Bifunctional Electrocatalytic Films with Gold Nanoparticles and Metalloporphyrin: Preparation and Characterization

2001 ◽  
Vol 676 ◽  
Author(s):  
Wenjun Yang ◽  
Xiaoyuan Li ◽  
Nai-Teng Yu

ABSTRACTBifunctional electrocatalytic films were prepared employing a layer-by-layer assembly approach. The cation, metalloporphyrin (MP), and the anion, potassium tetrachloroaurate (KAuCl4) were alternatively assembled on glass or indium-doped tin oxide (ITO) supports. The assembled AuCl4- ions were then converted to gold nanoparticles (Aun) under the exposure to ultraviolet light. Film growth at each adsorption step was monitored by UV-Vis absorption spectroscopy and cyclic voltammetry (CV). The formation of gold nanoparticles was characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Bifunctional electrocatalytic activity of the film was demonstrated in the oxidative detection of nitric oxide (NO) over Aun and the reductive detection of oxygen (O2) over Co(II)P in the same CV scan.

1992 ◽  
Vol 271 ◽  
Author(s):  
Isao Yag ◽  
Shoji Kaneko

ABSTRACTTin oxide films were grown from di-n-butyltin diacetate on a heated glass substrate by a pneumatic spraying system The effects of various film growth parameters. i.e solvent, solution feed rate, film thickness, and film growth rate on the microstructures of the films were studied by X-ray diffraction and scanning electron microscopy The SnO2 films of the (200) plane were grown by the optimum growth parameters


2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.


2000 ◽  
Vol 15 (10) ◽  
pp. 2076-2079
Author(s):  
Chika Nozaki ◽  
Takashi Yamada ◽  
Kenji Tabata ◽  
Eiji Suzuki

Synthesis of a rutile-type lead-substituted tin oxide with (110) face was investigated. The characterization was performed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area measurements. The homogeneous rutile-type lead-substituted tin oxide was obtained until 4.1 mol% of tin was substituted with lead. The surface of obtained oxide had a homogeneously lead-substituted (110) face.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiwoong Heo ◽  
Daheui Choi ◽  
Jinkee Hong

We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4) nanoparticles, using layer-by-layer (LbL) self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1) a blended three-component LbL film consisting of a sequential poly(acrylic acid)/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride) layer and (2) a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride), poly(sodium-4-sulfonate), bPEI-ferrite, and poly(sodium-4-sulfonate) layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4) were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.


2015 ◽  
Vol 60 (2) ◽  
pp. 1165-1167
Author(s):  
Ri Yu ◽  
Juyeon Yun ◽  
Jae-Hwan Pee ◽  
Yoojin Kim

Abstract This work describes the design of bi-functional α-Fe2O3/Zn2SiO4:Mn2+ using a two-step coating process. We propose a combination of pigments (α-Fe2O3) and phosphor (Zn2SiO4:Mn2+) glaze which is assembled using a layer-by-layer method. A silica-coated α-Fe2O3 pigment was obtained by a sol-gel method and a Zn2+ precursor was then added to the silica-coated α-Fe2O3 to create a ZnO layer. Finally, the Zn2SiO4:Mn2+ layer was prepared with the addition of Mn2+ ions to serve as a phosphor precursor in the multi-coated α-Fe2O3, followed by annealing at a temperature above 1000°C. Details of the phase structure, color and optical properties of the multi-functional α-Fe2O3/Zn2SiO4:Mn2+ were characterized by transmission electron microscopy and X-ray diffraction analyses.


2015 ◽  
Vol 1731 ◽  
Author(s):  
Carlo Requião da Cunha ◽  
Fábio Dias da Silva ◽  
Renzo Morales

ABSTRACTTin oxide aerogels were synthesized using the epoxide-assisted technique and characterized with X-ray diffraction, diffusive reflectance spectroscopy, particle-induced X-ray emission and scanning electron microscopy. Our results indicate that the material is electrically semi-insulating as the result of oxygen vacancies that appear as fixed charges at the bottom of the conduction band. A modification of the technique with the addition of hydrogen peroxide is proposed to reduce the levels of defects and enhance the optical transparency of the material.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

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.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

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.


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.


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