scholarly journals Interlayer-Confined Cu(II) Complex as an Efficient and Long-Lasting Catalyst for Oxidation of H2S on Montmorillonite

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 510
Author(s):  
Elena Castellini ◽  
Fabrizio Bernini ◽  
Lorenzo Sebastianelli ◽  
Claro Ignacio Sainz-Díaz ◽  
Aida Serrano ◽  
...  
Keyword(s):  
High Efficiency ◽  
Catalytic Mechanism ◽  
Atmospheric Oxygen ◽  
Low Cost ◽  
H2s Removal ◽  
X Ray ◽  
S 100 ◽  
Long Time ◽  
Phenanthroline Complex ◽  
X Ray Absorption

Removal of highly toxic H2S for pollution control and operational safety is a pressing need. For this purpose, a montmorillonite intercalated with Cu(II)-phenanthroline complex [Cu[(Phen)(H2O)2]2+ (Mt-CuPhen) was prepared to capture gaseous H2S under mild conditions. This hybrid material was simple to obtain and demonstrated an outstanding ability to entrap H2S at room temperature, retaining high efficiency for a very long time (up to 36.8 g of S/100 g Mt-CuPhen after 3 months of exposure). Sorbent and H2S uptake were investigated by elemental analysis, X-ray powder diffraction measurements, diffuse reflectance (DR) UV–Vis and infrared spectroscopy, thermal analysis and evolved gas mass spectrometry, scanning electron microscopy equipped with energy-dispersive X-ray spectrometer, and X-ray absorption spectroscopy. The H2S capture was studied over time and a mechanism of action was proposed. The entrapping involves a catalytic mechanism in which [Cu[(Phen)(H2O)2]2+ acts as catalyst for H2S oxidation to S0 by atmospheric oxygen. The low cost and the long-lasting performance for H2S removal render Mt-CuPhen an extremely appealing trap for H2S removal and a promising material for many technological applications.

scholarly journals Exploring the effect of Ni/Cr contents on the sheet-like NiCr-oxide-decorated CNT composites as highly active and stable catalysts for urea electrooxidation

Clean Energy ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 58-66
Author(s):  
Qiuping Gan ◽  
Benzhi Wang ◽  
Judan Chen ◽  
Jianniao Tian ◽  
Tayirjan Taylor Isimjan ◽  
...  
Keyword(s):  
Surface Area ◽  
Current Density ◽  
High Efficiency ◽  
Catalytic Mechanism ◽  
Low Cost ◽  
Scale Up ◽  
Active Surface ◽  
Environmental Crisis ◽  
Active Surface Area ◽  
Defect Sites

Abstract The developing high-efficiency urea fuel cells have an irreplaceable role in solving the increasingly severe environmental crisis and energy shortages. The sluggish six-electron dynamic anodic oxidation reaction is the bottleneck of the rapid progress of urea fuel-cell technology. To tackle this challenge, we select the NiCr bimetallic system due to the unique synergic effect between the Ni and the Cr. Moreover, better conductivity is assured using carbon nanotubes (CNTs) as the support. Most importantly, we use a simple hydrothermal method in catalyst preparation for easy scale-up at a low cost. The results show that the hybrid catalysts of NiCrx-oxide-CNTs with different Ni/Cr ratios show much better catalytic performance in terms of active surface area and current density as compared to that of Ni-hydro-CNTs. The optimized NiCr2-oxide-CNTs catalyst exhibits not only the largest electrochemically active surface area (ESA, 50.7 m2 g−1) and the highest urea electrocatalytic current density (115.6 mA cm−2), but also outstanding long-term stability. The prominent performance of the NiCr2-oxide-CNTs catalyst is due to the combined effect of the improved charge transfer between Ni and Cr species, the large ESA, along with an elegant balance between the oxygen-defect sites and hydrophilicity. Moreover, we have proposed a synergistically enhanced urea catalytic mechanism.

scholarly journals X-ray absorption measurements on an ultrasonic spray aerosol

2011 ◽  
Vol 19 (1) ◽  
pp. 126-128 ◽  
Author(s):  
R. Schlaf ◽  
B. Höpfner ◽  
J. Figueroa ◽  
E. Tridas ◽  
E. Welter ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Mass Density ◽  
Low Cost ◽  
Buffer Layers ◽  
Solution Flow ◽  
X Ray ◽  
Simple Implementation ◽  
Good Signal ◽  
X Ray Absorption ◽  
Absorption Measurements

