Magnetically recyclable silica-coated magnetite-molybdate nanocatalyst and its applications in N-formylation reactions under solvent-free conditions-

2022 ◽  
Vol 19 ◽  
Author(s):  
Runjhun Tandon ◽  
Shripad Patil ◽  
Nitin Tandon ◽  
Pushpendra Kumar
Keyword(s):  
Catalytic Activity ◽  
Solvent Free ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Co Precipitation ◽  
Coated Nanoparticle ◽  
Scanning Electron

Abstract: A novel magnetite silica-coated nanoparticle-supported molybdate nanocatalyst has been prepared successfully by a simple co-precipitation method. Prepared nanocatalyst has been characterized by different techniques like Fourier Transmission Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDX). Further, the catalytic activity of the nanocatalyst was explored for N-formylation reactions under solvent-free conditions. Interestingly, the catalyst could be reused for 10 cycles and only 2 mol % of the catalyst was sufficient to catalyze the N-formylation reaction at 700C under solvent-free conditions.

Synthesis of Magnetic Modified Organobentonite as Adsorbent for Degradation of Orange II

2013 ◽  
Vol 838-841 ◽  
pp. 2306-2309
Author(s):  
Guang Hua Wang ◽  
Kun Chen ◽  
Wen Bing Li ◽  
Dong Wan ◽  
Qin Hu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Reaction Medium ◽  
Precipitation Method ◽  
Basal Spacing ◽  
Orange Ii ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Co Precipitation ◽  
Scanning Electron

Magnetic modified organobentonite (Fe3O4/CTAB–Bent) was synthesized by chemical co-precipitation method in which CTAB–Bent was firstly achieved via ion–exchange.The composite materials have been characterized by powder X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and Scanning electron microscopy (SEM) . The results revealed that basal spacing of bentonite was increased through organic modification and the Fe3O4 particles synthesized which covering the surfaces of bentonite .Compared with natural bentonite, the adsorption capacity of Fe3O4/CTAB–Bent for Orange II was greatly enhanced and can be easily separated from the reaction medium by an external magnetic field after the treatment.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

scholarly journals A Novel Strong Cyan Luminescence Emission of Tb2O3 Particles

2021 ◽  
Author(s):  
Fatma Unal
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ammonium Carbonate ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Terbium Oxide ◽  
X Ray ◽  
Ft Ir ◽  
Pl Emission ◽  
Scanning Electron

Abstract Terbium oxide (Tb2O3) particles (NPs) were synthesized by precipitation method using ammonium carbonate as precipitation agent. Effects of precursor molarity (0.1, 0.15 and 0.2 M) on photoluminescence (PL) behaviour of the NPs were investigated. The presence of the Tb2O3 phase was confirmed by X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses. Morphological investigations of the produced powders were made by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). It showed that the morphology of Tb2O3 particles transformed from the nanograin chain to bundles morphology of rod-like as the amount of precursor molarity increased. Emission spectrum were investigated by Photoluminescence (PL) Spectroscopy. All the Tb2O3 particles exhibited the strongest peak at 493 nm ascribed to 5D4-7F6 (magnetic dipole (MD), C2) transition. The increase in the number of C2 sites released from the MD transition with the increase of the precursor molarity caused a negative increase in the b* (yellowness/blueness of the emission) value in the CIE diagram, indicating that the colour shifted to the blue region. The Tb2O3 particles produced by the precipitation method exhibited novel strong cyan colour and the PL emission intensity increased with increasing molarity.

Copper (II) Removal by Using Manganese Ferrite in PVA-Alginate Beads

2015 ◽  
Vol 735 ◽  
pp. 177-181
Author(s):  
Ee Ting Wong ◽  
Pei Cheng Teh ◽  
Kian Hwa Chan ◽  
Ani Idris
Keyword(s):  
Sodium Hydroxide Solution ◽  
Alginate Beads ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drinking Water Standard ◽  
Ft Ir ◽  
Co Precipitation ◽  
Control Study ◽  
Alginate Matrix

