Effect of Hydrothermal Reaction Conditions on the Sizes and Morphologies of ZnO Nanorods

2013 ◽  
Vol 765-767 ◽  
pp. 3170-3175 ◽  
Author(s):  
Jian Jiao Zhang ◽  
Hong Yan Yue ◽  
Er Jun Guo ◽  
Li Ping Wang ◽  
Chun Yu Zhang ◽  
...  
Keyword(s):  
Hydrothermal Reaction ◽  
Zno Nanorods ◽  
Influence Factors ◽  
Particle Morphology ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Hydrothermal Temperature ◽  
Zno Nanostructure ◽  
Temperature Time

The influence factors of hydrothermal treatment on the formation process of ZnO nanorods are investigated involving with hydrothermal temperature, time and precursor concentration. The as-obtained products were characterized by Scanning Electron microscope (SEM) and X-ray diffraction (XRD), respectively. XRD result indicates that the obtained ZnO nanorods are high-quality single crystals. SEM results indicate that both the diameter and the length of ZnO nanorods increase with increasing the hydrothermal time and temperature. The precursor concentration prominently determines the morphologies of ZnO nanostructure from initial particle morphology to rod-like, and to final slice-like morphology.

Evolution of Crystalline Phase and Morphology of the Products Formed during the Hydrothermal Synthesis of Y2O3 Powders

2011 ◽  
Vol 189-193 ◽  
pp. 1275-1279
Author(s):  
Ying Wang ◽  
Gao Yang Zhao ◽  
Li Yuan
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Treatment ◽  
Crystalline Phase ◽  
Hydrothermal Reaction ◽  
Yttrium Nitrate ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron

The crystalline phase and morphology of the products formed during the synthesis of yttrium oxide via the hydrothermal treatment yttrium nitrate were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Products with high OH/NO3ratios are formed with the increasing of hydrothermal treatment. The crystalline phases are evolved from Y2(OH)5.14(NO3)0.86•H2O toY4O(OH)9(NO3) and finally Y(OH)3. The hydrothermal reaction conditions play an important role in the synthesis of the microstructures. Results show the particle size and final morphology of samples could be controlled by reaction temperature, reaction time, and OH-concentration. Sheets, hexagonal and needle-like Y2O3powders are obtained with the hydrothermal treatment of yittrium nitrate at 180 oC to 200oC for 2-8 hours at pH 9-13.

Preparation and Spectral Properties of PVP-Modified ZnO Nanorods

2008 ◽  
Vol 368-372 ◽  
pp. 329-332 ◽  
Author(s):  
Yang Feng Huang ◽  
Han Ning Xiao ◽  
Shu Guang Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Uv Spectroscopy ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Emission ◽  
Transmission Electron ◽  
Light Region ◽  
Uv Absorption Spectrum

ZnO nanorods were prepared by a hydrothermal reaction in the presence or absence of PVP (polyvinyl pyrrolidone). The obtained products were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, UV-Vis absorption (UV) spectroscopy and photoluminescence (PL) spectroscopy. The results suggest that PVP plays an important role in the preparation of ZnO nanorods. The UV absorption spectrum showed PVP increases the UV-shielding ability but doesn’t influence the transparency in the visible light region. A weak UV emission at 353 nm of PL spectra exhibit the surface of ZnO nanorods is passivated and oxygen-related defects is supplied by PVP.

Study on Tungsten Oxide (WO3) Nanostructures Formation via Seeded Growth Hydrothermal Reaction

2011 ◽  
Vol 83 ◽  
pp. 204-209
Author(s):  
Rabizah Makhsin Siti ◽  
Abdul Razak Khairunisak ◽  
Zainovia Lockman
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Sodium Tungstate ◽  
Hydrothermal Reaction ◽  
Hexagonal Structure ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Seeded Growth ◽  
Seed Formation ◽  
X Ray

This work describes the formation of WO3 nanostructures via seeded growth hydrothermal reaction. WO3 seed formation was first studied using thermal oxidation of W substrate from 300-500°C for 30 minutes. The optimum seeded substrates were then subjected to hydrothermal reaction at 80°C by varying precursor concentration and pH of the solution. Optimum oxidation temperature to produce WO3 seeds was at 400°C for 30 minutes. Below 400°C, no seed was formed while above that temperature the seeds became too compact and less uniform. The optimum hydrothermal reaction parameters were obtained after 24 hrs reaction time, concentration ratio of sodium tungstate dehydrate to cetyltrimethylammonium bromide (CTAB) of 6:1 and at pH 2. By lowering the pH and increasing the precursor concentration, the growth of WO3 nanostructures was enhanced. X-ray diffraction analysis showed that WO3 nanostructures formed were of hexagonal structure.

