Flowery Ni Microcrystals Consisting of Star-shaped Nanorods: Facile Synthesis, Formation Mechanism and Magnetic Properties

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.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Heriyanto Tinentang ◽  
Henry F Aritonang ◽  
Harry S. J. Koleangan

Telah dilakukan penelitian tentang kemampuan aktivitas anti bakteri untuk bakteri Staphylococcus aureus (gram positif) dan Escherichia coli (gram negatif) dengan menggunakan nanokomposit nata de coco/TiO2, nata de coco/Ag, dan nata de coco/TiO2/Ag dengan variasi konsentrasi Ag 0,5 M; 0,6 M; 0,7 M; 0,8 M dan 0,9 M  menggunakan metode reduksi kimia. Nanopartikel tersebut dikarakterisasi menggunakan X-Ray Diffractometry (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy  (SEM-EDS) dan anti bakteri. Untuk uji aktivitas antibakteri menggunakan metode kertas cakram dan dilakukan sebanyak dua kali ulangan untuk tiap-tiap sampel dan bakteri yang diuji. Hasil penelitian menunjukan, aktivitas anti bakteri nanokomposit yang paling baik dalam menghambat pertumbuhan bakteri adalah nanokomposit Nata de coco/TiO2/Ag mampu menghambat pertumbuhan bakteri Escherichiacoli dan Staphylococcusaureus, namun nanokomposit tersebut lebih efektif menghambat pertumbuhan bakteri Escherichiacoli.ABSRACT Research on the ability of anti-bacterial activity for Staphylococcus aureus (gram positive) and Escherichia coli (gram negative) bacteria using nata de coco / nanocomposites TiO2, nata de coco / Ag, and nata de coco / TiO2 / Ag with variations of Ag 0,5 M; 0.6 M; 0.7 M; 0.8 M and 0.9 M using the chemical reduction method. Nanoparticles were characterized using X-Ray Diffractometry (XRD), scanning electron microscopy-energy dispersive X-ray spctroscopy  (SEM-EDS) and anti-bacterial actvity. Test the antibacterial activity using the paper disc method and repeated two times for each sample and bacteria tested. The results showed that the good anti-bacterial activity of nanocomposites in inhibiting bacterial growth was nanocomposite nata de coco /TiO2/Ag  able to inhibit the growth of Escherichia coli and S. aureus, but the nanocomposite is more effective in inhibiting the growth of Escherichia  coli bacteria.


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.


2018 ◽  
Vol 14 (8) ◽  
pp. 155014771879075 ◽  
Author(s):  
Khurram Shehzad ◽  
Nazar Abbas Shah ◽  
Muhammad Amin ◽  
Murrawat Abbas ◽  
Waqar Adil Syed

Synthesis of one-dimensional nanostructures, such as nanowires, is of vigorous significance for achieving the desired properties and fabricating functional devices. In this work, we report the synthesis of tin oxide (SnO2) nanowires on gold-catalyzed silicon substrate by carbothermal reduction process. SnO2 nanowires were synthesized with SnO2 and graphite powders as the source materials at atmospheric pressure and temperature of 900°C in the ambience of nitrogen (N2) gas. First, the effect of source material ratio SnO2:C on growth of SnO2 nanowires was studied. The structural, morphological and compositional properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The scanning electron microscopy investigation reveals that uniform dense nanowires of SnO2 (diameter ~127 nm and length ~40 µm) were synthesized with vapour–liquid–solid mechanism. Ultraviolet–visible spectra estimate that the optical band gap of the synthesized SnO2 nanowires was 3.72 eV. Second, the gas sensing performance of synthesized SnO2 nanowires was investigated by testing with carbon monoxide (CO), Methane (CH4) and methanol (CH3OH) gases at different operating temperatures and concentrations. Results indicate that the synthesized SnO2 nanowires are highly promising for gas sensing applications.


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.


2016 ◽  
Vol 852 ◽  
pp. 346-348
Author(s):  
Hong Cai ◽  
Qing Bo Du ◽  
Ji Gui Xu ◽  
Hong Wei Shi ◽  
Jun Zhu

a-Fe2O3 nanorods over large areas were successfully synthesized by hydrothermal method, using FeCl3 as iron source and PVP as surfactant. The as-synthesized a-Fe2O3 nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and magnetic measurement system (SQUID-VSM) . The results show that the nanorods prepared by hydrothermal method with the diameter of about 70 nm and the length of about 300 nm. The magnetic properties of the synthesized nanorods were studied, and the remnant magnetization and coercivity of the α-Fe2O3 nanorods at 300K are found to be 0.07emu/g and 2300Oe, respectively. The a-Fe2O3 nanorods reported here may have opportunities for both fundamental research and technological applications.


