Effect of Temperature and KOH Concentration on Hydrothermal Synthesis of SrTiO3 Dendrites

2012 ◽  
Vol 430-432 ◽  
pp. 225-228
Author(s):  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Qi Qun Zou ◽  
Yong Gang Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Effect Of Temperature ◽  
Morphology Evolution

SrTiO3dendrites were successfully synthesized by hydrothermal method. An obvious morphology evolution from cubic-like shape to dendrite was observed when KOH concentration varied from 1M to 0.1M at 80°C. A decrease in KOH concentration was found to be favorable for the formation of dendrites. Star-like shape SrTiO3crystals instead of dendrites were obtained when the temperature was lowed to 40°C.

Low Temperature Synthesis of PbTiO3 Nanoparticles

2005 ◽  
Vol 475-479 ◽  
pp. 3517-3520
Author(s):  
Yu Jing Sun ◽  
Shi Tian ◽  
Xiao Bing Li
Keyword(s):  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Tetragonal Phase ◽  
Lead Acetate ◽  
Average Diameter ◽  
Effect Of Temperature ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis

PbTiO3 nano-sized powders were synthesized at 150oC by a new hydrothermal [denoted as sol-hydrothermal] method by using modified titanium tetra-n-butoxide and lead acetate as the precursors. Furthermore, tetragonal PbTi0.8O2.6 nano-sized powders were obtained by this method at 80oC. Compared with hydrothermal synthesis, the effect of temperature on the formation of products prepared by sol-hydrothermal was investigated. The characteristics of products were studied by XRD, TEM and SAXS. The results show sol-hydrothermal method choosing acetylacetonate-modified titanium tetra-n-butoxide and lead acetate to form a sol could obtain PbTiO3 in 120nm size and PbTi0.8O2.6 powders with average diameter of 30nm, and both of them are pure tetragonal phase. In addition, PbTi0.8O2.6 could be converted into PbTiO3 gradually after annealed at giving condition.

The effect of temperature on morphology and electrochemical properties of NiCo2S4 by hydrothermal synthesis

2018 ◽  
Vol 11 (03) ◽  
pp. 1850063
Author(s):  
Yanwei Sui ◽  
Haihua Hu ◽  
Yuanming Zhang ◽  
Bin Tang ◽  
Jiqiu Qi ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Current Density ◽  
Level Structure ◽  
Hydrothermal Process ◽  
Effect Of Temperature ◽  
Second Step ◽  
Carbon Sphere

The hydrothermal method, using the template is a conspicuous way to change the morphology of the product, so it is used widely in many reports. The effect of temperature on morphology of NiCo2S4 by hydrothermal synthesis and its electrochemical properties is distinct as high-performance electrode materials for supercapacitors. With the help of the template (carbon sphere), different morphologies of NiCo2S4 under 90[Formula: see text]C, 120[Formula: see text]C and 180[Formula: see text]C were obtained. They have different properties after electrochemical analysis. In order to build a hierarchical multi-level structure, two-step vulcanization was carried out at each temperature, resulting in the difference in the morphology and performance of the six sample of electrodes. The obtained NiCo2S4 electrodes exhibit 1000[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text] in the second-step of the hydrothermal process under 120[Formula: see text]C, which is superior to the microblocks NiCo2S4 electrode (90[Formula: see text]C, 888[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]) and microparticles NiCo2S4 electrode (180[Formula: see text]C, 574[Formula: see text]F[Formula: see text]g[Formula: see text] at the same current density) in the second-step hydrothermal, which shows a high-rate capability (640[Formula: see text]F[Formula: see text]g[Formula: see text] at 20[Formula: see text]A[Formula: see text]g[Formula: see text]). The obtained nanoparticles NiCo2S4 under 180[Formula: see text]C in the first-step hydrothermal electrode had an excellent cycle retention rate (89.7%), although its specific capacitance was lower. At the same time, the specific capacitance of these sample electrodes obtained in the second-step hydrothermal process is superior to those from the first-step. It was mainly attributed to the fact that temperature can influence the morphology by controlling ion exchange. And our experiment aims to use the hydrothermal method and the template method to find a more suitable temperature range to provide more ideas.

Morphology evolution, energy transfer and multicolor luminescence of lanthanide-doped Ba2LaF7 nanocrystals via a one-step hydrothermal synthesis

CrystEngComm ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 564-572 ◽  
Author(s):  
Yini Mao ◽  
Li Jiang ◽  
Rui Ye ◽  
Jun Yang ◽  
Shanshan Hu
Keyword(s):  
Energy Transfer ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Morphology Evolution ◽  
One Step

Lanthanide-doped Ba2LaF7 nanocrystals were successfully synthesized via a one-step hydrothermal method.

