Facile synthesis and electrical characteristics of n-SnO2/p-NiO nanowire heterojunctions

2019 ◽  
Vol 29 (1) ◽  
pp. 77 ◽  
Author(s):  
Dang Thi Thanh Le ◽  
Chu Manh Hung
Keyword(s):  
Average Length ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Energy Structure ◽  
Pure Sno2 ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
Xrd Patterns ◽  
Hydrothermal Methods ◽  
Nanowire Heterojunctions

In the current work, we report a facile synthesis of n-SnO2/p-NiO nanowire heterojunctions by a drop-coating approach. The pure SnO2 and NiO nanowires (NWs) were grown by chemical vapor deposition (CVD) and hydrothermal methods, respectively. Morphology, composition and crystal structures of the NWs and heterojunctions were investigated by means of field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The data showed that SnO2 NWs were grown with their average diameter of 200 nm and length of about 10 mm. The NiO NWs were also synthesized with a shorter average length and smaller average diameter compared to those of the SnO2 NWs. The EDS results indicated no impurity present in both SnO2 and NiO NWs. The XRD patterns pointed out the tetragonal rutile and cubic structures of SnO2 and NiO, respectively. Interestingly, electrical properties of the NWs and heterojunctions were studied through the Keithley 2602A sourcemeter-based I-V characterizations. The results confirm the nature of the metal semiconducting oxides. The formation of the n-SnO2/p-NiO heterojunctions was certified through the rectifying behavior of the I-V curves with the rectification ratio of about 5 at ± 3V and 350 oC. The potential energy barrier between the NWs was also estimated to be about 1.16 eV. The band energy structure was also proposed to get insight into characteristics of the n-SnO2/p-NiO heterojunction.

Highly Porous Hydroxyapatite Ceramics for Engineering Applicatios

2010 ◽  
Vol 63 ◽  
pp. 408-413 ◽  
Author(s):  
Hrvoje Ivankovic ◽  
Sebastijan Orlic ◽  
Dajana Kranzelic ◽  
Emilija Tkalcec
Keyword(s):  
Average Length ◽  
Average Diameter ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
Gas Cell ◽  
Porous Hydroxyapatite ◽  
Hydroxyapatite Ceramics ◽  
Heat Treated ◽  
Hydrothermal Transformation ◽  
Highly Porous

Highly porous hydroxyapatite (Ca10(PO4)6(OH)2, HA) was prepared through hydrothermal (HT) transformation of aragonitic cuttlefish bones (Seppia Officinalis L. Adriatic Sea) in the temperature range from 140°C to 220°C for 20 minutes to 48 hours. Mechanism of hydrothermal transformation of bones was investigated by DTA/TG analyzer coupled online with FTIR spectrometric gas cell equipment (DTA-TG-EGA-FTIR analysis), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). DTA-TG-EGA-FTIR analysis have shown the release of CO2 at about 400°C, 680°C and 990°C. The first release could be attributed to organics not completely removed from the heat treated bones, and the second release to decomposition of unconverted aragonite, whereas, the third one could be attributed to CO3 2– groups incorporated in the structure of HA. The interconnecting porous morphology of the starting material (aragonite) was maintained during the HT treatment. The formation of dandelion-like HA spheres with diameter from 3 to 8 μm were observed, which further transformed into nanoplates and nanorods with an average diameter of about 200-300 nm and an average length of about 8-10 μm.

Structural and Optoelectronic Properties of Single Crystalline SnO2:Ga Films Deposited on α-Al2O3 (0001) by MOCVD

2009 ◽  
Vol 79-82 ◽  
pp. 763-766
Author(s):  
Xu An Pei ◽  
Feng Ji ◽  
Jin Ma ◽  
Ti Ning ◽  
Zhen Guo Song ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Optoelectronic Properties ◽  
Visible Range ◽  
Pure Sno2 ◽  
Rutile Structure ◽  
Single Crystalline ◽  
Crystalline Films ◽  
Xrd Patterns ◽  
Α Al2o3 ◽  
Structural And Optoelectronic Properties

