Morphological Characterization of Shape-Controlled TiO2 Anatase through XRPD Analysis

2016 ◽  
Vol 230 (9) ◽  
Author(s):  
Mauro Coduri ◽  
Michela Maisano ◽  
Maria Vittoria Dozzi ◽  
Elena Selli

AbstractPreferential growth of anatase crystallites along different directions is known to deeply affect their photocatalytic properties, especially with respect to the exposure of the reactive {001} facets. Its extent can be easily quantified through simple geometric calculations, on the basis of crystal sizes extracted for specific directions by means of X-Ray Diffraction data analysis. Nevertheless, the actual results depend on the method employed for such a quantification. Here we report on a comparative morphological investigation, performed by employing the Scherrer equation and the line profile from Rietveld refinements, on shape-controlled anatase photocatalysts produced by employing HF as capping agent. Compared to the Rietveld-based method, the use of the Scherrer equation produces a systematic underestimation of crystallite dimensions, especially concerning the [100] direction, which in turn causes the percentage of exposed {001} crystal facets to be underestimated. Neglecting instrumental-related effects may further reduce the estimate.

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.


DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 278-287
Author(s):  
Javier Alberto Olarte Torres ◽  
María Cristina Cifuentes Arcila ◽  
Harvey Andrés Suárez Moreno

This paper presents the results obtained from the synthesis and morphological characterization of different magnetite samples:  La0.67-x Prx Ca0.33 MnO3.LaMn1-x Cox O3 and LaMn1-x Nix O3 at 0.13 ≤ 𝑥𝑥 ≤ 0.67 produced by a solid-state reaction mechanism and 𝐿𝐿𝐿𝐿𝑀𝑀𝑀𝑀1−𝑥𝑥(𝐶𝐶𝐶𝐶/𝑁𝑁𝑁𝑁)𝑥𝑥𝑂𝑂3 at 0.0 ≤ 𝑥𝑥 ≤ 0.5 produced by the sol-gel method. These samples were characterized using X-ray diffraction spectroscopy and by measuring electric resistivity and magnetic susceptibility which were carried out as a function of temperature. Notably, the effects of strain and compressive strength on the lattices of magnetite samples were highly dependent on the concentration of 𝑃𝑃𝑟𝑟, 𝐶𝐶𝐶𝐶, and 𝑁𝑁𝑁𝑁. Moreover, the transition temperatures of metal-insulator and ferromagnetic-paramagnetic phases also largely depend on these strength effects, e.g., at higher concentrations of 𝑃𝑃𝑟𝑟, effects of increased strain strength were observed, relocating the shifts of ferromagnetic-paramagnetic transitions to lower temperatures. On the other hand, effects of increased compressive strength were observed at higher concentrations of 𝑁𝑁𝑁𝑁 and 𝐶𝐶𝐶𝐶, relocating the shifts of ferromagnetic-paramagnetic and metal-insulator transitions to higher temperatures.


Cerâmica ◽  
2007 ◽  
Vol 53 (328) ◽  
pp. 422-447
Author(s):  
F. C. D. Lemos ◽  
D. M. A. Melo ◽  
P. S. de Lima ◽  
C. A. Paskocimas ◽  
E. Longo ◽  
...  

Rare earth modified lead titanate powders Pb1-xRExTiO3 (REPT), x = 0.01, 0.05, 0.07 and RE = Yb, Y, were prepared by the Pechini method. The materials were calcined under flowing oxygen at different temperatures from 300 to 700 ºC. Nanostructured REPT were investigated using X-ray diffraction, scanning electron microscopy and surface area analysis (BET). The results suggest that the modifier cation incorporated into the system has notable influence in the microstructure and a notable decrease in the crystallite sizes.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Alvaro Ruíz-Baltazar ◽  
Rodrigo Esparza ◽  
Maykel Gonzalez ◽  
Gerardo Rosas ◽  
Ramiro Pérez

This study is aimed at investigating the structural and morphological characterization of natural and modified zeolite obtained from the state of Oaxaca (Mexico). Iron nanoparticles were used for the zeolite modification. The iron nanoparticles were loaded on the zeolite surface by homogeneous nucleation. Adsorption kinetic models of pseudo first and second order were surveyed. The characterization of pristine and modified zeolite was performed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). From the results, three main phases were identified: clinoptilolite, mordenite, and feldspar. We could also determine the adsorption capacity of the zeolites by means of adsorption kinetic models.


2008 ◽  
Vol 47-50 ◽  
pp. 903-906
Author(s):  
Li Fei Chen ◽  
Hua Qing Xie ◽  
Yang Li ◽  
Wei Yu

Copper sulfide (CuS) nanocrystals with flower-like and tubular morphology have been successfully synthesized via a facile and convenient hydrothermal route at 75 °C by using CuCl2·2H2O as Cu-precursor, C2H5NS as S-source and CTAB as template molecules. The effect of concentration of reactants and template molecules on morphology has been discussed. X-ray diffraction pattern suggests that the CuS crystals are pure hexagonal phase. The morphology of the products has been studied by scanning electron microscope analysis. The absorption peaks of CuS in UV and near-IR regions indicate that the as-prepared CuS are promising in the development of photoelectric devices.