The magnetic nanoparticles of manganese-doped magnetite (Mn-Fe2O4) were synthesized by the simple co-precipitation method. The stable Mn2+ and Fe3+ salts in the ratio of 1:2 in aqueous solution, were added into the sodium hydroxide solution to form the Mn-Fe2O4 precipitate at temperature of 95°C. The synthesized nanoparticles were then characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) and X-ray diffraction spectroscopy (XRD). It was then entrapped in the PVA-alginate matrix to form the nanophotoadsorbent in beads form. The synthesized nanoparticles embedded bead was characterized by Scanning Electron Microscopy (SEM). The effects of various parameters, such as contact time, pH, nanoparticles dosage were investigated. The control study was also performed to reveal the performance of photo-adsorbent towards the Cu (II) removal under the light and dark conditions. It was found that the removal efficiency of the Cu (II) achieved 97.07% (1.46ppm) which complied to the WHO drinking water standard of less than 1.5ppm after 180 min treatment.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

Synthesis and Characterization of Structure of Fe3O4@Graphene Oxide Nanocomposites

2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu
Keyword(s):  
Graphene Oxide ◽  
Drug Carrier ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Co Precipitation ◽  
Ft Ir Spectroscopy

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.

Effects of Aging and Temperature on the Oriental Growth of Hydroxyapatite

2011 ◽  
Vol 308-310 ◽  
pp. 2180-2186
Author(s):  
Hui Yang ◽  
Fei Fei Huang ◽  
Ke Wei Xu
Keyword(s):  
Sem Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Directional Growth ◽  
X Ray ◽  
Preparation Conditions ◽  
A Value ◽  
Co Precipitation ◽  
Effects Of Aging ◽  
Scanning Electron

In order to find a simple way to prepare oriental HA, only by controlling the preparation conditions, a co-precipitation method was used to prepare an oriented HA. The influences of temperature and aging on its directional growth were investigated kinetically and thermodynamically. The chemical composition was characterized by X-Ray diffraction and Fourier transform infrared. The morphologies were observed by scanning electron microscopy (SEM). The oriented parameters of HA (c/a) were calculated by Scherrer equation. The results show that the temperature rise in the process of synthesis, aging or calcining inhibited the growth of HA crystal in the direction of c-axis. Aging for 24 h benefited the growth along c-axis, whereas aging for 36 h was in favor of the decreasing of the c/a value. The supernatant-replacement during aging exerted the same effect on the growth with the rising of temperature. The SEM analysis result shows that the morphology of the produced HA particles looked like a uniform needle shape and had a good dispersion.

Concentration-Dominated Temperature-Dependence of Upconversion Luminescence in Gd6WO12 Nanophosphor Co-Doped with Er3+ and Yb3+

2016 ◽  
Vol 16 (4) ◽  
pp. 3534-3541
Author(s):  
Yanqiu Zhang ◽  
Baojiu Chen ◽  
Xiangping Li ◽  
Jiashi Sun ◽  
Jinsu Zhang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Thermal Quenching ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Microscopic Morphology ◽  
Co Precipitation ◽  
Co Doped ◽  
Scanning Electron

Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the Er3+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.

Study on Preparation of LiNi0.5Co0.2Mn0.3O2 Precursor-Spherical Ni0.5Co0.2Mn0.3O2(OH)2

2015 ◽  
Vol 816 ◽  
pp. 676-681 ◽  
Author(s):  
Xiao Long Qu ◽  
Zheng Fu Zhang ◽  
Jin Cheng ◽  
Xiao Yan Wang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tap Density ◽  
Homogeneous Particle ◽  
Co Precipitation ◽  
Scanning Electron

The spherical Ni0.5Co0.2Mn0.3(OH)2 powders were prepared by ammonia-hydroxide co-precipitation method. The influence of different synthesizing factors on the precursors characteristic were investigated. The product prepared with optimized condition has tap density of D≥1.7g·cm-3, and middle particle size D50≈3.6μm. The X-ray diffraction (XRD) results showed that the precursor can be indexed by a hexagonal β-Ni (OH)2 structure. The scanning electron microscope (SEM) results showed that the powders had quasi-spherical pattern and homogeneous particle size distribution.

scholarly journals Method for preventing air pollution: Methane oxidation by two types of catalysts

2014 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Cristina Ileana Covaliu ◽  
Gina Alina Traistaru ◽  
Gigel Paraschiv
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Air Pollution ◽  
Methane Oxidation ◽  
Sol Gel ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Scanning Electron

Abstract Methane oxidation using different catalysts is an useful process for preventing air pollution. This study presents the methane oxidation by two types of catalysts: Pd-Sn/Al2O3 and spinel mixed oxide, CuFe2O4. The Pd-Sn/Al2O3 was successfully prepared by sol-gel method and CuFe2O4 by co-precipitation method. The catalysts obtained have been characterized structurally, morphologically and texturally by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). The catalytic activity tests regarding methane oxidation were also performed.

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