WO3:TiO2 Particle Characterization Obtained by High Energy Milling for Application in Photocatalysis

2016 ◽  
Vol 881 ◽  
pp. 404-409
Author(s):  
Raphael Rodrigues Faleiros ◽  
Tania Regina Giraldi ◽  
Jeferson Almeida Dias ◽  
Vera Lúcia Arantes ◽  
Alfeu Saraiva Ramos ◽  
...  
Keyword(s):  
Industrial Effluents ◽  
High Energy ◽  
Heterogeneous Photocatalysis ◽  
Milling Process ◽  
Particle Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Uv C ◽  
Imminent Risk

Effective ways to treat textile industrial effluents have been studied in attempt to find alternatives to reduce the imminent risk of water resources contamination. The heterogeneous photocatalysis stands out in this scenario working in the organic waste mineralization, such as dyes. The objectives of this study were to investigate the obtaining of fine powders of the WO3:TiO2 (the investigated proportions in this work were 0: 100; 30:70; 50:50; 70:30; 100:0) using the high energy milling technique and to evaluate the photocatalytic efficiency of the Rhodamine B dye in this system. The oxides precursors were characterized by X-ray diffraction, BET and Helium pycnometry. After dry milling for 4 hours, the obtained powders were characterized by X-ray diffraction and tested to the photocatalysis in UV-C. The results indicate that the milling process has a direct influence on the photocatalytic properties of the investigated systems, and that the greater presence of titania in the mixture leads to a greater catalytic effect.

Phase Amorphization during High-Energy Milling of Mixtures of Zirconia with Yttria or Ceria Powders

2005 ◽  
Vol 498-499 ◽  
pp. 331-336 ◽  
Author(s):  
R. Muccillo ◽  
L. Franchi ◽  
J.T. Santos ◽  
I.C. Cosentino ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Barium Carbonate ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Transmission Electron ◽  
Strontium Ferrites

Strontium ferrites powders were obtained by high energy milling process after calcinations of iron oxide and barium carbonate. Phase formations and crystallite size was determined using X-ray diffraction. Morphology, particle size and agglomeration stages were analyzed using scanning and transmission electron microscopy. Results show particles in the range of 14 to 40 nanometers, large agglomerates and crystalline phases formation.

Characterization of Strontium Ferrites Powders Obtained by High Energy Milling

2005 ◽  
Vol 498-499 ◽  
pp. 311-315
Author(s):  
P.I. Paulin Filho ◽  
R.R. Corrêa
Keyword(s):  
Electron Microscopy ◽  
Barium Carbonate ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Transmission Electron ◽  
Strontium Ferrites

Strontium ferrites powders were obtained by high energy milling process after calcinations of iron oxide and barium carbonate. Phase formations and crystallite size was determined using X-ray diffraction. Morphology, particle size and agglomeration stages were analyzed using scanning and transmission electron microscopy. Results show particles in the range of 14 to 40 nanometers, large agglomerates and crystalline phases formation.

Photocatalytic Degradation of Rhodamine B Dye through Zinc Oxide Obtained by High Energy Milling

2016 ◽  
Vol 881 ◽  
pp. 398-403
Author(s):  
Jeferson Almeida Dias ◽  
Vera Lúcia Arantes ◽  
Alfeu Saraiva Ramos ◽  
Tania Regina Giraldi ◽  
Marília Zani Minucci ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Life Time ◽  
High Energy ◽  
Heterogeneous Photocatalysis ◽  
Semiconductor Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Rhodamine B Dye

The heterogeneous photocatalysis has been developed to treatment of recalcitrant organic effluents such as the dyes. The chemical reactions occur on a semiconductor surface exposed to electromagnetic radiation. The objective of this study was evaluate the high energy milling as a mechanism to obtain fine powders of ZnO to utilization in photocatalysis. Raw ZnO was characterized by X-Ray diffraction, BET, sedigraph and Helium pycnometry and it was milled during four and ten hours in dry and wet media. The milled powders were characterized by X-Ray diffraction and they were evaluated in photocatalytic degradation of Rhodamine B dye. The results showed high purity of the powders before and after milling and the photocatalytic efficiency was function of processing conditions. The average half-life time for the dye varied between of 990.2 and 7.6 min wherein the powder obtained by four hours in dry media milling showed the best results of photodegradation.

Preparation of Nb-40Ti Powders by High-Energy Milling

2005 ◽  
Vol 498-499 ◽  
pp. 146-151
Author(s):  
Y.A. Giffoni ◽  
Erika Coaglia Trindade Ramos ◽  
Ana Sofia Ramos ◽  
Hugo Ricardo Zschommler Sandim ◽  
M.T.T. Pacheco
Keyword(s):  
Solid Solution ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
High Energy Milling ◽  
Porous Ti ◽  
Titanium Hydride Powder ◽  
Tih2 Powder ◽  
Ti Powder

Porous Ti-Nb alloys are promising candidates for biomedical applications. In the present study, alloy powders containing 60 wt-% Nb were prepared by high-energy milling of Nb, Ti, and/or TiH2 powders. The high-energy milling process was carried out in a planetary ball mill. The starting and as-milled materials were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). Elemental (Nb, and Ti) and TiH2 powder mixtures with composition Nb-40wt%Ti were mechanically alloyed for 2 to 30 h. The formation of a BCC Nb(Ti) solid solution by high-energy milling using elemental Ti powder to produce Nb-40Ti was observed after milling for 30 h. A HCP-Ti solid solution was formed after milling for 30 h due to the partial decomposition of titanium hydride powder mixture during high-energy milling.