12% Gallium-doped tin oxide (SnO2:Ga) single crystalline films have been prepared on α-Al2O3 (0001) substrates by the metalorganic chemical vapor deposition (MOCVD) method. The grown temperatures were varied from 400 to 600°C. According to XRD patterns, the film deposited at 500°C has the best single crystalline structure. Subsequently, 3 to 15% doped films were fabricated at 500°C using the same method, except that Gallium organometallic (OM) source was injected in pulsed-mode for the 3, 5 and 10% -doped films. Then, structural and optoelectronic properties of the films were investigated in detail. The obtained films all have the rutile structure of pure SnO2. Film with resistivity of 1.09×10−2Ω cm, carrier concentration of 8.86×1019cm−3 and Hall mobility of 6.49cm2 v−1 s−1 was obtained at 5% of Ga concentration. The average transmittance for the SnO2:Ga films in the visible range were over 90%.

scholarly journals Preparation of Silver Nanostructures from Bicontinuous Microemulsions

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Pedroza-Toscano ◽  
M. Rabelero-Velasco ◽  
R. Díaz de León ◽  
H. Saade ◽  
R. G. López ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Average Length ◽  
Sodium Dodecylsulfate ◽  
Average Diameter ◽  
Silver Nanostructures ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Reverse Microemulsions

Precipitation of silver nanoparticles at 70°C was carried out by dosing a 1.3 M sodium borohydride aqueous solution over bicontinuous microemulsions formed with a mixture of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium dodecylsulfate (SDS) as surfactants, a 0.5 M silver nitrate aqueous solution, and toluene. Weight ratios of 2.5/1 and 3/1 AOT/SDS were used in the precipitation reactions. Silver nanoparticles were characterized by transmission electronic microscopy, X-ray diffraction, and atomic absorption spectroscopy. A mixture of isolated spheroidal nanoparticles (≈15 wt.%) with an average diameter around 10 nm and wormlike structures (≈85 wt.%) with an average length close to 480 nm and an average diameter ca. 40 nm was obtained, regardless of the AOT/SDS ratio. Higher yields were obtained compared with those reported when reverse microemulsions were employed. Formation of wormlike structures was ascribed to one-dimensional aggregation of crystal and particles within the channels of bicontinuous microemulsions, which performed as templates.

Preparation and Characterization of Needle-Like ZnO on TiO2 Nanoparticles by Solution-Immersion Method and RF Magnetron Sputtering

2013 ◽  
Vol 832 ◽  
pp. 596-601 ◽  
Author(s):  
N.A.M. Asib ◽  
Aadila Aziz ◽  
A.N. Afaah ◽  
Mohamad Rusop ◽  
Zuraida Khusaimi
Keyword(s):  
Magnetron Sputtering ◽  
Average Diameter ◽  
Rf Magnetron Sputtering ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
X Ray ◽  
Xrd Patterns ◽  
Average Size

Needle-like zinc oxide (ZnO) nanostructures was deposited on titanium dioxide (TiO2) nanoparticles by solution-immersion method and Radio Frequency (RF) magnetron sputtering with diffferent RF powers, respectively on a glass substrate to synthesis nanocomposites of ZnO/TiO2. Field Emission Scanning Electrons Microscope (FESEM) images demonstrate that needle-like ZnO (112-1110 nm) are deposited on the surface of the TiO2nanoparticles with the diameter of approximately 36.3-62.9 nm. At 200 W, more needle-like ZnO with smallest average diameter (112 nm) appeared on the TiO2nanoparticles, which also has the smallest average size of 36.3 nm The compositions of elements in the nanocomposites were showed by Energy Dispersive X-ray Spectrometry (EDX). All elements of Ti, O, and Zn are observed as major components which confirm the presence of TiO2and ZnO in the composite. X-ray Diffraction (XRD) patterns of the nanocomposites show ZnO formed on TiO2nanoparticles are hexagonal with a wurtzite structure and it revealed ZnO/TiO2thin films were succesfully deposited as nanocomposites of ZnTiO3at 100 W,Zn2TiO4at 150 W and Zn2Ti3O8at 200 W and above.