Spray deposition of thin films and coatings is a widely used manufacturing process owing to its low cost, versatility and simple implementation. The objective of the presented experiments was to investigate whether X-ray absorption measurements on solutes carried by aerosols are possible, and what count rates can be achieved depending on solution flow through and the resulting mass density in the interrogation volume. The investigated prototypical spray aerosol was InCl3dissolved in water or ethanol dispersedviaan ultrasonic nebulizer. InCl3spray is essential for the ion layer gas reaction process used for the deposition of In2S3buffer layers for highly efficient chalcopyrite solar cells. The discussed experiments demonstrate that measurements are possible, but that the achievement of good signal-to-noise ratios requires extended sampling times and concentrated solutions.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Rapid Photo-Thermal Chemical Vapor Deposition of Amorphous Carbon From Diiodomethane

1999 ◽  
Vol 593 ◽  
Author(s):  
M. Lindstam ◽  
M. Boman ◽  
K. Piglmayer
Keyword(s):  
Electron Microscopy ◽  
Amorphous Carbon ◽  
High Efficiency ◽  
Low Cost ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Substrate Material ◽  
Halogen Lamp ◽  
X Ray

ABSTRACTA novel approach to deposit amorphous carbon from the precursor CH2I2 at low cost and high efficiency is reported. The combination of thermal and quantum photo effects shows new interesting growth behaviour. The radiation of a halogen-lamp was used to heat the substrate material and to split photolytically the precursor molecules above the substrate surface. The deposition process was investigated as a function of lamp power, gas phase partial pressures and substrate materials. The films were analysed by Raman spectroscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray photon spectroscopy, transmission electron microscopy and atomic force microscopy.

DXS: Differential absorption x-ray spectroscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1738-1739
Author(s):  
Robert M. Fisher
Keyword(s):  
Abrupt Change ◽  
Low Cost ◽  
X Ray ◽  
Cost System ◽  
Routine Work ◽  
Precise Adjustment ◽  
Filter Array ◽  
Filter Thickness ◽  
User Friendly ◽  
X Ray Absorption

X-ray spectrochemical analysis, with either energy-dispersive (EDS) or wavelength-dispersive (WDS) systems, is is used extensively by electron microscopists to determine the chemical composition of selected features in a wide variety of specimens. Several decades of development have yielded efficient and rugged detector crystals and goniometer hardware as well as sophisticated, but user-friendly, software for quantitative chemical and image analysis. Nevertheless an alternative system, based on differential x-ray absorption with "balanced" transmission filters (DXS™) has attractive advantages as a simple, low cost, system for qualitative x-ray microanalysis which does not require liquid nitrogen. Computer processing of intensities obviates the former need for impossibly-precise adjustment of filter thickness. However the filter array must be preset for analysis of the elements that are believed to be present for routine work.DXS analysis is based on the abrupt change in x-ray absorption that occurs between particular elements. This is illustrated by the different mass absorption coefficients for Fe and Cr K radiation for a series of filters in increasing atomic number from Ti to Co as shown in Figure 1 (1,2).

Application of a simple arsenic removal filter in a rural area of Bangladesh

2012 ◽  
Vol 12 (5) ◽  
pp. 658-665 ◽  
Author(s):  
Md Mahmudul Hasan ◽  
Md Shafiquzzaman ◽  
Jun Nakajima ◽  
Quazi Hamidul Bari
Keyword(s):  
Rural Area ◽  
Arsenic Removal ◽  
Low Cost ◽  
Ceramic Filter ◽  
Manufacturing Cost ◽  
X Ray ◽  
Sustained Use ◽  
Actual Field ◽  
Contamination Levels ◽  
X Ray Absorption

