MODIFICATION OF BaCeO3 PROTONIC CONDUCTORS BY Ag AND Y DOPING

2011 ◽  
Vol 04 (02) ◽  
pp. 175-178
Author(s):  
MAGDALENA OSIADŁY ◽  
PAWEŁ PASIERB ◽  
STANISŁAW KOMORNICKI ◽  
MIECZYSŁAW RȨKAS
Keyword(s):  
Synthesis Method ◽  
Chemical Properties ◽  
Ionic Conductivities ◽  
Cell Voltage ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Total Electrical Conductivity ◽  
Acceptor Dopant ◽  
Physico Chemical ◽  
Synthesized Materials

Silver and yttrium dopants influence some physico-chemical properties of BaCeO 3 protonic conduction. Ag -acceptor dopant substituting Ba atom in BaCeO 3 compounds was studied for the first time. Ba 1-x Ag x Ce 1-y Y y O 3-δ (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.1) materials were synthesized by solid state reaction and by modified Pechini citric acid method. X-ray diffraction (XRD) and electrical properties measurements including open cell voltage (OCV) of electrochemical cells were used as experimental techniques. Basing on XRD results it was found that all synthesized materials crystallized in orthorhombic Pnma phase with some admixtures of other phases. Metallic Ag , CeO 2 or Y 2 O 3 with different concentrations were detected, depending on the composition, synthesis method and preparation details. DC electrical measurements showed that doping by Ag and Y decreased the total and ionic conductivities of the materials. The modification of charge transport properties was also observed, namely introduction of Ag led to the increase of electronic component of total electrical conductivity, especially at higher temperatures.

scholarly journals Experimental and Physico-Chemical Comparison of ZnO Nanoparticles’ Activity for Photocatalytic Applications in Wastewater Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 678
Author(s):  
Stefano Alberti ◽  
Irene Basciu ◽  
Marco Vocciante ◽  
Maurizio Ferretti
Keyword(s):  
Wastewater Treatment ◽  
Zno Nanoparticles ◽  
Energy Dispersive Spectrometer ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Commercial Sample ◽  
Synthetic Process ◽  
Physico Chemical ◽  
Photocatalytic Applications ◽  
Reflectance Measurements

In this contribution, the photoactivity upon activation by simulated sunlight of zinc oxide (ZnO) obtained from two different synthetic pathways (Acetate and Nitrate) is investigated for water purification. Different reagents and processes were exploited to obtain ZnO nanoparticles. Products have been characterized by means of X-Ray Diffraction, Scanning Electron Microscopy along with Energy Dispersive Spectrometer, Dynamic Light Scattering, and Diffuse Reflectance Measurements, to highlight the different outcomes ascribable to each synthesis. A comparison of characteristics and performances was also carried out with respect to commercial ZnO. Nanoparticles of this semiconductor can be obtained as aggregates with different degrees of purity, porosity, and shape, and their physical-chemical properties have been addressed to the specific use in wastewater treatment, testing their effectiveness on the photocatalytic degradation of methylene blue (MB) as a model pollutant. Excluding the commercial sample, experimental results evidenced a better photocatalytic behavior for the ZnO Nitrate sample annealed at 500 °C, which was found to be pure and stable in water, suggesting that ZnO could be effectively exploited as a heterogeneous photocatalyst for the degradation of emerging pollutants in water, provided that thermal treatment is included in the synthetic process.

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

2021 ◽  
Vol 14 (5) ◽  
pp. 445-449
Keyword(s):  
Zinc Ferrite ◽  
Single Phase ◽  
Chemical Properties ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Physico Chemical ◽  
Znfe2o4 Nanoparticles ◽  
Photoluminescence Studies ◽  
Combustion Technique

Abstract: Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

scholarly journals Controllable synthesis of pomelo peel-based aerogel and its application in adsorption of oil/organic pollutants

2019 ◽  
Vol 6 (2) ◽  
pp. 181823 ◽  
Author(s):  
Guangyu Shi ◽  
Yizhu Qian ◽  
Fengzhi Tan ◽  
Weijie Cai ◽  
Yuan Li ◽  
...  
Keyword(s):  
High Speed ◽  
Chemical Properties ◽  
Absorption Capacity ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Water Separation ◽  
Physico Chemical ◽  
Wide Range ◽  
Oil Water Separation ◽  
Oil Water

Oil/water separation is a field of high significance as it might efficiently resolve the contamination of industrial oily wastewater and other oil/water pollution. In this paper, an environmentally-friendly hydrophobic aerogel with high porosity and low density was successfully synthesized with renewable pomelo peels (PPs) as precursors. Typically, a series of sponge aerogels (HPSA-0, HPSA-1 and HPSA-2) were facilely prepared via high-speed dispersion, freeze-drying and silanization with methyltrimethoxysilane. Indeed, the physical properties of aerogel such as density and pore diameter could be tailored by different additives (filter paper fibre and polyvinyl alcohol). Hence, their physico-chemical properties including internal morphology and chemical structure were characterized in detail by Fourier transform infrared, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscope, Thermal gravimetric analyzer (TG) etc. Moreover, the adsorption capacity was further determined and the results revealed that the PP-based aerogels presented excellent adsorption performance for a wide range of oil products and/or organic solvents (crude oil 49.8 g g −1 , soya bean oil 62.3 g g −1 , chloroform 71.3 g g −1 etc.). The corresponding cyclic tests showed the absorption capacity decreased slightly from 94.66% to 93.82% after 10 consecutive cycles, indicating a high recyclability.