DSC-TGA Hydrogen Evaluation during Mechanical Milling of AlFe Intermetallic

2013 ◽  
Vol 755 ◽  
pp. 105-110 ◽  
Author(s):  
E. García de León M. ◽  
O. Téllez-Vázquez ◽  
C. Patiño-Carachure ◽  
G. Rosas
Keyword(s):  
Mechanical Milling ◽  
Milling Time ◽  
Hydrogen Generation ◽  
Pure Aluminum ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

Fe40Al60 (at%) intermetallic alloy composition was obtained by conventional casting methods and subsequently subjected to high-energy mechanical milling under different conditions of humidity. All samples were characterized by X-ray diffraction patterns (XRD), transmission electron microcopy (TEM) and DSC-TGA thermogravimetric experiments. After the milling process, the amount of hydrogen generated was determined using thermogravimetric analysis and chemical reactions (stoichiometry). All techniques confirm the formation of bayerite phase which is attributed to the hydrogen embrittlement reaction between the intermetallic material and water to release hydrogen. It was observed that the hydrogen generation is increased as the ball milling time is increased. The quantity of hydrogen evaluated is similar to that obtained in previous reported experiments with pure aluminum and some of its alloys.

Synthesis of the Nanocrystalline/Nanosized NiFe2O4 Powder by Ceramic Method and Mechanical Milling

2012 ◽  
Vol 188 ◽  
pp. 27-30 ◽  
Author(s):  
Vasile Florin Tarța ◽  
Ionel Chicinaş ◽  
Traian Florin Marinca ◽  
Bogdan Viorel Neamţu ◽  
Florin Popa ◽  
...  
Keyword(s):  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Polycrystalline Nickel ◽  
Powder Morphology ◽  
Chemical Homogeneity ◽  
Ceramic Method ◽  
X Ray ◽  
Nanometric Range

The polycrystalline nickel ferrite - NiFe2O4has been obtained by ceramic route starting from a stoichiometric mixture of oxides (NiO and α-Fe2O3powders). The obtained NiFe2O4was subjected to high energy ball milling. The formation of NiFe2O4by ceramic method and also the evolution of the powder during milling were studied by X-ray diffraction. The mean crystallite size of the NiFe2O4continuously decreases with the increasing of the milling time and for all the milling time it is in nanometric range. The particles sizes are drastically reduced by milling process. For the milled samples, the particles size is ranging from tens of microns to few nanometers. The powder morphology and local chemical homogeneity were investigated by scanning electron microscopy (SEM) and respectively by energy dispersive x-ray spectrometry (EDX).

Modification of the Structural Characteristics of the Tungsten Powder through Short Mechanical Milling Processes

2011 ◽  
Vol 672 ◽  
pp. 255-258
Author(s):  
Dana Salomie ◽  
Nicolae Jumate
Keyword(s):  
Fine Structure ◽  
Mechanical Milling ◽  
Structural Characteristics ◽  
Tungsten Powder ◽  
High Energy ◽  
Milling Process ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Process Duration ◽  
X Ray

The objective of this study is to improve the sintering of W powder through increasing the density of the crystalline structure imperfections. The powder of W was processed by short processes of mechanical milling in a high energy planetary mill. The paper presents the influence of mechanical milling process duration upon the modifications of the structural characteristics of W powder. The fine structure has been studied by using X-ray diffraction.

scholarly journals Investigation of the Reaction between Fe2O3 and Si Activated by Ball Milling

1996 ◽  
Vol 51 (8) ◽  
pp. 915-922 ◽  
Author(s):  
Giorgio Concas ◽  
Francesco Congiu ◽  
Anna Corrias ◽  
Carlo Muntoni ◽  
Giorgio Paschina ◽  
...  
Keyword(s):  
Ball Milling ◽  
Oxygen Transfer ◽  
Amorphous Matrix ◽  
High Energy ◽  
Milling Process ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermediate Phases ◽  
Energy Ball

Abstract The path of the reaction between Fe2O3 and Si, activated by high energy ball milling, has been investigated by X-ray diffraction and Mössbauer spectroscopy. Hematite reduction involves oxygen transfer from Fe to Si with the formation of intermediate phases containing Fe(II), which are then reduced to Fe(0). A steady state is reached in the milling process where the reduction of stoichiometric amounts of Fe2O3 and Si is not complete and an amount of Fe(II) in an amorphous matrix still remains. The same intermediate compounds are also observed in the milling process of mixtures with higher Fe2O3 /Si molar ratio.

Study of the Sintering of Mixtures Al2O3-Nb2O5 and Y2O3-Nb2O5

2012 ◽  
Vol 727-728 ◽  
pp. 799-803 ◽  
Author(s):  
Ricardo F. Cabral ◽  
Marcelo Henrique Prado da Silva ◽  
Jose B. de Campos ◽  
Eduardo Sousa Lima
Keyword(s):  
Weight Loss ◽  
Mass Loss ◽  
Mole Fraction ◽  
Ball Mill ◽  
Rietveld Method ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling

Al2O3-Nb2O5 has been widely explored as one of the most used material for sintering mixing in the literature, due to its excellent hardness properties, used in armor. In this study, Al2O3-Nb2O5 and Y2O3-Nb2O5 powders were prepared, with 50% in mole fraction of each oxide. The mixtures were subjected to high energy milling in an eccentric ball mill for 3 h, dried and sieved in a sieve vibrator. The green bodies were compacted at 70 MPa and sintered from 1250 to 1650 °C for 3 h, at 100 °C steps. The materials were characterized by quantitative X-Ray diffraction (XRD) using Rietveld method and by mass loss. The Al2O3-Nb2O5 mixtures experienced a weight loss of 84% at sintering temperatures of 1550 and 1650 °C.

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