scholarly journals Synthesis of ZSM-23 Zeolite by Two-Stage Temperature-Varied Crystallization and Its Isomerization Performance

2020 ◽  
Vol 10 (21) ◽  
pp. 7546
Author(s):  
Xiaoyan Chen ◽  
Hongjuan Xi ◽  
Congbiao Chen ◽  
Zhongyi Ma ◽  
Bo Hou
Keyword(s):  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aluminum Sulfate ◽  
The Body ◽  
Aluminum Nitrate ◽  
Two Stage ◽  
Long Chain

Several ZSM-23 zeolites with different acid distributions are synthesized by two-stage temperature-varied crystallization and changing the species of aluminum source via conventional hydrothermal synthesis. The crystallinity, micropores, external specific surface area and the Si/Al ratios are measured by XRD, BET, ICP and XPS, indicating that both the body phase and the surface of the zeolite synthesized by two-stage temperature-varied crystallization have higher Si/Al ratio, and the zeolite synthesized with aluminum nitrate as the aluminum source exhibit the largest specific surface area. The properties of acidity and Pt obtained by NH3-TPD, TEM, Py-IR and H2-TPR show that the suitable B-acid distribution leads to high Pt dispersion over the zeolite. Applying these catalysts to the isomerization of n-dodecane, the zeolite synthesized with aluminum sulfate as aluminum source by two-step temperature-varied crystallization shows the best isomerization performance, that the selectivity of i-dodecane reaches 81.2% at 90.7% conversion. Therefore, the matching of acidity, external specific surface area and Pt dispersion of the zeolites is the key to improve the isomerization performance of long-chain alkanes.

Design of ZnMoO4 porous nanosheet with oxygen vacancy as better performance electrode material for supercapacitor

2021 ◽  
Author(s):  
Pengxi Li ◽  
Jiepeng Wang ◽  
Liming Li ◽  
Shili Song ◽  
Xianming Yuan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Oxygen Vacancy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrode Material ◽  
Reduction Method

ZnMoO4 with oxygen vacancy (ZnMoO4-OV) porous nanosheet was synthesized by hydrothermal synthesis and hydrogenation reduction method. The ZnMoO4-OV porous nan sheet delivers a higher specific surface area together with a...

Preparation of Nanosize Anatase TiO2 Powders by Hydrothermal Synthesis

2007 ◽  
Vol 336-338 ◽  
pp. 2017-2020 ◽  
Author(s):  
Fan Yong Ran ◽  
Wen Bin Cao ◽  
Yan Hong Li ◽  
Xiao Ning Zhang
Keyword(s):  
Grain Size ◽  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Reaction Temperature ◽  
Reaction System ◽  
Anatase Tio2 ◽  
Holding Time ◽  
Precursor Concentration

Nanosize anatase TiO2 powders have been synthesized by hydrothermal synthesis by using technical grade TiOSO4 as precursor and urea as precipitating agent. The initial pressure of the reaction system was set at 6 MPa. Stirring speed was fixed at 300r/min. The reaction system reacted at the temperature ranged from 110 to 150°C for holding 2hrs to 8hrs and the concentration of the precursor was ranged from 0.25M to1.5M. XRD patterns show that the synthesized powders are in the form of anatase phase. Calculated grain size is ranged from 6.7 to 8.9nm by Scherrer method from the line broadening of the (101) diffraction peak of anatase. The specific surface area of the powders synthesized under different conditions is ranged from 124 to 240m2/g. The grain size of the powders increases with the increase of the reaction temperature, holding time and precursor concentration, respectively. The specific surface area decreases with the increase of reaction temperature and holding time, and does not obviously change with the change of precursor concentration when the concentration of the precursor is less than 1M. However, when the concentration is higher than 1M, the specific surface area will decrease quickly with the increase of the precursor concentration. XRD and DSC-TG analysis shows that the synthesized anatase TiO2 will begin to transform to rutile TiO2 at about 840°C. When heated to 1000°C for holding 1h, the anatase powders will transform to rutile completely.

