Preparation and Photocatalysis of Nano-Zn/Ce Composite Oxides

2014 ◽  
Vol 67 (4) ◽  
pp. 657 ◽  
Author(s):  
Xiuping Li ◽  
Yuchun Zhai ◽  
Peihua Ma ◽  
Rongxiang Zhao

Metal oxide photocatalysts often lead to partial or complete mineralization of organic pollutants. On irradiation with UV-visible light, metal oxides catalyze redox reactions in the presence of air and O2 and water. Using ascorbic acid as a new combustion agent, ZnO was rapidly synthesized. Nano-Zn/CeO2 composites were prepared by a heterogeneous-precipitation method using (NH4)2CO3 as precipitation agent. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectrometry, ultraviolet spectrophotometry, and differential thermal analysis were used to analyse the microstructures of the synthesized materials. Differential thermal analysis, transmission electron microscopy, and X-ray diffraction analyses indicated that ZnO was coated by CeO2. Herein, a nano-Zn/Ce composite was explored as a catalyst for Rhodamine B photodegradation with a 125-W lamp as the UV radiation source in a batch reactor. The results show the photocatalytic properties of the nano-Zn/Ce composite were superior to ZnO, CeO2, and nano-Ce/Zn composites.

Clay Minerals ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 351-359 ◽  
Author(s):  
A. Violante ◽  
P. M. Huang

AbstractThe influence of kaolinite and montmorillonite on the identification of pseudoboehmite was studied by X-ray diffraction (XRD), differential thermal analysis (DTA), infrared absorption (IR), and transmission electron microscopy (TEM). In the randomly oriented samples containing different proportions of the clay minerals and pseudoboehmite, pseudoboehmite was not easily detectable by XRD even in a sample containing 40% of pseudoboehmite. Preheating of the samples at 110-300°C improved the detection limit to 30%. In samples obtained by mixing suitable amounts of the suspensions of the clay minerals (<2μm)and pseudoboehmite, the identification of pseudoboehmite was even more difficult. In oriented samples, pseudoboehmite was detectable only when present in amounts >30%, at low full-scale counts per second (1000-400 cps), on preheated samples in the presence of kaolinite, or on the samples that were Mg-saturated and solvated with ethylene glycol in the presence of montmorillonite. Identification of pseudoboehmite in the presence of kaolinite or montmorillonite by DTA, IR or TEM failed, even in samples containing 50% pseudoboehmite. In the presence of both kaolinite and montmorillonite (1:1 w/w), the identification of pseudoboehmite became much more difficult than in the presence of either mineral alone. The presence of pseudoboehmite in soils may, thus, be undetectable by standard clay mineralogical analyses.


Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 391-404 ◽  
Author(s):  
J. E. F. C. Gardolinski ◽  
G. Lagaly ◽  
M. Czank

AbstractKaolinite and synthetic γ-Al(OH)3 (gibbsite or hydrargillite) were reacted with phenylphosphonic, phenylphosphinic and 2-nitrophenol-4-arsonic acids. The products were studied by powder X-ray diffraction, transmission electron microscopy/selected area electron diffraction/ energy dispersive X-ray/Fourier transform infrared and simultaneous thermogravimetric/differential thermal analysis. The acids were not intercalated but, instead, easily destroyed the structure of the minerals. Lamellar Al phenylphosphonate and aluminium phenylphosphinate and phenylarsonate with polymeric linear-chain structures were formed from kaolinite. The reaction between gibbsite and the same acids yielded almost identical products. No evidence of formation of grafted kaolinite derivatives after the reaction with phenylphosphonic acid was found.


2006 ◽  
Vol 6 (1) ◽  
pp. 254-257 ◽  
Author(s):  
Emanuela Callone ◽  
Giovanni Carturan ◽  
Adriana Sicurelli

Sn, Sn–Sb, Ti, Zr, Fe, Ce and In oxides are prepared as nanometric powders by the hydrolytic route, starting from their ordinary salts or alkoxides, in the presence of 5% w/v starch as a non-ionic stabilizer of crystallization nuclei versus coalescence and flocculation. The starch can be degraded by α-amylase to soluble glucosidic oligomers, which may further be degraded by yeast to CO2 and ethanol. The nanoparticle features of prepared oxides result from experimental evidence based on X-ray diffractometry, transmission electron microscopy, differential thermal analysis/thermogravimetry coupled to mass spectrometry, specific surface area and porosity of samples obtained by curing in the 80–600 °C interval.


