Influences of synthesis conditions on preparation and characterization of Ti-MWW zeolite membrane by secondary hydrothermal synthesis

2020 ◽  
Vol 297 ◽  
pp. 110004
Author(s):  
Jiamin Jiang ◽  
Meihua Zhu ◽  
Yongsheng Liu ◽  
Yuqin Li ◽  
Tian Gui ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Zeolite Membrane ◽  
Synthesis Conditions ◽  
Mww Zeolite

Synthesis and characterization of the lead borate Pb6B12O21(OH)6

2016 ◽  
Vol 71 (8) ◽  
pp. 925-933 ◽  
Author(s):  
Sandra Schönegger ◽  
Teresa S. Ortner ◽  
Klaus Wurst ◽  
Gunter Heymann ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Potassium Nitrate ◽  
Lattice Parameters ◽  
Synthesis And Characterization ◽  
Lead Borate ◽  
Hydrothermal Conditions ◽  
Organic Reagents ◽  
Synthesis Conditions

AbstractA lead borate with the composition Pb6B12O21(OH)6 was synthesized through a hydrothermal synthesis, using lead metaborate in combination with sodium nitrate and potassium nitrate. The compound crystallizes in the trigonal, non-centrosymmetric space group P32 (no. 145) with the lattice parameters a = 1176.0(4), c = 1333.0(4) pm, and V = 0.1596(2) nm3. Interestingly, the data of Pb6B12O21(OH)6 correct the structure of a literature known lead borate with the composition “Pb6B11O18(OH)9”. For the latter compound, nearly identical lattice parameters of a = 1176.91(7) and c = 1333.62(12) pm were reported, possessing a crystal structure, in which the localization and refinement of one boron atom was obviously overlooked. The structure of Pb6B12O21(OH)6 is built up from trigonal planar BO3 and tetrahedral BO4 groups forming complex chains. The Pb2+ cations are located between neighboring polyborate chains. The here reported compound Pb6B12O21(OH)6 and “Pb6B11O18(OH)9” were, however, produced under different synthesis conditions. While “Pb6B11O18(OH)9” was synthesized via a hydrothermal synthesis including ethylenediamine and acetic acid, the here reported lead borate Pb6B12O21(OH)6 could be obtained under moderate hydrothermal conditions (240°C) without the addition of organic reagents.

Hydrothermal Synthesis and Characterization of Vanadium Oxide Nanotubes

2006 ◽  
Vol 11-12 ◽  
pp. 535-538 ◽  
Author(s):  
Jia Wei ◽  
Jing Chang Zhang
Keyword(s):  
Hydrothermal Synthesis ◽  
Vanadium Oxide ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Hydrothermal Conditions ◽  
Oxide Layers ◽  
Synthesis Conditions ◽  
Vanadium Oxide Nanotubes

Vanadium oxide nanotubes (VOX-NT) have been synthesized by using amine as structure-directing template and V2O5 as precursor under hydrothermal conditions (160°C, 7 days). The XRD, FTIR and TEM have been performed to optimize the synthesis conditions such as the amine species and the molar ratio between V2O5 and amine. The results of TEM show that the same molar ratio of V2O5 and butylamine (1.0:1.0) produce a mass of nanotubes which have intact figuration. The diameters are about 80nm for most of the nanotubes prepared by V2O5 and octadecylamine. While the obtained VOX-NT prepared by V2O5 and n-butylamine were found having diameters from 28.51nm to 97.80nm and the distance between the vanadium oxide layers is 1.84 nm comfirmed by XRD. FTIR also display that some changes of the structure have been occurred during the formation of the nanotubes compared with the staring materials.

Hydrothermal Synthesis and Characterization of Cu-Saponite

2013 ◽  
Vol 669 ◽  
pp. 124-130 ◽  
Author(s):  
Xian Mei Xie ◽  
Lian Duan ◽  
Xing Yu Cui ◽  
Jian Ming Zhang ◽  
Jie Xing
Keyword(s):  
Hydrothermal Synthesis ◽  
Raw Materials ◽  
Copper Nitrate ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
Synthesis Conditions ◽  
Ft Ir ◽  
Adsorption Desorption

Hydrothermal synthesis of Cu-saponite was achieved using copper nitrate and sodium silicate as the raw materials. The mixtures of starting materials were treated under hydrothermal conditions at 60–230°C for 6–48h. The effect of different synthetic parameters such as hydrothermal temperature and hydrothermal time on the structure development of Cu-saponite was discussed. All the samples were characterized by X-ray diffraction (XRD), FT-IR, scanning electron microscopy (SEM) and nitrogen physisorption techniques. The results of the study showed that the obtained Cu-saponite exhibited better crystallinity at 200°C for 36h. Both increasing hydrothermal temperature and the duration of hydrothermal treatment yielded better crystallized Cu-saponite as determined by XRD. SEM micrographs revealed plate-like shape of the synthetic Cu-saponite. The results of nitrogen physisorption measurements showed different synthesis conditions resulted in different adsorption-desorption isotherms.

Hydrothermal Synthesis and Characterization of SnS2Nanocrystals

2001 ◽  
Vol 30 (12) ◽  
pp. 1294-1295 ◽  
Author(s):  
Chunrui Wang ◽  
Kaibin Tang ◽  
Qing Yang ◽  
Yitai Qian ◽  
Cunyi Xu
Keyword(s):  
Hydrothermal Synthesis ◽  
Synthesis And Characterization

Understanding of Lithium Insertion into λ-MnO2 Compounds

1998 ◽  
Vol 548 ◽  
Author(s):  
S. Sarciaux ◽  
A. Le Gal La Salle ◽  
A. Verbaere ◽  
Y Piffard ◽  
D. Guyomard
Keyword(s):  
Oxygen Content ◽  
Structural Parameters ◽  
Reversible Capacity ◽  
Rechargeable Batteries ◽  
Structural Water ◽  
Synthesis Conditions ◽  
Starting Compound ◽  
Physico Chemical ◽  
New Compounds

ABSTRACTA large variety of EMD and HTMD samples with various oxygen and water contents and various structural parameters Pr and Mt has been prepared. We show that the physico-chemical and structural parameters of the λ-MnO2 compounds are related to the synthesis conditions. New compounds were obtained with unusual amounts of intergrowth and twinning defects.The Li insertion study focuses on a comprehensive investigation of the relationships between the material characteristics of the samples and their Li insertion behavior, and on the structural characterization of selected compounds after cycling. The oxygen content drastically affects the shape of the discharge curve after the first cycle and the total reversible capacity. The amount of structural water has an influence on the transformation kinetics of the starting phase. For optimized oxygen content (y= 2 in MnOY), the intrinsic reversible Li insertion capacity is maximum when the amount of microtwinning defects is minimum and when the structure is either mostly Ramsdellite or faulted Pyrolusite. Results show that, upon cycling, the λ-MnO2 structure seems to evoluate towards less Pyrolusite defects together with the apparition of new kinds of defects.This work shows that λ-MnO2, compounds could be good candidates for the cathode application of Li-metal rechargeable batteries, provided that the physico-chemical and structural parameters of the starting compound are well chosen.

Hydrothermal Synthesis and Structural Characterization of Four Scandium Phosphate Frameworks

2003 ◽  
Vol 15 (20) ◽  
pp. 3818-3825 ◽  
Author(s):  
Ivor Bull ◽  
Victor Young ◽  
Simon J. Teat ◽  
Luming Peng ◽  
Clare P. Grey ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Structural Characterization
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