Exploitation of Surface-Sensitive Electrons in Scanning Electron Microscopy Reveals the Formation Mechanism of New Cubic and Truncated Octahedral CeO2 Nanoparticles

ChemCatChem ◽  
2011 ◽  
Vol 3 (6) ◽  
pp. 1038-1044 ◽  
Author(s):  
Shunsuke Asahina ◽  
Seiichi Takami ◽  
Takeshi Otsuka ◽  
Tadafumi Adschiri ◽  
Osamu Terasaki
2012 ◽  
Vol 174-177 ◽  
pp. 592-595
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

The organization of nanostructures across extended length scales is a key challenge in the design of integrated materials with advanced functions. PbZr0.52Ti0.48O3multilayer disks which were constructed by oriented rectangle nanoparticles were easily prepared by a simple surfactant-free hydrothermal process. The as-prepared powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-prepared PZT disks were constructed by self-assembly of rectangle nanoparticles by a perfect manner. The formation mechanism of the products was discussed.


2012 ◽  
Vol 528 ◽  
pp. 176-179
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Xin Wang ◽  
Song Li ◽  
Yu Jiang Wang ◽  
...  

Using polymer as a surfactant, we successfully synthesized of PbTiO3 crystals with a self-assembly structure by a hydrothermal process. The as-obtained powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results show that the presence of PVP, PEG and PVA plays a key role on the formation of self-assembly structure and the corresponding formation mechanism was briefly discussed.


2021 ◽  
Vol 1 (3) ◽  
pp. 176-189
Author(s):  
Prathima Prabhu Tumkur ◽  
Nithin Krisshna Gunasekaran ◽  
Babu R. Lamani ◽  
Nicole Nazario Bayon ◽  
Krishnan Prabhakaran ◽  
...  

Due to its excellent physicochemical properties, cerium oxide (CeO2) has attracted much attention in recent years. CeO2 nanomaterials (nanoceria) are widely being used, which has resulted in them getting released to the environment, and exposure to humans (mostly via inhalation) is a major concern. In the present study, CeO2 nanoparticles were synthesized by hydroxide-mediated method and were further characterized by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction Spectroscopy (XRD). Human lung epithelial (Beas-2B) cells were used to assess the cytotoxicity and biocompatibility activity of CeO2 nanoparticles. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and Live/Dead assays were performed to determine the cytotoxicity and biocompatibility of CeO2 nanoparticles. Generation of reactive oxygen species (ROS) by cerium oxide nanoparticles was assessed by ROS assay. MTT assay and Live/Dead assays showed no significant induction of cell death even at higher concentrations (100 μg per 100 μL) upon exposure to Beas-2B cells. ROS assay revealed that CeO2 nanoparticles did not induce ROS that contribute to the oxidative stress and inflammation leading to various disease conditions. Thus, CeO2 nanoparticles could be used in various applications including biosensors, cancer therapy, catalytic converters, sunscreen, and drug delivery.


2012 ◽  
Vol 184-185 ◽  
pp. 830-833
Author(s):  
Guo Hui Xu ◽  
Lin Lin Yang ◽  
Yang Hui Zu ◽  
Wei Guo Li ◽  
Yu Jiang Wang ◽  
...  

K0.5Bi0.5TiO3 nanoparticles and quadrate nanoflakes were successfully prepared by a hydrothermal process. The as-synthesized powders were examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results suggest that the precursor plays an important role on the formation of K0.5Bi0.5TiO3 crystals and the formation mechanism was also discussed.


2012 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Ida Sriyanti ◽  
Mikrajuddin Abdullah

Nd-CeO2 nanoparticles have been synthesized with a simple heating method. The microstructure and morphologyof material were characterized by a Scanning Electron Microscopy (SEM), and the conductivity of the material wasmeasured by an AC Impedance Spectroscopy. At room temperature we obtain a sample prepared at 9% at/at. Ndhave the highest conductivity of 1.47 x 10-4. Scm-1. This conductivity surpass the value reported by Anefleous for Nd-CeO2 (NDC) material prepared by different method. Sample has been 49 nm crystals size obtained from FWHM .Thisresult proves that a simple heating method is the promising for synthesizing electrolyte materials for SOFCapplication.


2011 ◽  
Vol 287-290 ◽  
pp. 394-400
Author(s):  
Zhen Li ◽  
Chang Hui Yang ◽  
Kui Yang ◽  
Chong Wang

The morphology of PVA/Na-MMT composite under different freezing technology conditions was studied. Inlfuence of PVA content and frozen conditions on microstructure and formation mechanism of PVA/Na-MMT composite materials were analyzed using scanning electron microscopy(SEM). The experiment results show that the structure of freeze-dried PVA/Na-MMT composite is influenced by both frozen technology and PVA dosage. PVA/Na-MMT composite frozen in Low-temperature refrigerator presented honeycomb-like structure when PVA dosage was 1%, and when the dosage of PVA was 2%, 3%, 4% respectively, the composite exposed wrinkle superposition structure. In liquid nitrogen frozen, Fiber-like structure of PVA/Na-MMT composite was obtained when the PVA content more than 3%.


2013 ◽  
Vol 740-742 ◽  
pp. 43-47 ◽  
Author(s):  
Gennadi A. Emelchenko ◽  
Andrey A. Zhokhov ◽  
Ilya I. Tartakovskii ◽  
Andrey A. Maksimov ◽  
Edward A. Steinman

The structural defects in the single 6H-SiC crystals grown by the PVT method have been studied by the scanning electron microscopy, Raman scattering and photoluminescence techniques. The formation mechanism of the defects, micropipes and parasitic polytypes 4H and 15R, observed in the single 6H-SiC crystal has been proposed.


2011 ◽  
Vol 64 (11) ◽  
pp. 1494 ◽  
Author(s):  
Hao Li ◽  
Jinyun Liao ◽  
Zhen Jin ◽  
Xibin Zhang ◽  
Xiuxian Lu ◽  
...  

Flowerlike Ni microcrystals composed of star-shaped Ni nanorods with a diameter of ~200 nm were fabricated by a facile chemical reduction process, in which ethylenediamine tetraacetic acid sodium (EDTA) was used as complexant to assist in the formation of the flowery shape of the sample. The products were characterized by X-ray diffractometer, scanning electron microscopy, energy-dispersive X-ray spectroscopy and superconducting quantum interference device magnetometer. Scanning electron microscopy images indicated the typical size of the flowery Ni microcrystals was 2–3 μm and the length of the star-shaped Ni nanorods was in the hundreds of nanometers up to micron scale. The X-ray diffraction pattern showed the Ni microcrystals were present in the face-centred cubic phase and magnetic measurement results demonstrated the greatly enhanced coercivity of the sample (168.5 Oe) at room temperature. Based on the evolution of the structure and the morphology of products with increasing reaction time, a possible formation mechanism was proposed to illustrate the growth of the flower-like Ni architecture.


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