Fabrication and optical properties of NiO/ZnO hierarchical nanostructures

2021 ◽  
Vol 15 (1) ◽  
pp. 45-50
Author(s):  
Minh Vuong Nguyen ◽  
◽  
Ngoc Khoa Truong Nguyen ◽  
Keyword(s):  
Open Space ◽  
Visible Region ◽  
Hexagonal Structure ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
Hierarchical Nanostructures ◽  
X Ray ◽  
Electrospinning Method ◽  
Zno Nanofibers

NiO/ZnO hierarchical nanostructures were synthesized by a combination of electrospinning, hydrothermal and ultraviolet (UV)-assisted deposition. Initially, ZnO nanofibers were synthesized by electrospinning method following thermal oxidation. Subsequently, ZnO hierarchical nanostructures were synthesized by hydrothermal method using ZnO nanofibers as templates. Finally, NiO nanoparticles were deposited on ZnO surface by UV-assisted deposition method. Morphology and characteristics of the material were determined by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS) and photoluminescence spectrum (PL). The results showed that the NiO/ZnO hierarchical nanostructures with high open space were obtained. NiO/ZnO crystals showed hexagonal structure of ZnO without phase formation of NiO. PL spectra of the NiO/ZnO material showed emission peaks shift towards longer wavelengths in the visible region with increasing the content of NiO nanoparticles.

Methanol Sensing Properties of Electrospun SnO2 -ZnO Nanofibers

2011 ◽  
Vol 356-360 ◽  
pp. 565-568
Author(s):  
Shao Hong Wei ◽  
Mei Hua Zhou ◽  
Wei Ping Du
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Promoting Effect ◽  
Heterojunction Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Scanning Electron

Pure ZnO and SnO2-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO2-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO2/ZnO heterojunction structure. The methanol sensing mechanism of SnO2-ZnO nanofibers were also discussed.

Method for synthesizing ZnO of different nanostructures by electrospinning and study of their gas sensing properties

2019 ◽  
Vol 33 (25) ◽  
pp. 1950297
Author(s):  
Xiang-Bing Li ◽  
Shu-Yi Ma ◽  
Fu-Rong Li ◽  
Yu-Xiang Zhao ◽  
Xiao-Bin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Gas Sensing Properties ◽  
Zno Nanofibers ◽  
Scanning Electron

The properties of nanomaterials usually depend on their microstructures, the same material of different microstructures could be used for various applications. However, most devices could only synthesize a single microstructure, so it is meaningful that the different microstructures were synthesized by one method. In our study, electrospinning was applied to fabricate ZnO nanofibers and nanoparticles. In this approach, Zn(Ac)/PVP composite fibers of different component ratio were synthesized by electrospinning method which was subsequently calcined and formed ZnO nanofibers and nanoparticles. The microstructure, chemical composition and gas sensing were investigated with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and WS-60A gas sensing measurement system. The synthesis mechanisms of ZnO nanofibers and nanoparticles were discussed in detail.

scholarly journals On-chip ZnO nanofibers prepared by electrospinning method for NO2 gas detection

2018 ◽  
Vol 27 (4) ◽  
pp. 317 ◽  
Author(s):  
Van Hoang Nguyen ◽  
Van Dung Nguyen ◽  
Quang Dat Do ◽  
Thi Minh Nguyet Quan ◽  
Manh Hung Chu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
X Ray ◽  
Electrospinning Method ◽  
Resistance Modulation ◽  
Zno Nanofibers ◽  
On Chip ◽  
Gas Response

In the present study, on-chip ZnO nanofibers were fabricated by means of the electrospinning technique followed by a calcination process at 600 oC towards the gas sensor application. The morphology, composition, and crystalline structure of the as-spun and annealed ZnO nanofibers were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD), respectively. The findings show that spider-net like ZnO nanofibers with a diameter of 60 – 100 nm were successfully synthesized without any incorporation of impurities into the nanofibers. The FESEM images also reveal that each nanofiber is composed of many nanograins. The combination of experimental and calculated X-ray diffraction data indicate that ZnO nanofibers were crystallized in hexagonal wurtzite structure. For the gas sensing device application, the ZnO nanofibers-based sensors were tested with the nitrogen dioxide gas in the temperature range of 200 oC to 350 oC and concentrations from 2.5 ppm to 10 ppm. The sensing property results indicate that at the optimal working temperature of 300 oC, the ZnO nanofibers-based sensors exhibited a maximum response of 30 and 166 times on exposure of 2.5 and 10 ppm NO2 gas, respectively. The presence of nanograins within nanofibers, which results in further intensification of the resistance modulation, is responsible for such high gas response.

scholarly journals Fabrication of Electrochemical Electrodes Based on Platinum and \(\text{ZnO}\) Nanofibers for Biosensing Applications

2017 ◽  
Vol 27 (3) ◽  
pp. 221 ◽  
Author(s):  
Dang Thi Thanh Le ◽  
Nguyen Van Hoang ◽  
Nguyen Van Hieu ◽  
Vu Quang Khue ◽  
Tran Quang Huy
Keyword(s):  
Average Length ◽  
Surface Characteristics ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
X Ray ◽  
Screen Printed Electrodes ◽  
Pt Electrodes ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Screen Printed

Platinum (Pt) electrodes were designed in imitation of screen-printed electrodes, and prepared by microelectronic techniques. These electrodes were then modified with zinc oxide (ZnO) nanofibers for biosensing applications. ZnO nanofibers with average length \( \sim 20-30\; \mu\) m and diameter \(\sim 150\) nm in hexagonal crystalline structure are prepared using electrospinning method. Their surface characteristics were analyzed by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Electrochemical properties of modified Pt electrodes were investigated in comparison with commercial carbon screen-printed electrodes. The results showed that the cyclic voltammogram of modified Pt electrodes was stable, but has much lower resistance compared to that of carbon screen-printed electrodes.

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

scholarly journals Enhanced Photocatalytic Activity of Cu2O Cabbage/RGO Nanocomposites under Visible Light Irradiation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermo Gravimetric Analysis ◽  
Visible Region ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Pollutants ◽  
Transmission Electron

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

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