Magnetic Properties of Mg0.4Ca0.6Fe2O4 Nanoparticles Synthesized by Sol-Gel Method for Hyperthermia Treatment

2014 ◽  
Vol 631 ◽  
pp. 193-197
Author(s):  
A.M. Escamilla-Pérez ◽  
D.A. Cortés-Hernández ◽  
J.M. Almanza-Robles ◽  
D. Mantovani ◽  
P. Chevallier
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Different Temperatures ◽  
Xrd Patterns

Powders of Mg0.4Ca0.6Fe2O4were prepared by sol-gel using ethylene glycol and Mg, Ca and Fe nitrates as starting materials. Those powders were heat treated at different temperatures (300, 400, 500 and 600 °C) for 30 min. The materials obtained were characterized by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The Ca-Mg ferrite with the most appropriate magnetic properties was further analyzed by transmission electron microscopy (TEM). The heating capability of the nanoferrites was also tested via magnetic induction. The XRD patterns of these Ca-Mg ferrites showed a cubic inverse spinel structure. Furthermore, neither traces of hematite nor orthorhombic Ca ferrite phases were detected. Moreover, all the Ca-Mg ferrites are superparamagnetic and the particle size distribution of these Ca-Mg magnetic nanoparticles exhibits an average diameter within the range of 10-14 nm. The needed temperature for hyperthermia treatment was achieved at around 12 min.

Chemically Synthesized Hierarchical Flower like ZnO Microstructures

2019 ◽  
Vol 233 (8) ◽  
pp. 1183-1200 ◽  
Author(s):  
V. L. Patil ◽  
S. A. Vanalakar ◽  
S. A. Vhanalakar ◽  
A. S. Kamble ◽  
T. D. Dongale ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Average Diameter ◽  
Zno Thin Films ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Hexagonal Wurtzite Crystal Structure ◽  
Xrd Patterns ◽  
Hexagonal Wurtzite Crystal

Abstract In the present study, we have deposited hierarchical flower-like microstructured zinc oxide (ZnO) thin films directly on a glass substrate by using the simplistic aqueous chemical route for different concentrations of triethanolamine (TEA) which acted like a complexing agent. The as-synthesized ZnO thin films were subsequently annealed at 300 °C and are characterized with characterization techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL), and electrical resistivity. The hexagonal wurtzite crystal structure of as-synthesized ZnO thin films was confirmed by their XRD patterns and the well-resolved ZnO flowers-like morphology was revealed from the FESEM micrographs. From FESEM images it can be seen that the ZnO flower is composed of dozens of nanorods originating from the same core in a symmetric fashion with an average diameter of around 180-300 nm. The flower-like morphology was obtained at 0.3 M TEA concentration. Due to its hierarchical structure, the deposited ZnO thin films were employed for multiple applications such as gas sensing and anti-microbial activity. The ZnO thin films with micro-flowers like morphology showed the maximum gas sensor sensitivity ∼64.50 at 150 °C for 100 ppm of NO2 gas. Moreover, the bacteria were completely destroyed in the presence of as-deposited ZnO thin films.

ARC Discharge for the Synthesis of Monoclinic Ga2O3 Nanowires

1999 ◽  
Vol 581 ◽  
Author(s):  
Young Chul Choi ◽  
Dong Jae Bae ◽  
Seung Mi Lee ◽  
Young Soo Park ◽  
Young Hee Lee ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Arc Discharge ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Crystalline Nature ◽  
Twin Defects ◽  
Xrd Patterns ◽  
Gallium Oxides ◽  
Ft Raman

ABSTRACTMonoclinic gallium oxide (β-Ga2O3) nanowires were catalytically synthesized by electric arc discharge of GaN powders mixed with a small amount (less than 5 %) of transition metals under a pressure of 500 Torr (80 %-Ar + 20 %-O2). Scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images showed that the average diameter of the wires were about 30 nm and their lengths were as long as up to one hundred micrometer, resulting in extremely large aspect ratio. Fourier diffractogram was indicative of single crystalline nature of the β-Ga2O3 wire. HRTEM image also showed β-Ga2O3 with twin defects at the center of the wire which might play as nucleation seeds. Both X-ray diffraction (XRD) patterns and FT-Raman spectra of the wires identified the observed nanowires as monoclinic crystalline gallium oxides.

scholarly journals Chemical Vapor Deposited Mixed Metal Halide Perovskite Thin Films

