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.

scholarly journals The Phase and Morphology of Cu2ZnSnSe4Nanopowders by Hydrothermal Method

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Kegao Liu ◽  
Nianjing Ji ◽  
Ludan Shi ◽  
Hong Liu
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Quaternary Compound ◽  
Metal Chlorides ◽  
X Ray ◽  
Rare Elements ◽  
Size And Morphology ◽  
Absorbing Layer ◽  
Scanning Electron

Quaternary compound Cu2ZnSnSe4(CTZSe) which belonged to I2-II-IV-VI4group, without rare elements, can be considered as the perfect material for absorbing layer in eco-friendly solar cells due to low cost and high efficiency. The CTZSe powders were synthesized by hydrothermal coreduction method from metal chlorides and SeO2with reducing agent hydrazine hydrate at 160~200°C. The phases of obtained products were analyzed by X-ray diffraction (XRD) and the size and morphology were observed by field emission scanning electron microscope (FESEM). Experimental results show that well crystallized Cu2ZnSnSe4powders without Se impurities can be obtained by reacting at 200°C for 90 h. The three strong XRD peaks of these products are corresponding to (112), (204), and (312) crystal planes, respectively. The morphologies of these products mostly show irregular polygon flakes with about 30~40 nm thickness and 50~200 nm diameters.

scholarly journals Calcium pyrophosphate powder derived from avian eggshell waste

Cerâmica ◽  
2016 ◽  
Vol 62 (363) ◽  
pp. 278-280 ◽  
Author(s):  
T. H. A. Corrêa ◽  
J. N. F. Holanda
Keyword(s):  
Electron Microscopy ◽  
Low Cost ◽  
Average Crystallite Size ◽  
Calcium Pyrophosphate ◽  
Precipitation Method ◽  
Medical Applications ◽  
X Ray Diffraction ◽  
X Ray ◽  
Eggshell Waste ◽  
Scanning Electron

Abstract Calcium pyrophosphate (CPP) was prepared by a simple precipitation method using avian eggshell waste as a low-cost alternative calcium precursor source. The synthesized CPP powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The results indicate that pure β-CPP nanocrystallites (Ca/P = 1.067) were successfully synthesized from avian eggshell waste. The correlation among XRD, SEM/EDS, TGA, and FTIR data is well established. The β-CPP particle exhibited spherical morphology with average crystallite size of 62.3 nm, and can be an important bioceramic for medical applications.

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.

scholarly journals Synthesis of ZnO-CdO Nanocomposites

2013 ◽  
Vol 1 (1) ◽  
pp. 11-14
Author(s):  
N. Sahu ◽  
◽  
R. K. Duchaniya ◽  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Low Cost ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Synthesis Process ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The ZnO-CdO nanocomposite was prepared by sol-gel method by using their respective nitrates. It is a simple and low cost method to prepare nanocomposites. The drying temperature and drying period of prepared gel was varied during the synthesis process. The prepared samples were characterized by using scanning electron microscope (SEM), particle size analysis (PSA), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to get surface morphology, idea of getting particle of nanosized range so that further characterizations can be done, to study the optical property of synthesized nanocomposite and measure the band gap . The grain size determined by Scherrer’s formula was found to be between 30-50 nm.

Preparation and Electrochemical Properties of Nano Si-C Composite

2016 ◽  
Vol 852 ◽  
pp. 278-282
Author(s):  
Xiao Chen ◽  
Yun Yang ◽  
Shui Jin Yang ◽  
Chuan Qi Feng ◽  
Zai Ping Guo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Current Density ◽  
Reversible Capacity ◽  
Testing System ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Capacity ◽  
Scanning Electron

nanoSi-C composite was prepared using eletronspinning technique. The microstructure and morphology of the Si-C composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performances of the Si-C composite were tested by battery testing system. The results showed that the Si-C composite not only behaved high initial capacity but also good cycle performances. The reversible discharge capacity could remain at 860 mAhg-1 when current density was 50 mAg-1. The rate reversible capacity is much higher than that of pure nanoSi anode at same condition.

Influence of Composition and Isothermal Sintering on the Properties of Hydroxyapatite Bioceramic Bodies

2014 ◽  
Vol 979 ◽  
pp. 347-350
Author(s):  
Rungsarit Koonawoot ◽  
Cherdsak Saelee ◽  
Sakdiphon Thiensem ◽  
Sittiporn Punyanitya
Keyword(s):  
High Efficiency ◽  
Bending Strength ◽  
Strength Properties ◽  
Raw Material ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This work reports the influence of chemical composition and sintering schedule on the properties of sintered bodies of hydroxyapatite (HA) bioceramic. The method of preparing sintered bodies by solid state reaction and uniaxial pressing. The raw material used calcium carbonate (CaCO3) and ammonium dihydrogen phosphate (NH4H2PO4) powder as precursors. These powders were mixed at CaCO3: NH4H2PO4 mass ratio of 1:0.697, 1:0.692, 1:0.689, 1:0.685 and 1:0.68, respectively. The compositions in the temperatures range of 800-1300 °C for 3 hour. The sintered bodies were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Properties including phase, microstructures, porosity and bending strength of the samples. The results show that green bodies can be sintered at 1150 °C for 3 hours. This temperature found that crystals growth, highest of HA phase content in sintered bodies, good density and high efficiency strength properties.