Mining Revue ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 78-82
Author(s):  
Nurudeen Salahudeen ◽  
Aminat Oluwafisayo Abodunrin

Abstract Local clay mineral was mined from Okpella Town, Etsako Local Government Area of Edo State, Nigeria. Mineralogical characterization of the clay was carried out using X-ray diffraction analyzer. Chemical characterization of the clay was carried out using X-ray fluorescence analyzer and the pH analysis of the clay was carried out using pH meter. The mineralogical analysis revealed that the clay was majorly a dolomite mineral having 72% dolomite. The impurities present are 18% cristobalite, 4.1% garnet, 5% calcite and 1% quicklime. The pH analysis of the clay revealed that the clay was acidic having average pH value of 3.9. The pH determined for the 1:1, 1:2, 1:4, 1:8 and 1:10 samples were 3.61, 3.85, 3.85, 4.05 and 4.09, respectively.


2011 ◽  
Vol 264-265 ◽  
pp. 530-534
Author(s):  
M.M. Alam ◽  
M. Harun ◽  
Momtazul Islam

Silver nanoparticles protected by Tetradecyltrimethyl Ammonium Bromide (TTAB) were prepared in a one-phase electrochemical system. Electrochemical procedure, based on the dissolution of a metallic anode in an appropriate solvent, has been used to get silver nanoparticles. It is possible to get different particle size by changing the current density. The optical properties of the silver Nanoparticles were investigated by UV-Vis and Photoluminescence (PL) Spectroscopy. Absorption peak were found 424 nm which confirm the presence of Ag nanoparticles. The structural properties of the samples were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. XRD confirmed the preferential growth of Ag nanoparticles whose average size is ≈ 20 nm in the <111> orientation as well as purity of silver clusters.


2010 ◽  
Vol 657 ◽  
pp. 62-74 ◽  
Author(s):  
Rajesh J. Tayade ◽  
D.L. Key

TiO2 derived nanotubes were prepared by hydrothermal treatment of TiO2 (anatase) powder in 10 M NaOH aqueous solution. The crystalline structure, band gap, and morphology of the TiO2 nanotubes were determined by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Transmission Electron microscopy (TEM) and N2 adsorption (BET) at 77 K, respectively. It was observed that the surface area of the nanotubes was increased twelve times compared with TiO2 (anatase) powder. The results demonstrated that the photocatalytic activity of TiO2 nanotubes was higher than that of TiO2 (anatase) powder. The photocatalytic activity of the nanotubes was evaluated in presence of sunlight by degradation of aqueous nitrobenzene. Complete degradation of nitrobenzene was obtained in 4 hours using TiO2 nanotubes whereas 85% degradation was observed in case of TiO2 (anatase).


2012 ◽  
Vol 482-484 ◽  
pp. 2555-2558
Author(s):  
Hong Mei Wang ◽  
Yuan Lian

Hexagonal ZnS nanostructured spheres self-assembled from ZnS nanocrystals were successfully synthesized through a facile hydrothermal method using 1-butyl-3-methlyimidazole thiocyanate ([BMIM][SCN]) as both sulfur source and capping ligand. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), ultraviolet–visible (UV–vis) absorption spectra, a structural and morphological characterization of the products was performed. The photocatalytic activity of ZnS microspheres had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial ZnS powders, which indicated that the as-syntherized ZnS spheres exhibited enhanced photocatalytic activity for degradation of RB.


2020 ◽  
Author(s):  
Tika Ram Bhandari ◽  
Bidit Lamsal ◽  
Prasamsha Panta ◽  
Nilam Shrestha Pradhan ◽  
Marco Liebscher ◽  
...  

Abstract BackgroundCrinis Carbonisatus, prepared by pyrolysis of human hair, is traditional Chinese medicine used for increasing blood clotting and wound healing. Its use is explored in literature but no detailed structural study is reported.ObjectiveThis work is aimed at studying the chemical and morphological variation of Crinis Carbonisatus under given heating condition.Materials and methodsCrinis Carbonisatus was obtained after pyrolysis of human hair at 300 °C in sealed ceramic pot. The obtained samples were characterized in terms of its physicochemical properties by scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and X-ray Diffraction (XRD). ResultsDistinct morphology with nano-particulate structure was observed on SEM micrographs. FTIR spectroscopy of the samples revealed the presence of functional groups like –OH, -COO-­, -NH as well as methyl (-CH3) and methylene (-CH2­-) groups. Graphite interlayer spacing peak appeared in XRD pattern only after 24 h of pyrolysis.ConclusionPyrolysis converts the micron sized particles into the nanometric entities. Amorphous behavior of the materials decreases with the increase in pyrolysis time.


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