scholarly journals An Ultrasonic Accelerated Three-Component Condensation By KCC-1: A High Mechanical Stability Silica Nanospheres As A Good Catalyst For Ultrasonic Irradiation

2021 ◽  
Author(s):  
Hourieh Sadat Oboudatian ◽  
Javad Safaei-Ghomi
Keyword(s):  
Electron Microscopy ◽  
Ultrasonic Irradiation ◽  
Mechanical Stability ◽  
High Surface ◽  
High Surface Area ◽  
Silica Sphere ◽  
Nano Silica ◽  
Efficient Catalyst ◽  
Ft Ir ◽  
High Mechanical Stability

Abstract Fibrous nano-silica sphere (KCC-1) has appeared as a good and efficient catalyst for ultrasonic irradiation conditions in chemical reactions. This catalyst has the unique properties such as a fibrous surface morphology, high surface area and high mechanical stability. The results indicated that the KCC-1 nanocatalyst could be used as high-performance catalysts under high temperature and pressure condition in organic reaction under ultrasonic irradiation. Morphology, structure, and composition of the fibrous nano-silica sphere were described by N2 adsorption–desorption analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR). In this work, we used KCC-1@NH2 nanosilica as a basic catalyst for the preparation of chromenes under ultrasonic irradiation conditions for the first time. The recyclability, nontoxicity and high stability of the catalyst, combined with low reaction times and excellent yields, make the present protocol very useful for the synthesis of the title products under ultrasonic conditions. The produced products were confirmed via 1H NMR, 13C NMR, FT-IR analysis.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Photocatalytic Degradation of Allura Red by MN-Ni Co-Doped Nanotitania under Visible Light Irradiation

2019 ◽  
Vol 8 (12) ◽  
pp. 650-657
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
X Ray ◽  
Allura Red ◽  
Co Doping ◽  
Ft Ir ◽  
Co Doped

Photocatalyst has been extensive interest because of it’s new innovation to the reduce the contamination in the environment. A straight forward and economical procedure has been employed by sol-gel technique for the co-doping of Mn2+ and Ni2+ into TiO2 . The co-doped and undoped photocatalysts were described by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV-Visible Diffused Reflectance Spectroscopy (UV Vis-DRS), Transmission electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET). The portrayal results shows that anatase and rutile mixed phase was observed for some co-doped nanocatalysts and the remaining catalysts exhibits anatase phase only. It was observed by FT-IR that the shifting of frequency of Ti-O-Ti in the catalysts was seen due to substitutional doping of Mn and Ni by replace Ti and O, further the photocatalysts shows rough morphology, irregular shape of particle with size (6.5nm) and having high surface area (135.70 m2/g), less band energy (2.7 eV). The photocatalytic action of these materials was assessed by the degradation of Allura red (AR) as a contaminant. The results shows that AR has degraded within 60 minutes at doping concentrations 0.25 Wt% of Mn2+ion and 1.0 Wt% of Ni2+ ion in TiO2 (NMT2) at an optimum reaction parameters pH-4, catalyst dose 0.070g/L and at AR initial dye concentration 0.010g/L.

scholarly journals Guanidinylated SBA-15/Fe3O4 mesoporous nanocomposite as an efficient catalyst for the synthesis of pyranopyrazole derivatives

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fereshte Hassanzadeh-Afruzi ◽  
Somayeh Asgharnasl ◽  
Sara Mehraeen ◽  
Zeinab Amiri-Khamakani ◽  
Ali Maleki
Keyword(s):  
Catalytic Activity ◽  
High Surface ◽  
High Surface Area ◽  
Lewis Acid Site ◽  
Efficient Catalyst ◽  
Physicochemical Features ◽  
Ft Ir ◽  
Post Synthesis

AbstractIn this study, a novel mesoporous nanocomposite was fabricated in several steps. In this regard, SBA-15 was prepared by the hydrothermal method, next it was magnetized by in-situ preparation of Fe3O4 MNPs. After that, the as-prepared SBA-15/Fe3O4 functionalized with 3-minopropyltriethoxysilane (APTES) via post-synthesis approach. Then, the guanidinylated SBA-15/Fe3O4 was obtained by nucleophilic addition of APTES@SBA-15/Fe3O4 to cyanimide. The prepared nanocomposite exhibited excellent catalytic activity in the synthesis of dihydropyrano[2,3-c]pyrazole derivatives which can be related to its physicochemical features such as strong basic sites (presented in guanidine group), Lewis acid site (presented in Fe3O4), high porous structure, and high surface area. The characterization of the prepared mesoporous nanocomposite was well accomplished by different techniques such as FT-IR, EDX, FESEM, TEM, VSM, TGA, XRD and BET. Furthermore, the magnetic catalyst was reused at least six consequent runs without considerable reduction in its catalytic activity.

Facile Synthesis of Cu2O nanoparticle-loaded Carbon Nanotubes Composite Catalysts for Reduction of 4-Nitrophenol

2020 ◽  
Vol 16 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Yao Feng ◽  
Ran Wang ◽  
Juanjuan Yin ◽  
Fangke Zhan ◽  
Kaiyue Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mechanical Stability ◽  
Catalytic Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Reduction Reaction ◽  
Cycle Performance ◽  
Simple Method ◽  
Composite Catalysts ◽  
Cu2o Nanoparticles

Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and.has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP. Methods: CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized water. Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious. Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.

