Influence of Nb2O5 on the varistor behavior of TiO2 …

Based on the single sinter process, five disk samples of (Sr, Bi, Si, Ta)-doped TiO2-based varistor ceramics, which were sintered separately at the temperature of 1200–1400°C for 2.5h, were ...

Roles of Ball Milling Pretreatment and Titanyl Sulfate in ...

Production of 5-hydroxymethylfurfural (HMF) from cellulose has been expected for a long time, but most catalytic systems generally give low yield and selectivity due to the difficulty of balancing cellulose deconstruction with the uncontrollable degradation of the target product under harsh conditions. Here we show that the ball milling pretreatment could markedly facilitate the …

Affect of binder on mechanical and physical ... - …

High-energy ball milling initiates a solid-state reaction in an equimolar mixture of TiO2 and ZrO2. The first stage of ball milling induced the transformation of anatase TiO2 to high-pressure ...

(PDF) Effect of Cr 2 O 3 in the varistor behaviour of TiO ...

The powder was obtained by mixing the formation of several phases on the grain in a ball milling process with alcoholic media. Then boundary of ZnO [3, 4]. ... (Nb, Ba)-doped The best non-linear coefficient ( a = 12) was TiO2 ceramics have useful varistor properties, with obtained when molar concentrations of 0.05% Cr203 low non-linearity ...

Tailoring materials by high-energy ball milling: TiO2 ...

We carried out a rational design of catalyst supports by high-energy ball milling. Tailored mixtures of TiO 2 crystalline phases were obtained using rotational speed and milling time as variable parameters. Polymorphic transformation from anatase to rutile through high-pressure TiO 2 (II) as intermediate was confirmed by X-ray Diffraction (XRD), Raman …

STUDY OF THE EFFECT OF WO3 AND Bi2O3 ON THE …

on the microstructure and electrical properties of a TiO 2 based varistor 982 fields (Ali, Mustapa, Ghazali, Sujitno, & Ridha, 2013; Aznilinda, Herman, Ramly, ... The powders were mixed by ball milling where ethanol was used as a solvent. The process was then followed by drying the slurry at 600C for 24 hours and was then followed by sieving ...

Fe- and Eu-doped TiO2 Photocatalytical Materials …

X-ray Diffraction. The X-ray diffraction patterns of the systems consisting of titanium dioxide (anatase) undoped and doped with Fe and Eu in different proportions and with different bmt have been registered. Table 1 shows the phase composition of the undoped and iron and europium doped TiO 2 samples prepared in air or N 2 atmosphere at various milling times, as …

Nonlinear electrical properties of MnO2-doped TiO2 ...

Figure 2 shows the microstructure of TiO 2-based varistors with different amounts of MnO 2.It is found that the addition of MnO 2 has a remarkably effect on the microstructure of TiO 2 varistor ceramics. As the content of MnO 2 reaches up to 0.5 mol%, all the samples display dense microstructures and no pores appear at the grain boundary. The standard deviations of …

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1.0mol% MnO 2-0.5mol% SiO -0.5mol% TiO . Then, 0.15mol% In 2O 3, 0.15mol% La and 0.15mol% Ga was separately added into ZnO-based varistor ceramics. The as-prepared undoped specimens and specimens doped with In 2O 3,La,orGa were named as Z-0, Z-I, Z-L and Z-G, respectively. The raw materials were mixed with deionized water in a planetary ball ...

Effect of ball milling on reaction between TiO2 and Al ...

Titanium Aluminide based composites with Al2O3 reinforcement can be produced via reaction of Al with TiO2. These composites are considered as low price materials for high temperature applications. In this research, the effect of ball milling on 3TiO2/7Al system was investigated. On the basis of obtained results, ball milling for 0 to 60 h does not lead to …

egum et al, Material ci Enga, Journal of Material ...

of TiO 2 ceramic based varistor is performed with the addition of PVA binder as processing aid and Bi 2 O 3 and Ta O 5 as dopants. This research ... during the ball milling process. The prepared slurry was sieved and dried in an oven at 60°C for 24 hrs. The dried powder was grinded and sieved. Cylindrical discs of 20 mm diameter were prepared by

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performance of the varistor ceramics through the process of microstructure development [ ]. As a multivariate case, a pervious study has demonstrated that the phase equilib-rium formation and as a consequence the microstructure development are strongly in uenced by the TiO 2 /Bi 2 O 3 in low-voltage varistor ceramics and the Sb 2 O 3 /Bi 2 O 3 ...

Influence of Nb2O5 on the varistor behavior of …

This work investigated the influence of Nb2O5 dopant on the varistor behavior of the ternary system (99.95 − x)%TiO2, 0.05 %Cr2O3, x%Nb2O5, where x = 0.10; 0.15; 0.20; 0.25 % in mol. The processing was carried out using the conventional oxide mixture method. The initial oxides were homogenized in alcoholic media in a ball mill, for 3 h, dried in oven and …

Preparation and characterization of high nonlinear TiO2 ...