scholarly journals Fabrication of Mo-Doped WO3 Nanorod Arrays on FTO Substrate with Enhanced Electrochromic Properties

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1627 ◽  
Author(s):  
Bao Wang ◽  
Wenkuan Man ◽  
Haiyang Yu ◽  
Yang Li ◽  
Feng Zheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Response Times ◽  
Hydrothermal Reaction ◽  
Average Diameter ◽  
Nanorod Arrays ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Electrochromic Properties ◽  
Wo3 Nanorod

Well-oriented and crystalline WO3 nanorod arrays (WNRAs) decorated with Mo were synthesized on fluorine doped tin oxide (FTO) substrate by the hydrothermal method. The effects of Mo doping, hydrothermal reaction time, and hydrothermal temperature on the morphologies and electrochromic properties of as-prepared WNRAs were studied thoroughly. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and chronoamperometry techniques were used to characterize the structures and properties of obtained WNRAs. The results demonstrate that the average diameter of the as-prepared WNRAs ranged from 30 to 70 nm. During the decoration of Mo on the WNRAs, the growth density of as-prepared WNRAs decreased and the surfaces became rough. However, the decorated Mo on WNRAs synthesized at 180 °C for 5 h with a Mo/W mole ratio of 1:40 exhibited better electrochromic properties than single WNRAs. They exhibited high optical modulation (61.7%), fast bleaching/coloring response times (3 s/9 s), high coloration efficiency values (73.1 cm2/C), and good cycling stability.

Controllable synthesis, characterization, and electrochemical properties of manganese oxide nanoarchitectures

2008 ◽  
Vol 23 (3) ◽  
pp. 780-789 ◽  
Author(s):  
Lichun Zhang ◽  
Liping Kang ◽  
Hao Lv ◽  
Zhikui Su ◽  
Kenta Ooi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Manganese Oxide ◽  
Manganese Oxides ◽  
Hydrothermal Reaction ◽  
Reaction Times ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
Transmission Electron

Flowerlike manganese oxide microspheres and cryptomelane-type manganese oxide nanobelts were selectively synthesized by a simple decomposition of KMnO4 under mild hydrothermal conditions without using template or cross-linking reagents. The effect of varying the hydrothermal times and temperatures on the nanostructure, morphology, compositional, and electrochemical properties of the obtained manganese oxides was investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies showed that the flowerlike manganese oxide microspheres could be obtained at relatively low hydrothermal temperatures, while high hydrothermal temperatures were favorable for the formation of cryptomelane-type manganese oxide nanobelts. A morphology and crystalline evolution of the nanostructures was observed as the hydrothermal temperature was increased from 180 to 240 °C. On the basis of changing the temperatures and hydrothermal reaction times, the formation mechanism of cryptomelane-type manganese oxide nanobelts is discussed. Cyclic voltammetry (CV) was used to evaluate the electrochemical properties of the obtained manganese oxide nanostructures, and the results show that the electrochemical properties depend on their shape and crystalline structure. This easily controllable, template-free, and environmentally friendly method has the potential for being used in syntheses of manganese oxide nanomaterials with uniform morphologies and crystal structures.

Facile Controlled Synthesis of Manganese Oxide Hierarchical Microspheres by Hydrothermal Method

2011 ◽  
Vol 688 ◽  
pp. 107-115 ◽  
Author(s):  
Dong Yan Li ◽  
Yun Fa Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Hydrothermal Temperature ◽  
Transmission Electron ◽  
Hierarchical Microspheres

MnO2hierarchical microsphere has been synthesized by a facile and direct hydrothermal reaction between KMnO4and HCl without the aids of catalysts, surfactants or templates. The as-prepared microsphere, as characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis and nitrogen adsorption and desorption, is in form of K0.27MnO2(H2O )0.54, with a flower-like hierarchical microsphere structure and a BET surface area value of 52 m2/g. The morphology of the product can be simply tailed by controlled by reaction temperature or period and crystallinity can be modified by changing the concentrate of KMnO4. In general, excessive KMnO4and low hydrothermal temperature are favor to forming flower-like hierarchical structure. Besides, the formation mechanisms of the hierarchical schemes are proposed.