scholarly journals Effect of TiO2 Addition on Mortars: Characterization and Photoactivity

2019 ◽  
Vol 9 (13) ◽  
pp. 2598 ◽  
Author(s):  
M. J. Hernández-Rodríguez ◽  
R. Santana Rodríguez ◽  
R. Darias ◽  
O. González Díaz ◽  
J. M. Pérez Luzardo ◽  
...  
Keyword(s):  
Mercury Porosimetry ◽  
Setting Time ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physico Chemical ◽  
Setting Process ◽  
Flow Table ◽  
Negative Effect ◽  
Important Activity

In this study, mortar specimens were prepared with a cement:sand:water ratio of 1:3:0.5, in accordance with standard EN196-1. Portland CEM I 52.5 R grey (G) and white (W) cements were used, together with normalised sand and distilled water. Different amounts of TiO2 photocatalyst were incorporated in the preparation of the mortar samples. The effect of the addition of TiO2 was studied on mechanical properties of the mortar and cement including compressive and flexural strength, consistency (the flow table test), setting time and carbonation. Characterization techniques, including thermogravimetry, mercury porosimetry and X-ray diffraction spectroscopy (XRD), were applied to study the physico-chemical properties of the mortars. It was shown that adding the photocatalyst to the mortar had no negative effect on its properties and could be used to accelerate the setting process. Specimen photoactivity with the incorporated photocatalyst was tested for NOx oxidation in different conditions of humidity (0% RH and 65% RH) and illumination (Vis or Vis/UV), with the results showing an important activity even under Vis radiation.

scholarly journals Influence of Intercalation-Exfoliation-Reduction Technique towards the Physico-Chemical of VPO Catalysts

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Y. C. Wong ◽  
Y. H. Taufiq-Yap
Keyword(s):  
Electron Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vpo Catalysts ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Vpo Catalyst ◽  
Temperature Programmed ◽  
Lower Temperature ◽  
Synthesized Materials

Four VPO catalysts were synthesized through intercalation and exfoliation in various alcohols and subsequent reduction of the exfoliated VOPO4sheets with various alcohols to produce VOHPO4⋅0.5H2O. The resulting VOHPO4⋅0.5H2O that undergoes the intercalation-exfoliation-reduction (IER) process will be further activated into VPO catalysts, and addition of 1 mole % Bi(NO3)3⋅5H2O in the first stage of this experiment has also being investigated. The synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and temperature-programmed reduction (TPR) in H2. Catalytic evaluation of the IER-treated and Bi-doped VPO catalysts was also studied on microreactor. The VPO catalyst produced through IER using 2-butanol and ethanol with addition of Bi, IERC(2Bu-Et)RBi1, gave the highest MA selectivity due to reactive O2−species released from the additional crystalline V5+phase formed by doping 1% bismuth as promoter (O2−-V5+pair) at relative lower temperature. Nevertheless, the VPO catalyst produced through IER using isobutanol, IERC(isoBu), gave the highest activity due to high amount of reactive O−species released from V4+phase (O−-V4+pair) whereby the IERC(isoBu) catalyst synthesized consists of high percentage of V4+(93 %).

Characterization of Spent Catalysts during Hydrodemetallization of Atmosphere Residue

2011 ◽  
Vol 236-238 ◽  
pp. 538-542
Author(s):  
Yong Jun Liu
Keyword(s):  
Chemical Properties ◽  
Analytical Techniques ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Spent Catalysts ◽  
C Nmr

The deactivation behavior of industrial hydrodemetallization catalysts was investigated in the presented work. The main objective of the study is to contribute to a better understanding of the nature of the coke and metal deposition on the used catalysts by applying chemical analysis and various advanced analytical techniques, such as X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and solid-state carbon-13 nuclear magnetic resonance spectroscopy (13C NMR). The results are discussed scientifically based on the physico–chemical properties of origin and used catalysts.

scholarly journals Effect of Precursors on the Growth and Physiochemical Properties of Bio-mimetic ZnFe2O4 Nanocomposites for Photoelectrochemical Application

2020 ◽  
Vol 49 (12) ◽  
pp. 3219-3228
Author(s):  
Mohd Faizal Md Nasir ◽  
Wan Ramli Wan Daud ◽  
Mohamad Azuwa Mohamed ◽  
Mohamad Hafiz Mamat ◽  
Saifollah Abdullah ◽  
...  
Keyword(s):  
Zinc Ferrite ◽  
Synthesis Method ◽  
Photocurrent Density ◽  
Superior Performance ◽  
X Ray Diffraction ◽  
Physiochemical Properties ◽  
Fibril Structure ◽  
Vis Spectroscopy ◽  
Synthesized Materials ◽  
Transfer Properties

