scholarly journals The Growth of Bismuth Sulfide Nanorods from Spherical-Shaped Amorphous Precursor Particles under Hydrothermal Condition

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Pravas Kumar Panigrahi ◽  
Amita Pathak
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Room Temperature ◽  
Hydrothermal Process ◽  
Reaction System ◽  
Oriented Attachment ◽  
Complexing Agent ◽  
Sulfur Source ◽  
Bismuth Sulfide ◽  
Morphological Studies

A surfactant/solid-template-free hydrothermal process has been developed for the synthesis of single-crystalline nanorods of bismuth sulfide (Bi2S3) using triethanolamine as a complexing agent for the Bi3+ ions and elemental sulfur, solubilized in monoethanolamine, as the sulfur source. X-ray diffraction and morphological studies of a series of samples synthesized at different reaction conditions suggest that the growth of nanorods occurred at the expense of the low-crystalline spherical precursor particles of aminium compounds of bismuth sulfide or bismuth sulfate formed at room temperature. In the process, the reaction condition is optimized for obtaining crystalline nanorods of pure Bi2S3 with high aspect ratio. From the XRD, XPS, and HRTEM analysis of the samples, the growth of nanorods was assessed to be due to the cooperative effects of solid-solution-solid transformation and controlled oriented attachment. The hydrothermal process parameters and the presence of water in the reaction system have been found to play a crucial role in the formation of high aspect ratio nanorods. The optical band gap of the synthesized sample at optimized conditions is found to be 1.46 eV as calculated from its diffused reflectance spectrum at room temperature.

scholarly journals Fe(II)-phthalocyanine supported on chitosan aerogel as a catalyst for oxidation of alcohols and alkyl arenes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Azimi ◽  
Ahmad Poursattar Marjani ◽  
Sajjad Keshipour
Keyword(s):  
Aspect Ratio ◽  
Heterogeneous Catalyst ◽  
High Aspect Ratio ◽  
Room Temperature ◽  
Oxidation Reactions ◽  
Mild Conditions ◽  
Oxidation Of Alcohols ◽  
Aromatic Alcohols ◽  
Aldehydes And Ketones ◽  
Low Toxicity

AbstractManipulation of materials is considered as one of the eminent strategies to create desirable catalysts. In this regard, increasing surface area and decreasing dimensions of catalysts have been widely employed on account of effectiveness of these methods. Herein, aerogel form of chitosan as a sustainable, and high aspect ratio compound is employed as a green support for the catalytic purposes. Chitosan aerogel was modified with Fe(II)-phthalocyanine to produce a heterogeneous catalyst for oxidation reactions. The synthesized catalyst promoted the oxidation reactions of alcohols and alkyl arenes to the corresponding aldehydes and ketones using H2O2 as an oxidant in 24 h. The reactions for aliphatic and aromatic alcohols gave turnover numbers of 106–109 at 80 °C and 106–117 at room temperature, respectively. The oxidations of alkyl arenes were carried out with turnover numbers laying in the range of 106–117 at 100 °C. The low toxicity, inexpensive nature, and recycling possibility of the catalyst accompanied by the reaction mild conditions, clean oxidant, and excellent yields offer chitosan aerogel modified with Fe(II)-phthalocyanine as a promising catalyst for oxidation reactions.

Synthesis of high aspect ratio CuO submicron rods through oriented attachment and their application in lithium-ion batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (62) ◽  
pp. 49968-49972 ◽  
Author(s):  
Hequan Wang ◽  
Yunpeng Zong ◽  
Wenxia Zhao ◽  
Li Sun ◽  
Ling Xin ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Lithium Ion Batteries ◽  
High Aspect Ratio ◽  
Lithium Ion ◽  
Building Blocks ◽  
Oriented Attachment

High aspect ratio CuO submicron rods were synthesized via the polymer-assisted oriented attachment of nanocrystal building blocks along with calcination.

scholarly journals High-Aspect Ratio β-Ga2O3 Nanorods via Hydrothermal Synthesis

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 594 ◽  
Author(s):  
Hyun Bae ◽  
Tae Yoo ◽  
Youngbin Yoon ◽  
In Lee ◽  
Jong Kim ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Oriented Attachment ◽  
Calcination Process ◽  
Type Semiconductor ◽  
Subsequent Calcination ◽  
Effect Transistor ◽  
Attachment Mechanism ◽  
Transfer Properties