Effects of NaBH4 Additions on Hydrogen Absorption by Nanostructured FeTi Powders

2008 ◽  
Vol 587-588 ◽  
pp. 921-925 ◽  
Author(s):  
Sofia F. Marques ◽  
Raquel A. Silva ◽  
Jose Brito Correia ◽  
Nobumitsu Shohoji ◽  
Carmen M. Rangel
Keyword(s):  
Hydrogen Absorption ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Low Cost ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Atmosphere ◽  
Scanning Electron

FeTi intermetallic powders are very promising media for reversible hydrogen storage. However, difficult activation treatments including annealing at elevated temperatures in high pressure H2 gas atmosphere are mandatory. In the present work nanostructured FeTi powders were produced and activated in situ at room temperature using mechanical alloying/milling (MA/MM) of pure metallic constituents, Fe and Ti, added with sodium borohydride. The resultant powders, FeTiHx, already H2 pre-charged, absorbed a significant amount of H2 but require optimization for reversible absorption/desorption. This system has one of the highest volumetric storage capacities and can be produced at low cost. Several parameters of the as-milled powders were controlled. The phase constitution of the reaction products was characterized by X-ray diffraction and scanning electron microscopy and the absorption isotherms of the activated powders were determined.

Effects of Bath Composition and P Contents on the Mechanical Properties of Ni-P Electroplating

2020 ◽  
Vol 12 (4) ◽  
pp. 605-608
Author(s):  
Hong-Uk Cheon ◽  
Jae-Ho Lee
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Copper Substrate ◽  
Surface Hardness ◽  
Phosphorous Acid ◽  
Bath Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfate Bath ◽  
Scanning Electron

Ni-P alloys are fabricated on the pre-cleaned copper substrate using electroplating method in sulfate bath. The concentration of phosphorous acid and current density were varied to optimize the P contents as well as the physical properties of the alloy. The properties of Ni-P alloy were analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The surface hardness of the Ni-P alloy was increased up to 550 Hv as the phosphorous acid (H3PO3) increased upto 0.015 M, however the higher phosphorous contents in the coating developed the cracked on the surface. The surface hardness was increased due the grain refinement.

Temperature Effect on the Thermoluminescent Signal Induced by Gamma Radiation in NaCl

2015 ◽  
Vol 1769 ◽  
Author(s):  
Demetrio Mendoza Anaya ◽  
Pedro R. González Martínez ◽  
María E. Fernández García ◽  
Gilberto Mondragón Galicia ◽  
Claudia E. Gutiérrez Wing
Keyword(s):  
Electron Microscopy ◽  
Gamma Radiation ◽  
Gamma Ray ◽  
Irradiation Time ◽  
Low Cost ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Linear Dependency ◽  
Scanning Electron

ABSTRACTThe effects of thermal treatments on the thermoluminescent (TL) signal of NaCl (ACS reagent) induced by gamma radiation were investigated. Samples of NaCl were thermally treated at 500, 800 and 1000 °C and characterized by X-Ray diffraction and scanning electron microscopy. After their exposure 0.1 to 150 Gy of gamma radiation from a gamma-ray source of 60Co, a TL curve for each temperature of treatment was obtained. We observed a different TL behavior on the irradiated samples as a function of the temperature applied during the thermal treatments. For the sample treated at 500 °C, three peaks centered at 102, 133 and 228 °C were observed. Samples treated at 800 and 1000 °C showed two main peaks at 128 and 220 °C and 136 and 219 °C, respectively; however, the highest TL intensity signal was observed for the sample at 800 °C. All samples showed a linear dependency of the integrated TL intensity from the signal emitted as function of the irradiation time. This is an important advantage because NaCl could be applied as a very low cost thermoluminescent dosimetric material. A comparison between the TL signal induced by gamma radiation in pure and Eu doped NaCl is also reported.

Preparation and Characterization of Cement-TiO2 Composites

2015 ◽  
Vol 804 ◽  
pp. 133-136
Author(s):  
Noosara Kaewgabkam ◽  
Nittaya Jaitanong ◽  
Suparut Narksitipan
Keyword(s):  
Composite System ◽  
Low Cost ◽  
High Photocatalytic Activity ◽  
Chemical Compositions ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Content ◽  
Scanning Electron

Titanium dioxide (TiO2) is the most widely used photocatalyst because of its high photocatalytic activity and reasonably low cost. Moreover, TiO2 has strong chemical stability in a large variety of environmental conditions. The combination of TiO2 with cementatious materials has been widely investigated, and the effects of the TiO2 contents (10-40% by weight) were studied in this research. The crystalline structures and chemical compositions were analyzed using x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS), respectively. Moreover, its microstructure was investigated by scanning electron microscopy (SEM). It was found that the intensity of CS and CH decreased with an increase in the TiO2 powder content. This was because when adding more TiO2 powder to the composite system, more water was needed to add to the hydration reaction.

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