanocomposites doped with SrTiO3 nanocubes were found to be of higher magnitude as compared with undoped nanocomposite. Moreover, the nanocomposite with 2 wt% SrTiO3 with respect to graphene oxide demonstrated excellent adsorption behaviour with 99% and 91% removal of MB and MO respectively, in a very short duration of time.

Sign in / Sign up

Export Citation Format

Share Document