Line Profile Analyses of Rhodium Metal Obtained by Decomposition of Rhodium Carbonyl

1994 ◽  
Vol 38 ◽  
pp. 413-425
Author(s):  
Dhanesh Chandra ◽  
Himanshu Mandalia ◽  
Michael L. Garner ◽  
Mary Kay Blakely ◽  
K. H. Lau
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Metal Carbonyl ◽  
High Surface Area ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Integral Breadth ◽  
Metallic Particles ◽  
Lattice Strains ◽  
Potential Applications

Abstract Metal carbonyls are important for chemical vapor deposition (CVD) of metals and alloys and formation of high surface area metallic particles which have potential applications as catalysts. Rhodium carbonyl [Rh6(CO)16] produces high surface area metallic particles whose structure has been reported as monoclinic (I2/a) with lattice dimensions, a=17.00(±0.03)Å, b=9.78(±0.02)Å, c=17.53(±0.03)Å and β=121°45' ± 30' at room temperature. Generally, metal carbonyl crystals dissociate under vacuum as carbonyl gas and decompose to metallic crystals and carbon monoxide at higher temperatures. However, the behavior of rhodium carbonyl crystals is different; they decompose directly to metallic rhodium without the formation of rhodium carbonyl gas in vacuum. Several residual fine grains of rhodium metal are found after the decomposition in vacuum at relatively low temperatures. The metallic samples of rhodium were obtained from vapor pressure experiments using torsion Knudsen-effusion apparatus. X-ray diffraction analyses performed on these grains showed severely broadened Bragg reflections indicative of small particle size and/or lattice microstrain. In this study, a comparison of lattice strains and domain sizes obtained by integral breadth and Fourier methods has been made. In addition a comparison of the lattice strains and domain sizes has been made between the Cauchy, Gaussian, Cauchy-Gaussian and Aqua integral breadth methods.

Nanostructured TiO2 Materials: Preparation, Properties and Potential Applications (3P’s)

2017 ◽  
Vol 266 ◽  
pp. 84-89 ◽  
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Khairul Anuar Mat Amin
Keyword(s):  
Surface Area ◽  
Nanostructured Materials ◽  
Food Packaging ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
New Class ◽  
Potential Applications ◽  
High Surface Area Materials

Nanostructured materials are a new class of materials which provide one of the greatest potentials for improving performance and extended capabilities of products in a number of applications. In particular nanostructured TiO2 was used as photocatalysts, gas sensor, solar cells and nanocomposite biomaterials. For each of these applications, aspects such as surface morphology, crystallinity and chemistry of the titania-based materials are the key parameters to be settled for the process optimization. A series of nanostructured TiO2 materials (TiO2 nanotubes, TiO2 nanorods, TiO2 nanoparticles) was synthesized using simple hydrothermal methods. X-Ray Diffraction (XRD), Field Emission Scanning Electron microscope (FESEM) and Brunauer–Emmett–Teller (BET) surface area characterization was carried out to study the properties of synthesized nanostructured TiO2 materials. The performance of synthesized nanostructured TiO2 was evaluated for various applications such as photocatalyst for methyl orange (MO) degradation and anti-bacterial thin film for biomedical and food packaging. Among the nanostructured TiO2 materials, TiO2 nanotubes shows the highest activity regardless of their applications. This is probably due to their nanotubular morphology in which provided high surface area materials. The surface area of TiO2 nanotubes was found to be 226.52 m2/g. The outer and inner diameters of nanotubes are 4 nm and 10 nm, respectively with several hundred nanometers in length. Anatase TiO2 phase structure and crystallinity of TiO2 nanotubes supports the good performances of the nanostructured materials.

Preparation, Characterization and Photocatalytic Properties of Flower Like Bi2WO6 under Solar Light Irradiation

2010 ◽  
Vol 148-149 ◽  
pp. 1656-1660
Author(s):  
Jian Hui Sun ◽  
Jing Lan Feng ◽  
Xiao Ke Tian ◽  
Sun Ying Dong
Keyword(s):  
Surface Area ◽  
Model Compound ◽  
High Surface ◽  
High Surface Area ◽  
Light Irradiation ◽  
Solar Light ◽  
X Ray Diffraction ◽  
Solar Light Irradiation ◽  
Decolorization Efficiency ◽  
Method Analysis

Flower like Bi2WO6 powders were synthesized via a mild hydrothermal method. Analysis of X-ray diffraction (XRD) revealed that optimal calcination temperature was believed to be 400 °C at which the photocatalyst displayed high surface area and small crystallite size. Scanning electron microscope (SEM) showed that obtained Bi2WO6 with a flower like shape, which greatly enhance the surface area of catalyst and increase the contact area with dyes. The photocatalytic activity of as-prepared catalyst was investigated using Rhodamine B as a model compound under solar light irradiation. Results showed that the prepared photocatalyst was an effective photocatalyst and exhibited high photocatalytic performance. In the presence of 1 g/L Bi2WO6, 80.76% decolorization efficiency of RhB could be achived after 150 min irradiation

Doping of Palladium in Silica Nanofibers via Electrospinning and Sol-Gel Synthesize as Hydrogen Storage Material

2011 ◽  
Vol 471-472 ◽  
pp. 1040-1045 ◽  
Author(s):  
Samaneh Shahgaldi ◽  
Zahira Yaakob ◽  
Dariush Jafar Khadem ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
High Surface Area ◽  
Chemical Vapour ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Silica Nanofibers

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.