Hierarchical ZnO Nanostructure on Steel Substrate by Electrochemical Deposition

2014 ◽  
Vol 875-877 ◽  
pp. 554-557
Author(s):  
Bao Li Zhang ◽  
X.P. Zou ◽  
X.M. Lv ◽  
G.Q. Yang ◽  
C.L. Wei ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Steel Substrate ◽  
Zno Nanorods ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zno Nanostructure ◽  
Transmission Electron ◽  
Absorption Of Light ◽  
Surface Area Increase

In this paper we use electrochemical deposition to grow a layer of gray compact film on the steel, characterized the product by X-ray diffraction (XRD) we find the ZnO cone-like rods and hierarchical rod-like nanostructure are all preferentially growing along the C-axis, which is confirmed by the direction of crystal growth in the transmission electron microscope (TEM) image. In the TEM image we find the hierarchical ZnO nanorods have an in situ growth in the high-energy electron beam irradiation, which makes the specific surface area increase and to some extent enhance the absorption of light energy.

scholarly journals Garcinia Mangostana Peel Extract as Sustainable Fuel Source on Ceria Synthesis under Hydrothermal Condition

2019 ◽  
Vol 8 (3) ◽  
pp. 255-261
Author(s):  
Salprima Yudha S ◽  
◽  
Morina Adfa ◽  
Aswin Falahudin ◽  
Deni Agus Triawan ◽  
...  
Keyword(s):  
Crystal Size ◽  
Hydrothermal Reaction ◽  
Hydrothermal Condition ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Garcinia Mangostana ◽  
Reaction Conditions ◽  
Xrd Pattern ◽  
X Ray ◽  
Fuel Source

Cerium (IV) oxide or ceria (CeO2) was fabricated by heating an aqueous extract of Garcinia mangostana and cerium (III) nitrate in hydrothermal autoclave reactor at 200 °C for 3 hours, followed by calcination at 600 °C for 5 hours. The powder X-ray diffraction (XRD) pattern of the precipitate from cerium(III) nitrate under hydrothermal reaction conditions shows no clear XRD peaks, indicating its amorphous nature. In contrast, the products from the calcinated samples exhibit XRD peaks, which correspond to cubic fluorite structure with an average crystal size of 7.55 nm. The elemental mapping using the energy-dispersive X-ray (EDX) analysis reveals the main elements present were cerium and oxygen, with minor impurities in low amounts. The presence of Garcinia mangostana extract is predicted to be the key component and fuel source to obtain CeO2 particles with narrow crystal size.

Synthesis of Monodisperse Fe3O4 Microspheres and Effect of the Precursor Concentration

2011 ◽  
Vol 183-185 ◽  
pp. 2327-2330 ◽  
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Ming Xing Han
Keyword(s):  
Room Temperature ◽  
Size Range ◽  
Precursor Concentration ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Xrd Pattern ◽  
X Ray ◽  
Magnetic Investigation ◽  
Cubic Structure ◽  
Average Size

In present work, we synthesized monodisperse Fe3O4microsphere using a free-surfactant solvothermal reduction route and investigated effect of the precursor concentration (FeCl3∙6H2O and NaAc) on microsphere sizes under other reaction conditions held constant. The morphologies, structures, and magnetism of the products were characterized by SEM, XRD, FTIR and VSM. The results showed that the Fe3O4 microsphere with a tunable average size range from 120 nm to 300 nm is composed of many Fe3O4collective nanoparticles. Their average diameters increased with increase of precursor FeCl3∙6H2O concentration but decreased with increase of precursor NaAc concentration. The X-ray diffraction (XRD) pattern confirmed that the Fe3O4microspheres belong to cubic structure. Magnetic investigation reveals that the Fe3O4microspheres have higher saturation magnetization and negligible coercivity at room temperature.

scholarly journals Magnetic Properties of Well-Aligned ZnO Nanorod Arrays Grown by a Simple Hydrothermal Reaction

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jiangni Yun ◽  
Rui Qu ◽  
Zhiyong Zhang ◽  
Jun Li
Keyword(s):  
Room Temperature ◽  
Hydrothermal Reaction ◽  
Substrate Surface ◽  
Room Temperature Ferromagnetism ◽  
Zno Nanorods ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays ◽  
X Ray Diffraction ◽  
Half Metallic

Well-aligned ZnO nanorod arrays with room temperature ferromagnetism were prepared on glass substrate through hydrothermal method. The as-prepared nanorod arrays were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), photoluminescence (PL) spectrum, and magnetization measurements. The XRD and SEM results indicated that the ZnO nanorods are with the wurtzite structure and exhibit preferential (002) orientation withc-axis perpendicular to the substrate surface. The PL results suggested that the possible defect in the as-prepared ZnO nanorod arrays might beVZn,Oi, orOZn. The first-principles calculations reveal that the room temperature ferromagnetism may result from theVZndefects present in the ZnO nanorod and the hybridization of the Zn 3d states with O 2p states is responsible for the half-metallic ferromagnetism in ZnO nanorod.

Sign in / Sign up

Export Citation Format

Share Document