Study of the temperature effect on the morphology and structure of ZnS nanoparticles synthesized by hydrothermal method

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3379-3388
Author(s):  
Claudia J. Bahena-Martínez ◽  
Nayely Torres-Gómez ◽  
Alfredo R. Vilchis-Néstor
Keyword(s):  
Hydrothermal Synthesis ◽  
Temperature Effect ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Zinc Sulphide ◽  
Effect Of Temperature ◽  
Zns Nanoparticles ◽  
Temperature Increment ◽  
Morphology And Structure ◽  
Subsequent Decomposition

AbstractThe control over the materials structure is crucial for the modulation of its properties, in order to achieve this control is important to know the formation mechanism of the material as function of parameters used. For this purpose, the effect of temperature (120, 140, 160 and 180 °C) on the hydrothermal synthesis of zinc sulphide is evaluated and a proposal of the sequence of reactions formation of zinc sulphur is presented. ZnS nanostructures with blend-phase were obtained, the temperature increment induces the growth of the nanostructure ranged between .62 and 12.72 nm, furthermore, increase the crystallinity of the ZnS nanostructures. The proposed reactions suggest the formation of a complex of thioacetamide with the Zn+2 and its subsequent decomposition into ZnS.

P-type conducting transparent characteristics of delafossite Ca doped CuScO2 prepared by hydrothermal synthesis

2021 ◽  
Author(s):  
Han Gao ◽  
Xianwei Zeng ◽  
Qiang Guo ◽  
Zhi Yang ◽  
Yanwen Deng ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Delafossite Oxides ◽  
P Type

Ca doped CuScO2 (CSO) delafossite oxides with 3-4 μm were synthesized through hydrothermal method using Cu(NO3)2•3H2O, Sc(NO3)3•xH2O as precursor at 240 °C for 24 h in this work. The influence...

scholarly journals Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1040 ◽  
Author(s):  
Getachew Solomon ◽  
Raffaello Mazzaro ◽  
Vittorio Morandi ◽  
Isabella Concina ◽  
Alberto Vomiero
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Crystal Morphology ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Mos2 Nanosheets ◽  
Microwave Assisted

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.

Rapid microwave assisted hydrothermal synthesis of porous α-Fe2O3 nanostructures as stable and high capacity negative electrode for lithium and sodium ion batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (44) ◽  
pp. 34761-34768 ◽  
Author(s):  
B. Nageswara Rao ◽  
P. Ramesh Kumar ◽  
O. Padmaraj ◽  
M. Venkateswarlu ◽  
N. Satyanarayana
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
High Capacity ◽  
Negative Electrode ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Base Catalyst ◽  
Microwave Assisted

Porous α-Fe2O3 nanostructures were developed in the presence of a base catalyst by a rapid microwave assisted hydrothermal method.

Morphology Evolution and Luminescence Properties of YF3: Sm Nano-/Microcrystals

2012 ◽  
Vol 463-464 ◽  
pp. 112-118
Author(s):  
Feng Tao ◽  
Geng Zhu ◽  
Zhi Jun Wang ◽  
Feng Pan ◽  
Yu Feng Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Growth Mechanism ◽  
Room Temperature ◽  
Red Light ◽  
Environmentally Friendly ◽  
Morphology Evolution ◽  
Flat Panel Display ◽  
Flat Panel ◽  
Display Devices ◽  
Potential Applications

Abstract. Recently, there has been increasting interest in the doping of nano-/microcrystal hosts with Sm3+. However, very few examples of Sm3+doped YF3-based nanophosphors have been reported. In this paper, a variety of uniform YF3:Sm nano-/microcrystals have been successfully prepared by a facile, effective, and environmentally friendly hydrothermal method. The morphology evolution process has been investigated by quenching the reaction at different time. Based on the results, a possible growth mechanism is presented in detail. The as-obtained YF3:Sm nano-/microcrystals show strong yellow and red light emissions under room temperature, which is quite different from those reported previously and might find potential applications in fields such as light phosphor powers and advanced flat panel display devices.

Hydrothermal Synthesis of Bi1.5ZnNb1.5O7 Nanopowders

2007 ◽  
Vol 561-565 ◽  
pp. 495-498 ◽  
Author(s):  
Jin Liang Huang ◽  
Xiao Wang ◽  
Liu Shuan Yang ◽  
Chun Wei Cui ◽  
Xing Hua Yang
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Pyrochlore Phase ◽  
Synthesis Temperature ◽  
Minimum Size ◽  
Hydrothermal Reactions ◽  
Prolonged Reaction Time ◽  
Scherrer Equation ◽  
Xrd Patterns

The cubic pyrochlore phase Bi1.5ZnNb1.5O7 nanopowder was successfully synthesized by the hydrothermal method (HTM) from the starting materials: Bi(NO3)3·5H2O, ZnO, Nb2O5 and the mineralizer: KOH. The XRD patterns prove that the cubic pyrochlore phase Bi1.5ZnNb1.5O7 nanopowder can be obtained by HTM, and TEM photographs show that the powders present the regularly granular shape, when the hydrothermal reactions were conducted at synthesis temperatures 140~220°C and reaction time for 6~48h. The crystalline sizes of the powders were calculated by the Scherrer equation to be about 43~49nm. The crystalline sizes decreased both with the increase in synthesis temperature and the prolonged reaction time until they reached to the minimum size about 43nm at 220°C for 24h.However, they tended to increase when the reaction time was above 24h.

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