2020 ◽  
Vol 31 (8) ◽  
pp. 1367-1384 ◽  
Author(s):  
C Karthikeyan ◽  
R Dhilip Kumar ◽  
J Anandha Raj ◽  
S Karuppuchamy

Metal sulfides received key interest as an electrode material for storage and conversion of energy. Here, the novel nanostructured N17S18 and (CoNi)3S4 materials were synthesized via one-step hydrothermal method, and the synergistic effect of metal ions and electrochemical properties was investigated. A new and simple solution growth technique was employed in this work. The prepared nanopowders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy techniques. The X-ray diffraction analysis of the prepared nanopowder revealed the formation of cubic phase cobalt nickel sulfides (CoNi)3S4 and hexagonal phase nickel sulfides (Ni17S18). Scanning electron microscopy analysis display fibrous, flakes and sheet-like morphology for CoxSx, N17S18 and (CoNi)3S4, respectively. Fibrous and sheet-like morphology exhibits higher electrochemical performance in supercapacitors. The electrochemical behavior of the amorphous CoxSx, crystallite Ni17S18 and (CoNi)3S4 modified electrodes was investigated using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge techniques. The specific capacitance of 57 F/g and 31 F/g were obtained for the amorphous CoxSx and crystalline (CoNi)3S4 powder, respectively. Amorphous CoxSx modified electrode retains 76% of initial capacitance after 1000 repeated cycling process. These results of this study suggest that the CoxSx and crystalline (CoNi)3S4 are appropriate materials for supercapacitor applications.


2014 ◽  
Vol 938 ◽  
pp. 46-51 ◽  
Author(s):  
M. Nazri Abu Shah ◽  
S. Hanim Md Nor ◽  
Kamariah Noor Ismail ◽  
Abdul Hadi

A series of CexZr(1-x)O2 mixed oxides with different ratio (0 x 1) have been synthesized using microemulsion method. The structure and morphology of the mixed oxides have been investigated via X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The results showed that the synthesized mixed oxides were of nanoscale size and the cubic phase was obtained with the application of a ratio of x > 0.5. Additionally, it was found that the tetragonal phase existed with lower ceria content. The average crystallite size of the CexZr(1-x)O2 series were found to be in the 5 - 10 nm range. Moreover, the roughness of these mixed oxides had also decreased with increasing ceria content.


2014 ◽  
Vol 953-954 ◽  
pp. 995-998 ◽  
Author(s):  
Shuo Wang ◽  
Yi Chen Li ◽  
Chao Song ◽  
En Zhou Liu ◽  
Jun Fan

Plasmonic Au decorated TiO2 nanosheet film was firstly prepared by the combination of a hydrothermal method and a microwave-assisted chemical reduction process. The prepared sample was characterized by scanning electron microscopy (SEM), UV-vis absorption spectrum (UV-vis) and photoluminescence spectrum (PL) respectively. Results show that Au nanoparticles with narrow distribution are uniformly loaded on the nanosheet surface, and the resulted composite nanostructure exhibits distinct surface plasmon absorption and quenched photoluminescence compared to pure TiO2 nanostructure. Photocatalytic tests show that Au decorated TiO2 exhibits enhanced photocatalytic activity for photocatalytic reduction of CO2 to methanol.


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.


2019 ◽  
Vol 18 (02) ◽  
pp. 1850021 ◽  
Author(s):  
Khawla S. Khashan ◽  
Sarah F. Abbas

Indium nitride InN nanoparticles NPs suspension prepared by Nd:YAG laser ablation of indium target submerged under ammonium hydroxide. The Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV/VIS/NIR spectrophotometer and Conductivity meter were used to determine the properties of the nanoparticles prepared with different laser conditions. Fourier transform infrared spectra exhibit the presence of In[Formula: see text]N and In–N bonds, which indicates the formation of InN particles. X-ray diffraction pattern observed in the formation of InN NPs with cubic phase, the average diameters of the dominant peak c-InN (101) were approximately 2[Formula: see text]nm. Scanning electron microscopy image shows the presence of a large number of spherical shape nanoparticles having a particle size in the range 2–40[Formula: see text]nm with a few individual nanoparticles larger than 128[Formula: see text]nm. The transmission spectra of InN NPs suspension have the maximum optical transmission edge at 1378[Formula: see text]nm with bandgap energy was 0.85–1.2[Formula: see text]eV. InN has high electrical conductivity that depends on temperature value with small activation energy at room temperature ranging from 0.0318[Formula: see text]meV to 0.1591[Formula: see text]meV.


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