Synthesis of Indole Derivatives Using Biosynthesized ZnO-CaO Nanoparticles as an Efficient Catalyst

2021 ◽  
Vol 66 ◽  
pp. 61-71
Author(s):  
Tahereh Heidarzadeh ◽  
Navabeh Nami ◽  
Daryoush Zareyee
Keyword(s):  
Electron Microscopy ◽  
Indole Derivatives ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
X Ray ◽  
Transmission Electron ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Eggshell Waste ◽  
Aromatic And Aliphatic Amines

The principal aim of this research is using biosynthesized ZnO-CaO nanoparticles (NPs) for preparation of indole derivatives. ZnO-CaO NPs have been prepared using Zn(CH3COO)2 and eggshell waste powder in solvent-free conditions. Morphology and structure of NPs were determined by FT-IR, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive spectra (EDS). It was used as a highly efficient catalyst for the synthesis of indole derivatives. Some indole derivatives were synthesized by the reaction of indole, formaldehyde, aromatic and aliphatic amines in the presence of ZnO-CaO NPs (5 mol%) in ethanol under reflux conditions. The assigned structure was further established by CHN analyses, NMR, and FT-IR spectra. Because of excellent capacity, the exceedingly simple workup and good yield, eco-friendly catalyst ZnO-CaO NPs were proved to be a good catalyst for this reaction.

scholarly journals Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
Titanium Silicate ◽  
Ft Ir ◽  
Synthesized Materials ◽  
Visible Light Photocatalytic

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

Large-scale and facile synthesis of a porous high-entropy alloy CrMnFeCoNi as an efficient catalyst

2020 ◽  
Vol 8 (35) ◽  
pp. 18318-18326 ◽  
Author(s):  
Hailong Peng ◽  
Yangcenzi Xie ◽  
Zicheng Xie ◽  
Yunfeng Wu ◽  
Wenkun Zhu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
High Entropy Alloy ◽  
Facile Synthesis ◽  
Efficient Catalyst ◽  
High Entropy

Porous high entropy alloy CrMnFeCoNi exhibited remarkable catalytic activity and stability toward p-nitrophenol hydrogenation. The enhanced catalytic performance not only resulted from the high surface area, but also from exposed high-index facets with terraces.

Magnetic Fe3O4@C nanoparticles as adsorbents for removal of amoxicillin from aqueous solution

2013 ◽  
Vol 69 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Babak Kakavandi ◽  
Ali Esrafili ◽  
Anoushiravan Mohseni-Bandpi ◽  
Ahmad Jonidi Jafari ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Kinetic Models ◽  
High Surface ◽  
High Surface Area ◽  
Order Kinetic ◽  
Magnetic Composites ◽  
Factors Affecting ◽  
Transmission Electron ◽  
Pseudo Second Order

In the present study, powder activated carbon (PAC) combined with Fe3O4 magnetite nanoparticles (MNPs) were used for the preparation of magnetic composites (MNPs-PAC), which was used as an adsorbent for amoxicillin (AMX) removal. The properties of magnetic activated carbon were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunaeur, Emmett and Teller and vibrating sample magnetometer. The operational factors affecting adsorption such as pH, contact time, adsorbent dosage, initial AMX concentration and temperature were studied in detail. The high surface area and saturation magnetization for the synthesized adsorbent were found to be 671.2 m2/g and 6.94 emu/g, respectively. The equilibrium time of the adsorption process was 90 min. Studies of adsorption equilibrium and kinetic models revealed that the adsorption of AMX onto MNPs-PAC followed Freundlich and Langmuir isotherms and pseudo-second-order kinetic models. The calculated values of the thermodynamic parameters, such as ΔG°, ΔH° and ΔS° demonstrated that the AMX adsorption was endothermic and spontaneous in nature. It could be concluded that MNPs-PAC have a great potential for antibiotic removal from aquatic media.

scholarly journals Synthesis and characterization of porous silica and polyaniline-porous silica composite materials with high surface area

2014 ◽  
Vol 49 (1) ◽  
pp. 1-8
Author(s):  
US Akhtar ◽  
MK Hossain ◽  
MS Miran ◽  
MYA Mollah
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Nitrogen Adsorption ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Cylindrical Pore

Porous silica materials were synthesized from tetraethyl orthosilicate (TEOS) using Pluronic P123 (non-ionic triblock copolymer, EO20PO70O20) as template under acidic conditions which was then used to prepare polyaniline (PAni) and porous silica composites (PAnisilica) at a fixed molar ratio. These materials were characterized by nitrogen adsorption-desorption isotherm measured by Barrett-Joyner- Halenda (BJH) method and pore size distribution from desorption branch and surface area measured by the Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), TEM-energy dispersive X-ray (EDX) and Fourier transform infrared (FT-IR) spectroscopy. The composite maintains its structure even after the polymerization and the polymer is dispersed on the inorganic matrix. The rod-like porous silica was about 1?m to 1.5 ?m long and on an average the diameter was in the range of 300- 500 nm. The SEM and TEM images show well ordered 2d hexagonal pore, high specific surface area (850 m2g-1) and uniform pore size of ca. 6.5 nm in diameter. After incorporation of PAni inside the silica pore, framework of porous silica did not collapse and the surface area of the composite was as high as 434 m2g-1 which was 5.5 time higher than our previous report of 78.3 m2g-1. Due to shrinkage of the framework during the incorporation of aniline inside the silica, the pore diameter slightly increase to 7.5 nm but still showing Type IV isotherm and typical hysteresis loop H1 implying a uniform cylindrical pore geometry. DOI: http://dx.doi.org/10.3329/bjsir.v49i1.18847 Bangladesh J. Sci. Ind. Res. 49(1), 1-8, 2014

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