Carbonyl oxygen-coordinated metallic cobalt nanoparticles anchored on hybrid mesoporous silica matrix to enhance 4-nitrophenol hydrogenation

Metallic cobalt nanoparticles are successfully obtained by the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The pyrolysates of CoC2O4. 2H2O were investigated by TG-DSC and SEM. The results showed that there are two stages in the process of the pyrolytic decomposition of CoC2O4. 2H2O in the argon gas. The crystal water in CoC2O4. 2H2O was lost from 150 °C to 275 °C. CoC2O4was pyrolysized into metallic cobalt powder from 300 °C to 500 °C. At the same time, the pattern of pyolysate of CoC2O4. 2H2O was fined at 347.7 °C for 10 min. But, the particles of pyolysate of CoC2O4. 2H2O were sintered into cobalt blocks at 500.0 °C for 10 min. Therefore, the conditions of pyrolytic decomposition of CoC2O4. 2H2O were controlled if single cobalt powder was obtained at 500.0 °C..

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A surface modification scheme for incorporation of nanocrystals in mesoporous silica matrix

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2005.06.040 ◽

2005 ◽

Vol 178 (10) ◽

pp. 2980-2986 ◽

Cited By ~ 9

Author(s):

Lan Zhao ◽

Guangshan Zhu ◽

Daliang Zhang ◽

Yue Chen ◽

Shilun Qiu

Keyword(s):

Surface Modification ◽

Mesoporous Silica ◽

Silica Matrix

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The Use of Mesoporous Systems for Preparation of One-Dimensional Ordered Magnetic Nanowires

MRS Proceedings ◽

10.1557/proc-788-l6.1 ◽

2003 ◽

Vol 788 ◽

Cited By ~ 1

Author(s):

Andrei A. Eliseev ◽

Kirill S. Napolskii ◽

Dmitry F. Gorozhankin ◽

Alexei V. Lukashin ◽

Yuri D. Tretyakov ◽

...

Keyword(s):

Mesoporous Silica ◽

Data Storage ◽

Magnetic Measurements ◽

Decomposition Temperature ◽

Silica Matrix ◽

Information Storage ◽

Molar Ratio ◽

Magnetic Nanowires ◽

One Dimensional ◽

Novel Variant

ABSTRACTHere we report the synthesis and investigation of iron and iron oxide nanowire arrays using mesoporous silica as a host material. In the present work a novel variant of synthesis of ordered magnetic nanowires in the mesoporous silica matrix was suggested. The method is based on the incorporation of a hydrophobic metal compound into the hydrophobic part of silica-surfactant composite. The amount of iron intercalated into the mesoporous matrix was measured by chemical analysis. In all samples it corresponds well to with the molar ratio SiO2: Fe = 9:1. To provide crystallinity of nanowires additional thermal treatment was performed. Thus prepared nanocomposites were characterized by TEM, ED, SAXS, SANS, BET and magnetic measurements. The anisotropy parameters of nanowires were determined using two non-correlated methods: temperature dependence of magnetic susceptibility and small angle polarized neutron scattering. It was found that the particle length increases with the increasing of the decomposition temperature of the metal complex. Obviously it deals with crystallization and growth of metal particles inside the pores at a constant diameter of a single particle. For iron containing sample annealed at 375 °C (form factor of nanowire is about 40), the coercive force at room temperature was found to be 145 Oe at saturation magnetization of 1.2 emu/g, which is not far from modern information storage. It was shown that particles shape and size are in good agreement with that of the pores. Particles are uniform and well ordered in the silica matrix. Thus, the suggested method leads to one-dimensional anisotropic nanostructures which could find an application as high-density data storage magnetic media.

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High peroxidase-like activity of metallic cobalt nanoparticles encapsulated in metal–organic frameworks derived carbon for biosensing

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2017.09.013 ◽

2018 ◽

Vol 255 ◽

pp. 2050-2057 ◽

Cited By ~ 31

Author(s):

Wenfei Dong ◽

Yunxia Zhuang ◽

Siqi Li ◽

Xiaodan Zhang ◽

Hongxiang Chai ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Cobalt Nanoparticles ◽

Metallic Cobalt ◽

Metal Organic

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Synthesis of highly dispersed ultra-small cobalt nanoparticles within the cage-type mesopores of 3D cubic mesoporous silica via double agent reduction method for catalytic hydrogen generation

Applied Surface Science ◽

10.1016/j.apsusc.2018.11.171 ◽

2019 ◽

Vol 470 ◽

pp. 764-772 ◽

Cited By ~ 6

Author(s):

Mu-Hsin Lee ◽

Juti Rani Deka ◽

Chun-Jiun Cheng ◽

Ning-Fang Lu ◽

Diganta Saikia ◽

...

Keyword(s):

Mesoporous Silica ◽

Reduction Method ◽

Hydrogen Generation ◽

Cobalt Nanoparticles ◽

Highly Dispersed ◽

Catalytic Hydrogen ◽

Double Agent ◽

Cubic Mesoporous

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Distinct Methodologies to Produce Capped Mesoporous Silica with Hydroxyapatite and the Influence in Intracellular Signaling as Cytotoxicity on Human Umbilical Vein Endothelial Cells

Bioengineering ◽

10.3390/bioengineering8090125 ◽

2021 ◽

Vol 8 (9) ◽

pp. 125

Author(s):

Aline Oliveira da Silva de Barros ◽

Luciana Magalhães Rebêlo Alencar ◽

Frank Alexis ◽

Ralph Santos-Oliveira

Keyword(s):

Mesoporous Silica ◽

Intracellular Signaling ◽

Biomedical Applications ◽

Fiber Type ◽

Umbilical Vein ◽

Silica Matrix ◽

In Vitro Assays ◽

Material Structure ◽

Step Method ◽

One Step

Mesoporous silica has unique properties such as controllable mesoporous structure and size, good biocompatibility, high specific surface area, and large pore volume. For that reason, this material has been broadly functionalized for biomedical applications, such as optical imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), ultrasound imaging, and widely employed as drug delivery systems. In this study, we synthesized fiber-type mesoporous silica capped with hydroxyapatite (ordered SiO2–CaO–P2O5 mesoporous silica). Its biological activity was evaluated through a cellular and molecular approach using HUVEC cell culture. Two distinct methodologies have produced the ordered SiO2–CaO–P2O5 mesoporous silica: (i) two-step Ca-doped silica matrix followed by hydroxyapatite crystallization inside the Ca-doped silica matrix and (ii) one-step Ca-doped silica matrix formed with the hydroxyapatite crystallization. Further analysis included: elemental analysis, transmission, scanning electron microscopy images, Small and Wide-Angle X-ray Diffraction analysis, Fourier Transform Infrared, and in vitro assays with HUVEC (cytotoxicity and immunoblotting). The hydroxyapatite capping methodology significantly affected the original mesoporous material structure. Furthermore, no cellular or molecular effect has been observed. The promising results presented here suggest that the one-step method to obtain hydroxyapatite capped mesoporous silica was effective, also demonstrating that this material has potential in biomedical applications.

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