High-aspect ratio β-Ga2O3 nanorods consisting of prism-like crystals were formed using gallium oxyhydroxide and ammonia hydroxide via a hydrothermal synthesis followed by the subsequent calcination process. The formation of high-aspect ratio β-Ga2O3 nanorods was attributed to the oriented attachment mechanism that was present during the hydrothermal synthesis. A field-effect transistor was fabricated using the high-aspect ratio β-Ga2O3 nanorod, and it exhibited the typical charge transfer properties of an n-type semiconductor. This facile approach to forming high-aspect ratio nanorods without any surfactants or additives can broaden the science of β-Ga2O3 and expedite the integration of one-dimensional β-Ga2O3 into future electronics, sensors, and optoelectronics.

scholarly journals Solventless Conducting Paste Based on Graphene Nanoplatelets for Printing of Flexible, Standalone Routes in Room Temperature

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 829 ◽  
Author(s):  
Andrzej Pepłowski ◽  
Piotr Walter ◽  
Daniel Janczak ◽  
Żaneta Górecka ◽  
Wojciech Święszkowski ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Percolation Threshold ◽  
Sheet Resistance ◽  
High Aspect Ratio ◽  
Room Temperature ◽  
Graphene Nanoplatelets ◽  
Wearable Electronics ◽  
Bending Tests ◽  
Flexible Applications

Novel printable composites based on high aspect ratio graphene nanoplatelets (GNPs), fabricated without using solvents, and at room temperature, that can be employed for flexible, standalone conducting lines for wearable electronics are presented. The percolation threshold of examined composites was determined to be as low as 0.147 vol% content of GNPs. Obtained sheet resistance values were as low as 6.1 Ω/sq. Stretching and bending tests are presented, proving suitability of the composite for flexible applications as the composite retains its conductivity even after 180° folding and 13.5% elongation.

One-pot synthesis of high aspect ratio titanium dioxide nanorods using oxalic acid as a complexing agent

2016 ◽  
Vol 163 ◽  
pp. 39-42 ◽  
Author(s):  
Zachary Zander ◽  
Raymond Yagloski ◽  
Jared DeCoste ◽  
Dajie Zhang ◽  
Brendan G. DeLacy
Keyword(s):  
Titanium Dioxide ◽  
Aspect Ratio ◽  
Oxalic Acid ◽  
High Aspect Ratio ◽  
Complexing Agent ◽  
One Pot ◽  
One Pot Synthesis ◽  
Titanium Dioxide Nanorods

Complexing agent assisted synthesis of high aspect ratio Fe3+/Mg2+ layered double hydroxides

2011 ◽  
Vol 54 (3-4) ◽  
pp. 281-286 ◽  
Author(s):  
Michael R. Schütz ◽  
Andreas E. Schedl ◽  
Friedrich E. Wagner ◽  
Josef Breu
Keyword(s):  
Aspect Ratio ◽  
Layered Double Hydroxides ◽  
High Aspect Ratio ◽  
Complexing Agent ◽  
Double Hydroxides

High Aspect Ratio Microstructures in LiNbO3 Produced by Ion Beam Enhanced Etching

2005 ◽  
Vol 908 ◽  
Author(s):  
Frank Schrempel ◽  
Thomas Gischkat ◽  
Holger Hartung ◽  
Ernst Bernhard Kley ◽  
Werner Wesch ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Room Temperature ◽  
Ion Beam ◽  
Perfect Crystal ◽  
Target Atom ◽  
Irradiation Temperature ◽  
Temperature Irradiation ◽  
Different Temperatures ◽  
Etching Behavior

AbstractThis work presents data on damage evolution, volume expansion and etching behavior of LiNbO3 irradiated with Ar+-ions as a function of irradiation and etching conditions. Single crystals of x- and z-cut LiNbO3 were irradiated at room temperature and 15 K using Ar-ions with energies between 60 and 600 keV and ion fluences between 5 × 1012 and 1 × 1015 cm-2. The damage formation investigated with RBS channeling analysis depends on the crystal cut as well as on the irradiation temperature. Irradiation of z-cut material at 300 K causes complete amorphization at 0.4 dpa (displacements per target atom). In contrast 0.27 dpa are sufficient to amorphize the x-cut LiNbO3. Irradiation at 15 K reduces the number of displacements per atom necessary for amorphization to 0.18 dpa. To study the etching behavior ∼500 nm thick amorphous layers were generated via multiple irradiations with Ar+-ions. Etching was performed in HF-solution of different concentration and at different temperatures. The influence of the irradiation and etching conditions on damage formation and etching of LiNbO3 is discussed. In conclusion, negligible etching of the perfect crystal, high etching rates and high contrast of Ion Beam Enhanced Etching (IBEE) allow the realization of high aspect ratio microstructures in LiNbO3.

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