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3526
Author(s):  
Siphesihle Siphamandla Magubane ◽  
Christopher Joseph Arendse ◽  
Siphelo Ngqoloda ◽  
Franscious Cummings ◽  
Christopher Mtshali ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Coverage ◽  
Chemical Vapor ◽  
Reaction Chamber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cvd Method ◽  
Metal Halide Perovskite ◽  
Chemical Vapor Deposited ◽  
Xrd Patterns

In this article, we used a two-step chemical vapor deposition (CVD) method to synthesize methylammonium lead-tin triiodide perovskite films, MAPb1−xSnxI3, with x varying from 0 to 1. We successfully controlled the concentration of Sn in the perovskite films and used Rutherford backscattering spectroscopy (RBS) to quantify the composition of the precursor films for conversion into perovskite films. According to the RBS results, increasing the SnCl2 source amount in the reaction chamber translate into an increase in Sn concentration in the films. The crystal structure and the optical properties of perovskite films were examined by X-ray diffraction (XRD) and UV-Vis spectrometry. All the perovskite films depicted similar XRD patterns corresponding to a tetragonal structure with I4cm space group despite the precursor films having different crystal structures. The increasing concentration of Sn in the perovskite films linearly decreased the unit volume from about 988.4 Å3 for MAPbI3 to about 983.3 Å3 for MAPb0.39Sn0.61I3, which consequently influenced the optical properties of the films manifested by the decrease in energy bandgap (Eg) and an increase in the disorder in the band gap. The SEM micrographs depicted improvements in the grain size (0.3–1 µm) and surface coverage of the perovskite films compared with the precursor films.

Rietveld Analysis of Aurivillius-Type Structure Ceramics Synthesized from Precursors Prepared by Classical and HEBM Methods

2013 ◽  
Vol 203-204 ◽  
pp. 319-322
Author(s):  
Jolanta Dercz ◽  
Grzegorz Dercz ◽  
Krystian Prusik ◽  
Rafał Babilas
Keyword(s):  
Single Phase ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
High Energy ◽  
Energy Structure ◽  
X Ray Diffraction ◽  
Network Parameters ◽  
Porcelain Mortar ◽  
Xrd Patterns ◽  
Xrd Method

The aim of this study was to analyze the influence of the method of preparing the substrates in the form of simple oxides for the structure of the final Bi5Ti3FeO15ceramics. Milling of the substrates was carried out by two methods: the classical one by hand mixing in a porcelain mortar, and by high-energy. Structure studies were performed by the X-ray diffraction (XRD) method. XRD patterns were analyzed with the Rietveld method using the DBWS 9807a program. It was found out that the slightest deviation of the network parameters from the catalog data occurs for the sample obtained from simple oxides by free sintering (BTFs). Furthermore, it was also determined that the optimal high-energy time of the substrates is 5 hours. When compared to the ICDD catalog data, the resulting ceramics is a single phase one and has the lowest network parameters deviation among all samples which were subject to high-energy.

scholarly journals Tunable synthesis of platinum nanoparticles by EtOH reduction in presence of poly (vinylpyrrolidone)

2015 ◽  
Vol 50 (2) ◽  
pp. 87-92 ◽  
Author(s):  
MS Rahman ◽  
S Akhter ◽  
KN Ahmed ◽  
MS Rahman ◽  
RK Saha ◽  
...  
Keyword(s):  
Platinum Nanoparticles ◽  
Average Molecular Weight ◽  
Average Diameter ◽  
Organic Polymer ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Uv Visible ◽  
Xrd Patterns ◽  
Growth Formation

Monodispersed platinum nanoparticles (Pt-NPs) with an average diameter dTEM 3.1±1.0 nm were synthesized by EtOH reduction method in the presence of an organic polymer poly (vinylpyrrolidone) (PVP) with an average molecular weight of 40,000. Using this particles as seed, size tunable Pt-NPs of dTEM 3.1±1.0 nm to 5.7±1.6 nm with sufficient monodispersity were synthesized by multiple step seeding growth. Formation of Pt-NPs was confirmed by the UV-visible absorption spectra. Transmission electron micrographs (TEM) and powder X-ray diffraction (XRD) patterns confirmed that the particles were single crystalline with fcc crystal geometry.Bangladesh J. Sci. Ind. Res. 50(2), 87-92, 2015

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