High Surface Area Flexible Chemiresistive Biosensor by Oxidative Chemical Vapor Deposition

2011 ◽  
Vol 21 (22) ◽  
pp. 4328-4337 ◽  
Author(s):  
Dhiman Bhattacharyya ◽  
Kris Senecal ◽  
Patrick Marek ◽  
Andre Senecal ◽  
Karen K. Gleason
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Area ◽  
Vapor Deposition ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Vapor

Synthesis and Analysis of High Surface Area Vanadium Carbide Nanoparticles

2012 ◽  
Vol 585 ◽  
pp. 95-99 ◽  
Author(s):  
M. Mahajan ◽  
K. Singh ◽  
O.P. Pandey
Keyword(s):  
Surface Area ◽  
Vanadium Carbide ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
X Ray ◽  
Transmission Electron ◽  
Product Powder ◽  
Scanning Electron

Vanadium carbide is known for its applications due to extreme hardness and high melting point. In this present work, vanadium carbide nanoparticles have been synthesized in a specially designed stainless steel autoclave by solvothermal route using vanadium pentoxide (V2O5) as precursor along with a hydrocarbon acetone (C3H6O) in the presence of reducing agent magnesium (Mg). The optimization of reaction time was studied at constant temperature of 800oC. The product powder was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and Brunauer – Emmett – Teller (BET) techniques. The results indicate that the product was vanadium carbide having particle size of about 30 nm with high surface area.

scholarly journals Synthesis of Wollastonite Powders by Combustion Method: Role of Amount of Fuel

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Imarally V. de S. R. Nascimento ◽  
Willams T. Barbosa ◽  
Raúl G. Carrodeguas ◽  
Marcus V. L. Fook ◽  
Miguel A. Rodríguez
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Combustion Process ◽  
Calcium Nitrate ◽  
Combustion Method ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Solution Combustion

The objective of this work has been the synthesis of wollastonite by solution combustion method. The novelty of this work has been obtaining the crystalline phase without the need of thermal treatments after the synthesis. For this purpose, urea was used as fuel. Calcium nitrate was selected as a source of calcium and colloidal silica served as a source of silicon. The effect of the amount of fuel on the combustion process was investigated. Temperature of the combustion reaction was followed by digital pyrometry. The obtained products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and specific surface area. The results showed that the combustion synthesis provides nanostructured powders characterized by a high surface area. When excess of urea was used, wollastonite-2M was obtained with a submicronic structure.

scholarly journals Preparation of Ammonia Dealuminated Metakaolinite and Its Adsorption against Bixin

2020 ◽  
Vol 20 (4) ◽  
pp. 791
Author(s):  
Winda Rahmalia ◽  
Jean-Francois Fabre ◽  
Thamrin Usman ◽  
Zéphirin Mouloungui
Keyword(s):  
Surface Area ◽  
Room Temperature ◽  
High Surface ◽  
High Surface Area ◽  
Total Pore Volume ◽  
Adsorption Properties ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order

This study aims to prepare dealuminated metakaolinite which has a high surface area by using NH4OH as an activator. The natural kaolinite sample was treated at 600 °C for 6 h in order to obtain metakaolinite. A dealuminated metakaolinite was then prepared by the repeated activation method using concentrated ammonia (5 M NH4OH) at room temperature. Depending on the nature of each type of material, natural kaolinite, NH4OH treated kaolinite, metakaolinite and NH4OH treated metakaolinite were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET-N2) measurements. XRD and FTIR results confirmed that structural transformation from kaolinite to metakaolinite had occurred. According to SEM-EDS data, the activation of metakaolinite by NH4OH allowed the dealumination of metakaolinite. The increase in the Si/Al ratio was almost twice as high as in kaolinite. BET-N2 analysis showed that the specific surface area and the total pore volume increased significantly after activation. Its adsorption properties were tested against bixin. Bixin adsorption on dealuminated metakaolinite followed pseudo-second order kinetic where k2 = 0.20 g/mg min. The adsorption isotherm followed the Langmuir model where qm = 0.72 mg/g.

Potential applications of a small high-surface-area platinum electrode as an implanted impedance biosensor or recording electrode

2001 ◽  
Author(s):  
Yvonne Y. Duan ◽  
Rodney E. Millard ◽  
Michael Tykocinski ◽  
Xuguang Lui ◽  
Graeme M. Clark ◽  
...  
Keyword(s):  
Surface Area ◽  
Platinum Electrode ◽  
High Surface ◽  
High Surface Area ◽  
Recording Electrode ◽  
Potential Applications
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