A Simple Hydrothermal Synthesis of Cadmium Sulfide Wrapped on Graphene Nanocomposite for Supercapacitor Applications

2021 ◽  
Vol 21 (12) ◽  
pp. 5835-5845
Author(s):  
Ranjith Balu ◽  
Arivuoli Dakshanamoorthy
Keyword(s):  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Cadmium Sulfide ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Current Density ◽  
Specific Capacity ◽  
Cds Nanoparticles ◽  
Electrochemical Characteristics

Supercapacitor with high specific capacity is desirable for various energy storage and high powerdensity applications. Though Graphene has been the preferred material for high current density, nanocomposites have been attempted to increase the specific capacitance. Hydrothermal synthesis of cadmium sulfide/graphene (CdS/G) nanocomposite with CdS nanoparticles anchored/decorated over the graphene sheets is reported. The structural studies reveal the hexagonal phase of the prepared materials. The specific surface area (BET) and porosity is found to increase upon nanocomposite formation. The electrochemical characteristics such as cyclic voltammetry (CV), GCD and EIS of the CdS/G nanocomposite have been investigated. The capacitance of CdS/G nanocomposite almost doubled to 248 Fg−1 indicating the enhanced performance of the nanocomposite system and in addition it also showed excellent cycling stability of 74.8 percent after 1000 cycles. The supercapacitor investigated retained the initial energy density after charge-discharge, at 0.5 A/g for 1000 cycles. The graphene nanosheets increased the specific surface area and interfacial electron transfer of the composite material. It enhances the specific capacitance and cyclic stability of the supercapacitor device.

scholarly journals Smart Calcium Phosphate Bioceramic Scaffold for Bone Tissue Engineering

2012 ◽  
Vol 529-530 ◽  
pp. 19-23 ◽  
Author(s):  
G. Daculsi ◽  
Thomas Miramond ◽  
Pascal Borget ◽  
Serge Baroth
Keyword(s):  
Tissue Engineering ◽  
Stem Cell ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mechanical Test ◽  
The Body ◽  
Stable Phase ◽  
X Rays ◽  
Cell Colonization

The development of CaP ceramics involved a better control of the process of resorption and bone substitution. Micro Macroporous Biphasic CaP, (MBCP+) is a concept based on an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases Ca and P ions into the biological medium. The MBCP+ is selected for tissue engineering in a large European research program on osteoinduction and mesenchymal stem cell technology (REBORNE 7thEU frame work program, Regenerative Bone defects using New biomedical Engineering approaches,www.reborne.org). We have optimized the matrices in terms of their physical, chemical, and crystal properties, to improve cell colonization and to increase kinetic bone ingrowth. The fast cell colonization and resorption of the material are associated to the interconnected macropores structure which enhances the resorption bone substitution process. The micropore content involves biological fluid diffusion and suitable adsorption surfaces for circulating growth factors. The bioceramics developed for this project was fully characterized using X-Ray diffraction, FTIR, X-rays micro tomography, Hg porosimetry, BET specific surface area, compressive mechanical test, and SEM. Preclinical tests on the optimized scaffold were realized in critical size defects in several sites of implantation and animals (rats, rabbits, goats, dogs).The smart scaffold has a total porosity of 73%, constituted of macropores (>100µm), mesopores of 10 to 100µm and high micropores (<10µm) content of more or less 40%. The crystal size is <0.5 to 1 µm and the specific surface area was around 6m2/g. Thein vivoexperiment indicated higher colonization by osteogenic cells demonstrating suitable matrices for tissue engineering. The HA/TCP ratio of 20/80 was also more efficient for combination with total bone marrow or stem cell cultivation and expansion before to be implanted.

