Preparation of Ni-Doped MoS2 Microsphere and its Superior Electrocatalytic Hydrogen Evolution Ability

2013 ◽  
Vol 871 ◽  
pp. 206-210 ◽  
Author(s):  
Yue Chan Xie ◽  
Yue Ming Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Undoped Sample ◽  
Cathodic Current ◽  
X Ray ◽  
Effective Hydrogen ◽  
Scanning Electron ◽  
Mos2 Catalyst

To find a cheap and effective hydrogen evolution reaction catalyst, a series of Ni-doped MoS2 microspheres consisting of MoS2 nanosheets have been prepared via hydrothermal synthesis and characterized by scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). Their performance as electrochemical hydrogen evolution reaction (HER) catalyst was studied. It is found that the Ni-doped MoS2 exhibited superior electrocatalytic activity in the HER to undoped MoS2 catalysts. The overpotential of Ni-doped MoS2 has decreased compared with that of undoped sample, indicating an improved activity in HER. Furthermore, the cathodic current for the Ni-doped MoS2 catalyst is about 9 times as much as that for undoped MoS2. Based on our findings, the resulting Ni-doped MoS2 might be promising inexpensive alternative to platinum catalysts in hydrogen production.

Electrochemical Characteristics of the Amorphous-Nanocrystal Ni–Mo Cathodes in Sodium Hydroxide Solution

2015 ◽  
Vol 667 ◽  
pp. 280-285
Author(s):  
Ning Li ◽  
Jian Meng Huang ◽  
Wei Zeng Chen ◽  
Bin Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Evolution ◽  
Sodium Hydroxide Solution ◽  
Electrochemical Characteristics ◽  
Phase Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modern Technologies ◽  
Scanning Electron

The amorphous-nanocrystal Ni-Mo deposits were obtained by electrodeposition in alkaline nickel carbonate solution. X-ray diffraction (XRD), scanning electron microscopy (SEM) and modern technologies were used to describe the content, microstructure and morphology of the deposits. The electrochemical characteristics of Ni-Mo deposits were electrolyzed in 33°C, 7 mol/L NaOH electrolytic solutions. The results showed that when I was 100 mA·cm−2, the hydrogen evolution potential of Ni-Mo21.76 was lower than amorphous Ni-Mo26.36 and 250mV lower than the nanocrystal Ni cathode. And the Ni-Mo deposits with more amorphous phase content would be in lower hydrogen evolution overpotential, a higher exchange current density, and a better electrolytic stability. These due to the amorphous combined with nanocrystal, lager contact surface and binding energy of Ni-Mo structure.

scholarly journals The influence of substituted aromatic aldehydes on Zn-Mn alloy electrodeposition

2013 ◽  
Vol 78 (10) ◽  
pp. 1569-1581 ◽  
Author(s):  
Mihael Bucko ◽  
Uros Lacnjevac ◽  
Jelena Bajat
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Evolution ◽  
High Current Density ◽  
Aromatic Aldehydes ◽  
High Current ◽  
X Ray ◽  
Alloy Electrodeposition ◽  
Additive Type ◽  
Scanning Electron

Additives are necessary in the electrodeposition of Zn-Mn alloys at high current density, in order to reduce hydrogen evolution reaction and prevent dendrite formation. The influence of two aromatic aldehydes, 4-hydroxy-benzaldehyde and 3,4-dimethoxy-benzaldehyde, as the additives in Zn-Mn plating electrolyte, is examined in this work. The coatings characterization by scanning electron microscopy and X-ray energy dispersive spectroscopy, as well as the examination of additives effect by electrochemical methods, indicate a complex involvement of additive molecules in hydrogen evolution, as well as in Zn2+ and Mn2+ reduction. Consequently, the levelling action can be achieved and the chemical composition of the Zn-Mn alloy can be tailored, by adding the proper additive type and concentration in the plating electrolyte.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Scanning Electron Microscopy and X-Ray Analyses of Dental Tissues from a Hibernator

1976 ◽  
Vol 34 ◽  
pp. 178-179
Author(s):  
M. L. Zimny ◽  
A. C. Haller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Temperature ◽  
Ground Squirrel ◽  
Alveolar Bone ◽  
X Ray ◽  
Dental Tissues ◽  
Bone Minerals ◽  
Apical Tooth ◽  
Scanning Electron

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

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