A simple and low-cost household-based arsenic (As) removal filter (ARF) was tested under actual field conditions in a rural area of Bangladesh. The ARF consisted of a ceramic filter made of clay soil and rice bran collected on-site, iron netting and iron bacterial sludge liquor. Fifteen ARFs (14 shallow and one deep tubewells) were installed in three villages (five in each area) in the Khulna region (southwestern region of Bangladesh), and their performance was evaluated. More than 60% of ARFs produced effluent with As <50 μg/L (Bangladesh standard level). The effects of Fe and P on As removal were the same as in laboratory experiments. X-ray Absorption Fine Structure (XAFS) analysis showed the adsorption of primarily As(V), with lesser amounts of As(III). Continuous As removal performance was observed over 1 year of ARF use. By introducing a double ARF system, the As removal was significantly enhanced for the region with high As contamination levels. The ARF manufacturing cost was estimated to be US$4–5, which is low and affordable to the rural households of Bangladesh. The ARF, made of locally available materials, had a low cost and minimal maintenance and showed high user acceptance, satisfaction and sustained use.

LOCAL STRUCTURE OF PHOTO-INDUCED PHASES PROBED BY X-RAY ABSORPTION SPECTROSCOPY: PHOTO-INDUCED ANISOTROPY IN CHALCOGENIDE GLASSES

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1721-1730 ◽  
Author(s):  
H. OYANAGI ◽  
A. KOLOBOV ◽  
K. TANAKA
Keyword(s):  
Absorption Spectroscopy ◽  
Local Structure ◽  
Chalcogenide Glasses ◽  
High Efficiency ◽  
Grazing Incidence ◽  
Amorphous Selenium ◽  
Fluorescence Excitation ◽  
Excitation Light ◽  
X Ray ◽  
X Ray Absorption

We describe X-ray absorption spectroscopy (XAS) technique to probe the local structure of photo-induced phase. Photo-induced melting of chalcogenide glass (amorphous selenium, a-Se) was investigated. A grazing-incidence fluorescence excitation and a high efficiency X-ray detector were used to detect a small change of coordination number due to photo-induced transformation. It was shown that photo-induced three-fold coordinated sites are formed upon light irradiation forming cross-linking between selenium chains (photo-induced melting). A simple model is proposed which describes the reorientation of selenium chain perpendicular to the polarization direction of excitation light leading to photo-induced dichroism (anisotropy). Potential of XAS as a local probe of nanoscale structural modifications induced by photo-excitation is clearly demonstrated.

A New Wet-Type Dust Removal and Desulfuration Equipment and its Application in the Ceramic Industries

2012 ◽  
Vol 450-451 ◽  
pp. 1629-1632 ◽  
Author(s):  
Zhi Cheng Huang
Keyword(s):  
Spray Drying ◽  
Ceramic Industry ◽  
High Efficiency ◽  
Low Cost ◽  
Dust Removal ◽  
Practical Significance ◽  
Clean System ◽  
Long Time

A new wet-type dust removal and desulfuration equipment can be used in ceramic industry for spray drying tower. It adopts four ways and seven grades remove dust. A pair of tubes are erected inside and outside its structure; it has self- clean system, and it can keep the ability of dust removal for a long time. Practice has proved that this equipment has the advantages of low cost, easy maintenance, high efficiency and can be secondary desulfurization, it has great practical significance.

scholarly journals Bimetallic Co-Based (CoM, M = Mo, Fe, Mn) Coatings for High-Efficiency Water Splitting

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Jadranka Milikić ◽  
Aldona Balčiūnaitė ◽  
Zita Sukackienė ◽  
Dušan Mladenović ◽  
Diogo M. F. Santos ◽  
...  
Keyword(s):  
Current Density ◽  
Potassium Hydroxide ◽  
Electroless Deposition ◽  
High Efficiency ◽  
Low Cost ◽  
Copper Substrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Current ◽  
Scanning Electron

Bimetallic cobalt (Co)-based coatings were prepared by a facile, fast, and low-cost electroless deposition on a copper substrate (CoFe, CoMn, CoMo) and characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Prepared coatings were thoroughly examined for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution (1 M potassium hydroxide, KOH) and their activity compared to that of Co and Ni coatings. All five coatings showed activity for both reactions, where CoMo and Co showed the highest activity for HER and OER, respectively. Namely, the highest HER current density was recorded at CoMo coating with low overpotential (61 mV) to reach a current density of 10 mA·cm−2. The highest OER current density was recorded at Co coating with a low Tafel slope of 60 mV·dec−1. Furthermore, these coatings proved to be stable under HER and OER polarization conditions.

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