scholarly journals Facile and Surfactant-Free Synthesis of Hierarchical ZnO Microstructures

Author(s):  
Kezhen Qi ◽  
Ruidan Wang ◽  
Jiaqi Fu ◽  
Ke Chen ◽  
Chunying Zuo

Hierarchical ZnO crystals with flower-like microstructures were successfully synthesized via a facile hydrothermal route without using any surfactants. The morphology of these microstructures can be easily controlled by adjusting the pH of the reaction solution. The products were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). Furthermore, a possible growth mechanism of ZnO hierarchical microstructures was proposed.  

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Wang ◽  
Yang Liu ◽  
Yang Jiao ◽  
Fengyu Qu ◽  
Qingzhi Pan ◽  
...  

The well-aligned Ag2O/ZnO microflowers heterostructure was synthesized by a straightforward two-step procedure. The diameters of the as-synthesized products were as much as 1.5 μm. The as-grown Ag2O/ZnO heterostructure was investigated by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and photoluminescence (PL) spectroscopy analysis. A possible growth mechanism for flowerlike Ag2O/ZnO heterostructure was proposed based on the experimental results. Compared with pure ZnO microflowers, PL spectrum of the composite with only one strong peak at 383 nm showed good intrinsic emission.


2018 ◽  
Vol 163 ◽  
pp. 05008
Author(s):  
Anna Skawińska

This paper presents the results of the studies carried out in the model systems and concerning the tobermorite synthesis with an addition of metahalloysite. Quartz sand and quicklime were the main raw material constituents. The mixtures in the form of slurries underwent hydrothermal treatment with an addition of metahalloysite (5%, 10%, 15%, 20% and 30%) for 4 hours and 12 hours. The resultant composites were analysed for their phase composition using X-ray powder diffraction. The microstructure was examined using the Scanning Electron Microscope. Tobermorite was the principle reaction product. When 30% metahalloysite was added to the mixture containing CaO and SiO2, the formation of katoite was found.


2017 ◽  
Vol 35 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Leigang Miao ◽  
Biming Shi ◽  
Nawrat Stanislaw ◽  
Chaomin Mu ◽  
Kezhen Qi

AbstractFlower-like ZnO microstructures were successfully synthesized via a facile hydrothermal route without using any surfactants. The morphology of these microstructures can be easily controlled by adjusting the pH of the reaction solution. The possible growth mechanism of ZnO hierarchical microstructures was proposed based on the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) results. The photocatalytic activity studies of ZnO nanocrystals demonstrated their excellent photocatalytic performance in degrading aqueous methylene blue (MB) under UV-A light irradiation. This higher photocatalytic activity of the ZnO nanoplates was mainly attributed to the exposed facets with the higher surface energy.


2014 ◽  
Vol 881-883 ◽  
pp. 1003-1006
Author(s):  
Zhan Shou Yang ◽  
Mi Xiang Qi ◽  
Shu Ya Wang

strontium carbonate nanopowder materials were synthesized using Sr(OH)2 and Na2CO3 or CO2 as starting materials in the water by ultrasonic irradiation at 3h,and adding suitable amount of EDTA morphology agent.samples were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) through separating strontium oxide solution slurry through by centrifuge , washing strontium carbonate slurry by ethanol.XRD and SEM showed that These products were found to be orthorhombic and spherical nanometer strontium carbonate and to be explained the growth mechanism of nano strontium carbonate powder.


2011 ◽  
Vol 117-119 ◽  
pp. 870-872
Author(s):  
Shi Cai Cui ◽  
Zhao Bo Meng

Calcium silicate for filling material used in dissolved acetylene cylinders was prepared by adding alum as additive. Samples were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The effects of alum on the bleeding, shrinkage, strength, porosity, morphology and phase composition were studied. The experimental results show that the adding of alum can improve the comprehensive performance of samples. The mechanism was discussed in detail.


Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1435
Author(s):  
Olev Vinn

Aragonite plays an important role in the biomineralization of serpulid polychaetes. Aragonitic structures are present in a wide range of serpulid species, but they mostly belong to one clade. Aragonitic structures are present in a wide range of marine environments, including the deep ocean. Aragonitic tube microstructures were studied using a scanning electron microscope. X-ray powder diffraction was used to identify the aragonite. Aragonite is used to build five different types of microstructures in serpulid tubes. The most common aragonitic irregularly oriented prismatic structure (AIOP) is also, evolutionarily, the most primitive. Some aragonitic microstructures, such as the spherulitic prismatic (SPHP) structure, have likely evolved from the AIOP structure. Aragonitic microstructures in serpulids are far less numerous than calcitic microstructures, and they lack the complexity of advanced calcitic microstructures. The reason why aragonitic microstructures have remained less evolvable than calcitic microstructures is currently unknown, considering their fit with the current aragonite sea conditions (Paleogene–recent).


2022 ◽  
Author(s):  
RongMin Cheng ◽  
Conghong Zhan ◽  
Juanjuan Gao

Using Ni foam as a template, Mn0.6Ni0.4CO3 nanosheet assembles were synthesized by hydrothermal method and calcination treatment. X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Inductively...


Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
János Kovács ◽  
Éva Farics ◽  
Péter Szabó ◽  
István Sajó

In sedimentary rocks, Fe-Al phosphate minerals occur in different rocks and depositional environments. Herein, we present microcrystals of wavellite, crandallite, and cacoxenite from pedogenic goethite pisoliths and nodules. Pisoliths and nodules are generally dominated by Fe oxides and oxihydroxides. Frequently, pisoliths and nodules demonstrate high phosphatization and a substantial contribution of allogenic detritus. The aim of our study is to present these remarkable crystals found in goethites. We describe the geochemistry and mineralogy of the pisoliths and try to interpret the possible paragenesis of the minerals. Loose ferruginous pisoliths and nodules are separated from the red paleosol and analyzed using field emission scanning electron microscope (FE-SEM) coupled with the energy dispersive X-ray detector (EDS), X-ray fluorescence spectroscopy (XRF), and X-ray powder diffraction (XRD) methods. The studied paleosols are weathered in a subtropical climate and the newly formed precipitation products, such as crandallite, wavellite, cacoxenite, and goethite, accumulate during the weathering of apatite.


2020 ◽  
Vol 7 (1) ◽  
pp. 500-509
Author(s):  
Mahsuri Yusof ◽  
Nur Tahirah Razali ◽  
Nicholas H. T. Kuan ◽  
Dexter Sigan John

The objectives of this research are to determine the element and polymorph of Polymesoda bengalensis shell and to compare its result with other bivalve shells. The polymorph of the powder was identified by X-ray powder diffraction (XRD) and its morphology was observed through scanning electron microscope (SEM). The XRD study revealed that the shell powder consisted entirely of aragonite. The analysis from SEM also revealed that the aragonite was in the form of rod-like crystal. The morphology of sectional, inner and outer surfaces of the shell was scanned using SEM. It was found that the aragonite was arranged in the form of a cross-lamellar structure of various sizes. The elemental content of the shell was examined using energy-dispersive X-ray spectroscopy (EDX). The result showed that CaCO3 in this shell contained large amounts of calcium and carbon.


2013 ◽  
Vol 203-204 ◽  
pp. 48-51
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz

The composites of Al61Cu27Fe12alloys containing quasicrystalline and crystalline phases (CQ composites) were obtained by the Bridgman method. The morphology of composites crystallized with different solidification rates was studied. The solidification rate influence on fibrous reinforcement morphology was analyzed. The microsections for analysis were prepared parallel and perpendicular to the direction of crystallization. The optical and the scanning electron microscope were used for metallographic observation. Obtained composites were examined by X-ray powder diffraction and reflective X-ray topography. The Laue method enabled to conclude that the matrix is singlecrystalline. The different level of structural perfection of reinforcement fibres was presented at various solidification rates.


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