The Hydrothermal Synthesis and Photocatalysis of TiO2 Powders

2011 ◽  
Vol 183-185 ◽  
pp. 2024-2027
Author(s):  
Li Ming Jiang
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Organic Molecule ◽  
Photocatalytic Performance ◽  
Hydrothermal Conditions ◽  
Anatase Structure

Titania powders were prepared under hydrothermal conditions by employing organic molecule β-cyclodextrin(CD) as template, and characterized by means of TGA、XRD、BET . The effects of the pH on the specific surface area and photocatalytic performance of titania were discussed. The results showed that titania powders were anatase structure;the titania powders with specific surface area up to 216.2 m2g-1 were prepared while the system pH was about 1 , and the powders had the best photocatalytic activity.

Hydrothermal synthesis of Sm-doped Bi2WO6 flower-like microspheres for photocatalytic degradation of rhodamine B

CrystEngComm ◽  
2019 ◽  
Vol 21 (41) ◽  
pp. 6208-6218 ◽  
Author(s):  
Xianghui Zhang ◽  
Mingming Zhang ◽  
Kaixuan Cao
Keyword(s):  
Hydrothermal Synthesis ◽  
Optical Absorption ◽  
Specific Surface ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rhodamine B

Sm-doped Bi2WO6 with 3D flower-like microspheres structure shows extremely high photodegradation activity and superior stability and reusability because of the optimum optical absorption activity and the larger specific surface area.

scholarly journals Hydrothermal Synthesis of 1T-MoS2/Pelagic Clay Composite and Its Application in the Catalytic Reduction of 4-Nitrophenol

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7020
Author(s):  
Nan Li ◽  
Qiwei Sun ◽  
Peiping Zhang ◽  
Shubo Jing
Keyword(s):  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Fine Particles ◽  
Catalytic Reduction ◽  
Large Specific Surface Area ◽  
Mos2 Nanosheets ◽  
Pelagic Clay

Pelagic clay is an emerging marine resource with strong hydrophilicity, fine particles and a large specific surface area. In this work, a 1T-MoS2/pelagic clay composite was fabricated by hydrothermal synthesis. In the composite, 1T-MoS2 nanosheets are evenly dispersed on the surface of the clay minerals, significantly reducing the agglomeration of MoS2. Compared with pure 1T-MoS2, the 1T-MoS2 nanosheets generated on the surface of pelagic clay have significantly smaller lateral dimensions and thicknesses. Moreover, the specific surface area is much larger than that of the pure 1T-MoS2 nanosheets fabricated by the same method, indicating that the active sites of the MoS2 sheets are fully exposed. In addition, the composite exhibited excellent hydrophilicity, leading to a high dispersibility in aqueous solutions. In this work, the composite was used as a catalyst in the reduction of 4-nitrophenol (4-NP), and the conversion of 4-NP reached up to 96.7%. This result shows that the 1T-MoS2/pelagic clay composite is a promising catalyst in a variety of reactions.

Hydrothermal Synthesis of Phthalocyanine Sensitization TiO2 Nanowires

2012 ◽  
Vol 531 ◽  
pp. 387-390 ◽  
Author(s):  
Ling Ling Zhan ◽  
Hai Feng Chen ◽  
Jian Qiang Ye
Keyword(s):  
Heat Treatment ◽  
Hydrothermal Synthesis ◽  
Methyl Orange ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Raw Materials ◽  
Nano Tio2 ◽  
Prepared Sample ◽  
Photocatalytic Activities

Phthalocyanine sensitization nano-TiO2 have been successfully synthesized by controlling TiO2's nuclear growth and CoPcTs adsorption simultaneously via a hydrothermal way by using TiO2, NaOH and CoPcTs as raw materials. XRD, BET, TG-DTA and FI-IR were used to characterize the features of the as-synthesized phthalocyanine sensitization TiO2 nanowires. The results showed that anatase nano- TiO2 with phthalocyanine sensitization have been prepared after heat treatment and cyanine materials are easily decomposed when the temperature above 450 °C; the specific surface area TiO2 and phthalocyanine sensitization nano-TiO2 is 42.2 m2/g and 110.5 m2/g, respectively. Methyl orange dyes were chosen to test the photocatalytic activities of the as-prepared sample in this experiment, and it found that the loading of 1% wt CoPcTs was the best.

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