2019 ◽  
Vol 70 (11) ◽  
pp. 3931-3934
Author(s):  
Irina Fierascu ◽  
Raluca Somoghi ◽  
Cristian Andi Nicolae ◽  
Nicolae Stanica ◽  
Radu Claudiu Fierascu

An inorganic/organic magnetic nanocomposite was synthesized and analytically characterized using X-ray fluorescence, X-ray diffraction, transmission electron microscopy and thermal analysis. The evaluation of the magnetic properties revealed that both the magnetite and the magnetite/chitosan nanocomposite are superparamagnetic with a paramagnetic component, having the saturation magnetization values of 48.04 emu/g, and 41.3 emu/g, respectively. The synthesized material is indented for the adsorption of two known commercial-available pesticides (active ingredients deltamethrin and thiamethoxam, respectively) from aqueous solutions.


2013 ◽  
Vol 592-593 ◽  
pp. 517-520
Author(s):  
Ivona Černičková ◽  
Peter Švec ◽  
Emília Illeková ◽  
Dusan Janickovic ◽  
Pavol Priputen ◽  
...  

The U-phase in the Al72Pd12.8Co15.2alloy was studied under non-equilibrium (casting, differential thermal analysis) and near-equilibrium (long-term annealing) conditions to consider its compositional homogeneity. In the investigation, scanning electron microscopy including energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, and differential thermal analysis were used. Contrary to the finding reported for the Al69.8Pd13.8Co16.4alloy, the results obtained for the investigated Al72Pd12.8Co15.2alloy did not confirm the compositional heterogeneity of the near-equilibrium U-phase after annealing at 700°C for 2000 h and at 850°C for 500 h.


2015 ◽  
Vol 778 ◽  
pp. 183-186
Author(s):  
Yan Xia Han ◽  
Qian Nan Li ◽  
Hai Yun Shen ◽  
Qiu Hua Yang

Ce3+doped cubic KLaF4system was synthesized by co-precipitation method. The sample was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis spectrophotometer and fluorescence spectrophotometer. The result indicated the nanoparticle diameter of KLaF4:Ce3+was 12.5 nm. The KLaF4:Ce3+had a stronger absorption at 250 nm, which could be explained by d elecronic transition of Ce3+. The maximum emission peak of KLaF4:Ce3+was 355 nm in its luminescent spectrum, and emission band of Ce3+also belonged to 5d→4f transition.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 368
Author(s):  
Franc Zupanič ◽  
Matej Steinacher ◽  
Sandi Žist ◽  
Tonica Bončina

In this work, we investigated a novel Al-Mg-Si alloy, which was developed from an AA 6082, in order to considerably improve the yield and tensile strengths whilst retain excellent ductility. The new alloy possesses a higher content of Si than specified by AA 6082, and, in addition, it contains copper and zirconium. The alloy was characterized in the as-cast condition, after homogenization, extrusion, and T6 heat treatment using light microscopy, scanning and transmission electron microscopy with energy dispersive spectrometry, X-ray diffraction, differential thermal analysis and tensile testing. After T6 temper, tensile strengths were around 490 MPa with more than 10% elongation at fracture. The microstructure consisted of small-grained Al-rich matrix with α-AlMnSi and Al3Zr dispersoids, and Q′-AlCuMgSi and β-Mg2Si-type precipitates.


2019 ◽  
Vol 70 (11) ◽  
pp. 3931-3934
Author(s):  
Irina Fierascu ◽  
Raluca Somoghi ◽  
Cristian Andi Nicolae ◽  
Nicolae Stanica ◽  
Radu Claudiu Fierascu

An inorganic/organic magnetic nanocomposite was synthesized and analytically characterized using X-ray fluorescence, X-ray diffraction, transmission electron microscopy and thermal analysis. The evaluation of the magnetic properties revealed that both the magnetite and the magnetite/chitosan nanocomposite are superparamagnetic with a paramagnetic component, having the saturation magnetization values of 48.04 emu/g, and 41.3 emu/g, respectively. The synthesized material is indented for the adsorption of two known commercial-available pesticides (active ingredients deltamethrin and thiamethoxam, respectively) from aqueous solutions.


2008 ◽  
Vol 368-372 ◽  
pp. 635-637
Author(s):  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu ◽  
Hai Yan He

Nanocrystalline Y2BaCuO5 was prepared by a co-precipitation method with aid of ultrasonic irradiation using Y2O3, CuCl2 and BaCl2 as source materials. The crystallization and morphology of the prepared nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. Results showed that Y2BaCuO5 monophase can be prepared at 900°C with NaOH + NaCO3 mixture as precipitator. Particle size of Y2BaCuO5 crystallites decreases with the increase of sonicating power. Around 30 nm Y2BaCuO5 crystallites could be achieved when sonicating power increased to 300 W.


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