Zinc ferrite (ZnFe2O4) photocatalysts have been prepared with different types of zinc precursors using the bio-mimetic synthesis method. The kapok fibre (Ceiba pentandra (L.) Gaertn) used as a sacrificial template. The physiochemical of prepared bio-mimetic materials were carried out thoroughly in this work. The FESEM analysis in mimetic zinc ferrite catalysts shows a distinctly different structural transition under different precursors conditions. The acetate precursor formed a hollow tubular structure while other precursors formed a hierarchal fibril structure. X-ray diffraction analysis showed a distinctly different phase transition while UV-Vis spectroscopy recorded variable optical properties beneath different precursor conditions. The EDX and ATR-FTIR spectroscopy confirmed the formation of the pure composite after the annealing process. Different type of precursors that used have leads to tuneable of the magnetic properties of the prepared materials. Electrophoretic deposition (EPD) method has been used to fabricate the synthesized materials as photo-electrodes on the FTO substrate then evaluated for photoelectrochemical (PEC) application. Changing the precursors in the preparation method show a significant effect on physicochemical and PEC performance. The morphology and surface structure of the prepared catalysts are correlated with the alteration of the precursors, then attributed to the charge transfer properties of the photocurrent density in PEC system. The bio-templated zinc ferrite catalysts are promising photoanode in the photocatalytic activities. It is interesting to note that the various forms of multi-structure such as hollow fibril core-shell offers an enormous impact in designing active photocatalyst with superior performance.

scholarly journals Effect of Precursors on the Growth and Physiochemical Properties of Bio-mimetic ZnFe2O4 Nanocomposites for Photoelectrochemical Application

2020 ◽  
Vol 49 (12) ◽  
pp. 3165-3174
Author(s):  
Mohd Faizal Md Nasir ◽  
Wan Ramli Wan Daud ◽  
Mohamad Azuwa Mohamed ◽  
Mohamad Hafiz Mamat ◽  
Saifollah Abdullah ◽  
...  
Keyword(s):  
Zinc Ferrite ◽  
Synthesis Method ◽  
Photocurrent Density ◽  
Superior Performance ◽  
X Ray Diffraction ◽  
Physiochemical Properties ◽  
Fibril Structure ◽  
Vis Spectroscopy ◽  
Synthesized Materials ◽  
Transfer Properties

Zinc ferrite (ZnFe2O4) photocatalysts have been prepared with different types of zinc precursors using the bio-mimetic synthesis method. The kapok fibre (Ceiba pentandra (L.) Gaertn) used as a sacrificial template. The physiochemical of prepared bio-mimetic materials were carried out thoroughly in this work. The FESEM analysis in mimetic zinc ferrite catalysts shows a distinctly different structural transition under different precursors conditions. The acetate precursor formed a hollow tubular structure while other precursors formed a hierarchal fibril structure. X-ray diffraction analysis showed a distinctly different phase transition while UV-Vis spectroscopy recorded variable optical properties beneath different precursor conditions. The EDX and ATR-FTIR spectroscopy confirmed the formation of the pure composite after the annealing process. Different type of precursors that used have leads to tuneable of the magnetic properties of the prepared materials. Electrophoretic deposition (EPD) method has been used to fabricate the synthesized materials as photo-electrodes on the FTO substrate then evaluated for photoelectrochemical (PEC) application. Changing the precursors in the preparation method show a significant effect on physicochemical and PEC performance. The morphology and surface structure of the prepared catalysts are correlated with the alteration of the precursors, then attributed to the charge transfer properties of the photocurrent density in PEC system. The bio-templated zinc ferrite catalysts are promising photoanode in the photocatalytic activities. It is interesting to note that the various forms of multi-structure such as hollow fibril core-shell offers an enormous impact in designing active photocatalyst with superior performance.

scholarly journals Mg-Al-Cr2O7 Hydrotalcite-Like Catalysts Synthesized at Different pH Values for Styrene Oxidation

2020 ◽  
pp. 13-21
Author(s):  
Le Huy Tran ◽  
Thi Ngoc Mai Tran ◽  
Tuan Vu Anh ◽  
Pham Quoc Khanh ◽  
Thi Minh Thu Nguyen ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Styrene Oxidation ◽  
Preparation Conditions ◽  
Physico Chemical ◽  
Ph Conditions ◽  
Dichromate Anions ◽  
Co Precipitation ◽  
Styrene Conversion

Dichromate anions were intercalated between two consecutive hydroxide layers of [Mg0.6Al0.4(OH)2]0.40+ via co-precipitation at different pH conditions. The physico-chemical properties of the obtained solids were examined by physical methods such as X-ray diffraction (XRD), Infrared (IR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) and Energy-Dispersive Spectroscopy (EDS). The experimental results indicated that the amount of dichromate anions in the catalysts varies with the pH media. Also, the morphology, structure and chemical composition of the materials depends strongly on the preparation conditions. The Mg-Al-Cr2O7 hydrotalcite-like compounds are used as heterogeneous catalysts for the styrene oxidation with H2O2 at mild conditions. The styrene conversion is about 20-50% while styrene selectivity remains rather high.

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