The present work successfully fabricated high nonlinear TiO2 varistor ceramics by co-doping with Ge and GeO2, HIP sintering and annealing in nitrogen. Further, its high nonlinear mechanism is investigated. XRD, XPS, SEM-EDAX and SEM analyses demonstrated that annealing can cause acceptor ions segregate to grain boundaries, which increases the …

High energy ball milling process for nanomaterial synthesis

In our research, we use the high-energy ball milling technique to synthesize various nanometer powders with an average particle size down to several nm, including nano-sized a-Fe 2 O 3 based solid solutions mixed with varied mole percentages of SnO 2, ZrO 2 and TiO 2 separately for ethanol gas sensing application, stabilized ZrO 2 based and TiO ...

Effects of high-energy ball milling oxide-doped and ...

XU Dong, et al/Trans. Nonferrous Met. Soc. China 22(2012) 1423−1431 1425 components of varistor ceramics, and they are ZnO phase, spinel phase …

Ball milling – A green and sustainable technique for the ...

Ilmenite is a naturally available mineral that is highly applicable in the synthesis of pure TiO 2.Titania mainly presents in four polymorphs as rutile, anatase, brookite and TiO 2 –B. Titania could be mined from minerals such as ilmenite, leucoxene and rutile among which ilmenite is the main source. Ball milling is a mechanical activation method used before subjecting ilmenite to …

The Effect of Sintering Conditions on the Microstructure ...

The microstructure and electrical properties of ZnO-Bi2O3-based varistor ceramics prepared by the high-energy ball milling were studied. The varistor ceramics samples were characterized by …

Effect of ball milling process on the photocatalytic ...

After the secondary ball milling process, parts of the samples were calcined at high temperatures. X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy (DRS) were used to observe the powder particle size, structural defect, bandgap, and absorption spectrum of …

Effects of Zn Doping and High Energy Ball Milling on the ...

ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Elias Stefanakos, for the opportunity to work with him and the members of the Clean Energy Research Center.

Preparation of Pd/SiO2 Catalysts by a Simple Dry Ball ...

Preparation of Pd/SiO2 Catalysts by a Simple Dry Ball-Milling Method for Lean Methane Oxidation and Probe of the State of Active Pd IF 3.52) Pub Date :, DOI: 10.3390/catal11060725 Li Yang, Chao Fan, Li Luo, Yanyan Chen, Zhiwei Wu, Zhangfeng Qin, Mei Dong, Weibin Fan, Jianguo Wang

Synthesis of TiO2-Carbon Nanotubes through ball-milling ...

Synthesis of TiO 2-Carbon Nanotubes through ball-milling method for mineralization of oxamic acid (OMA) ... In the case of SG based materials, the ball milling process decreased the BET surface area when compared with composite synthesized by the sol-gel method and this reduction was more pronounced for the composite prepared with original ...

Predicting thermal conductivity behaviour of ZnO, TiO2 …

While mixing the TiO 2 and ZnO Nps by the ball milling process, the nanoparticles are evenly blended with each other forming nano-composites. The XRD pattern of the TZO NC displays diffraction peaks corresponding to both TiO 2 and ZnO Nps substantiating the presence of both phases in the nanocomposites (figure 1 (c)).

Ge-added TiO2–Ta2O5–CaCO3 varistor ceramics - …

The influence of doping with Ge on the nonlinear coefficient α and the breakdown electric field E B of TiO 2 –Ta 2 O 5 –CaCO 3 varistor ceramics was investigated. In this study, TiO 2 –Ta 2 O 5 –CaCO 3 varistor ceramics added with Ge was successfully prepared using the traditional method of ball milling–molding–sintering. The electrical performance, including the …

Optimization of Bi2O3, TiO2, and Sb2O3 Doped ZnO …

In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this …

Photocatalytic improvement of Y3+ modified TiO2 …

Photocatalytic improvement of Y3+ modified TiO 2 prepared by a ball milling method and application in shrimp wastewater treatment Di Wu, †ab Chen Li,†ab Dashuai Zhang, ab Lili Wang,ab Xiaopeng Zhang, *abc Zaifeng Shi*ab and Qiang Lin ab Semiconductor photocatalysis is an advanced oxidation process driven by solar energy which has

The Microstructure and Electrical Behavior of TiO2 ...

A comparative study of the microstructures of two kinds of TiO2 based varistor materials processed from the slurry using magnetized water and regular deionized water is conducted. The additives in the form of oxides of Nb, Ce, Ca, and Si were used in the recipe. The electrical behavior reveals that the water magnetized at 0.2 T yielded lower varistor voltage …

A novel ball milling technique for room temperature ...

Herein, we report an inexpensive method for mass-scale production of TiO 2 ETMs at room temperature (RT ∼ 30 °C), involving the grinding of large clumps of an-TiO 2 to form a suspension of TiO 2 nanoparticles (NPs) in isopropyl alcohol for meso-superstructured PSCs. This process does not involve any chemical synthesis; it is a purely ...

Electrochemical properties of the TiO2(B) powders ball ...

Belt or wire shaped TiO2(B) particles were synthesized for lithium ion battery application by a hydrothermal and heat treatment process. In order to facilitate TiO2(B)/C composites fabrication, the synthesized TiO2(B) particles were crushed into smaller sizes by ball milling. Ball mill treated TiO2(B) particles of less than 1.0 μm with a fraction of anatase phase, …