Chemical synthesis and structural characterization of nanocrystalline powders of pure zirconia and yttria stabilized zirconia (YSZ)

Ray, Jagadish C.; Pati, Ranjan K.; Pramanik, Panchanan

doi:10.1016/s0955-2219(99)00293-9

Cited by 90 publications

(33 citation statements)

References 17 publications

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“…The strongest diffraction peak of monoclinic structure which appeared at 28.2° (2theta) was due to the (111) plane, and the major peak for the tetragonal structure seen at 30.5°( 2theta) was attributed to the (101) plane. The obtained structures are comparable to the JCPDS data (Card No.37-1484) (Jiao et al, 2003;Ray et al, 2000) for the monoclinic and standard JCPDS data (Card No.17-0923) for the tetragonal structure. Comparing the intensity of the monoclinic and tetragonal peaks shows that the monoclinic peaks are more intense than tetragonal peaks and it can be concluded that the samples contain more monoclinic structure than tetragonal.…”

Section: Characterisationsupporting

confidence: 79%

“…This problem can be solved by modifying zirconium nanoparticles with acids such as sulphates (Shao et al, 2006;Xu et al, 2005;Adamski et al,2008;Mekhemer & Ismail, 2000;Jiao et al, 2003) and phosphates (Ray et al, 2000) to yield solid acids of a wide range of strengths. This acid-modified zirconia has been found to increase water retention, improve proton conductivity and reduce the methanol crossover in the membrane Bondars et al, 1995;Chuah et al, 2001) and be more stable than other solid super acids .…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of zirconia-based solid acid nanoparticles for fuel cell application

Sigwadi

Mavundla

Moloto

et al. 2016

J. energy South. Afr.

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Zirconia nanoparticles were prepared by the precipitation and ageing methods. The precipitation method was performed by adding ammonium solution to the aqueous solution of zirconium chloride at room temperature. The ageing method was performed by leaving the precipitate formed in the mother liquor in the glass beaker for 48 hours at ambient temperatures. The nanoparticles from both methods were further sulphated and phosphated to increase their acid sites. The materials prepared were characterised by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Brunauer-EmmettTeller (BET), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) methods. The XRD results showed that the nanoparticles prepared by the precipitation method contained mixed phases of tetragonal and monoclinic phases, whereas the nanoparticles prepared by ageing method had only tetragonal phase. The TEM results showed that phosphated and sulphated zirconia nanoparticles obtained from the ageing method had a smaller particle size (10-12 nm) than the nanoparticles of approximately 25-30 nm prepared by precipitation only. The BET results showed that the ZrO 2 nanoparticles surface area increased from 32 to 72 m 2 /g when aged.

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Section: Characterisationsupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Synthesis of zirconia-based solid acid nanoparticles for fuel cell application

Sigwadi

Mavundla

Moloto

et al. 2016

J. energy South. Afr.

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“…The diagram shows that milling time and sintering temperature exert an effect on crystallite size distribution. The increase in the crystallite size testifies that monoclinic ZrO2 transforms into the tetragonal form at ≈ 1000 °C [10]. In multicomponent systems, basically the addition of one component to the others increases the crystallization temperatures compared to pure oxides.…”

Section: Resultsmentioning

confidence: 99%

“…In the solid-state process, the mixture of ZrO2 and TiO2 powders was usually sintered at temperature as high as 1100 °C to ensure the phase formation. Sintering of such high temperature-derived powders would be at very high temperatures ranging from 1400 °C to 1600 °C [10]. Tables 1 and 2 show the results of X-ray diffraction (XRD) patterns for both series of powder samples (S25/T25/Z50 and S15/T35/Z50) of the ternary SiO2-TiO2-ZrO2 system heattreated for 1 hour at 1000 °C.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Nanoporous SiO2-TiO2-ZrO2 Ceramics Using Sol-gel Technology

Karpe

Mežinskis

Timma

2014

Material Science and Applied Chemistry

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-The aim of research is to develop an area of nanoporous ceramics of ternary systems. Nanoporous ceramic system SiO2-TiO2-ZrO2 has been synthesized via sol-gel technology by hydrolysis of tetraethylorthosilicate (TEOS), zirconia and titanium alcoxides solutions. The sols have been polymerized at room temperature to obtain gels and dried at 100 o C, then milled for 1 or 6 hours for particle homogenization, pressed into samples, and then sintered at 800 o C or 1000 o C in air. The samples have been characterized by XRD, particle size distribution, crystallite size distribution, compressive strength. Porosity of ceramic samples has been determined by nitrogen adsorption-desorption isotherms.

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“…ZrO 2 exists in three main polymorphic phases [5], namely, tetragonal, monoclinic, and cubic. At temperatures \1170°C, the monoclinic phase (m) of an unalloyed ZrO 2 is thermodynamically stable.…”

Section: Introductionmentioning

confidence: 99%

pH-responsive lyotropic liquid crystals for the preparation of pure cubic zirconia nanoparticles

Liu

Zhang

et al. 2016

Appl. Phys. A

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We present a lyotropic liquid crystal system consisting of SDS/Triton X-100/water at 25°C. This system is respond to pH variations with a phase switch. When pH is altered from alkaline (pH 13) to acidic (pH 2) conditions, phase change occurs from a bicontinuous hexagonal phase to a partially hexagonal phase until it disappears. The hexagonal phase under alkaline conditions is stable. Thus, this system is an ideal candidate for the preparation of pure cubic ZrO 2 nanoparticles. XRD results confirm that the as-synthesized powder is composed of pure cubic ZrO 2 . These nanoparticles also exhibit a thermal stability of up to 800°C. The size and morphological characteristics of the nanoparticles are greatly affected by ZrOCl 2 concentration. The mechanism of zirconia nanoparticle synthesis in a lyotropic hexagonal phase was proposed.

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Chemical synthesis and structural characterization of nanocrystalline powders of pure zirconia and yttria stabilized zirconia (YSZ)

Cited by 90 publications

References 17 publications

Synthesis of zirconia-based solid acid nanoparticles for fuel cell application

Synthesis of zirconia-based solid acid nanoparticles for fuel cell application

Synthesis of Nanoporous SiO2-TiO2-ZrO2 Ceramics Using Sol-gel Technology

pH-responsive lyotropic liquid crystals for the preparation of pure cubic zirconia nanoparticles

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