Preparation of Functionalized Superparamagnetic Fe3O4@Dopamine@Metal Ions (Cu+,Ru2+) Nanocomposites and its Catalytic Applications

In this work, we present a simple method for the synthesis of metal ions stabilized on dopamine modified iron oxide nanoparticles (Fe3O4@DA@Mx+) and their catalytic applications in important organic transformation reactions. Two different metal ions (Cu+1 and Ru2+) are studied in this work. It is observed that both synthesized Fe3O4@DA@Cu+ and Fe3O4@DA@Ru2+ can effortlessly be separated from the reaction medium by positioning an external magnetic field. Dopamine, which is used as an anchor between Fe3O4 and metal ions, increases the solubility of catalyst in reaction medium and prevents leaching of metal ions from the catalyst surface. Here Fe3O4@DA@Cu+ is used in the synthesis of 1,2,3-triazole derivatives via azide-alkyne cycloaddition reactions and Fe3O4@DA@Ru2+ is used for transfer hydrogenation reaction of various aryl ketones. The Fe3O4@DA@Mx+ nanocomposite is characterized via powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA) and vibrating-sample magnetometer (VSM). The Fe3O4@DA@Mx+ catalytic systems can be reused in the reaction mixture up to five times without significant loss in their catalytic activity.

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Preparation of Functionalized Superparamagnetic Fe3O4@Dopamine@Metal Ions (Cu+,Ru2+) Nanocomposites and its Catalytic Applications

10.26434/chemrxiv.12993401 ◽

2020 ◽

Author(s):

Renuka Singh ◽

Shukla Majhi ◽

Keshav Sharma ◽

Mohd. Ali ◽

Chandra Shekhar Pati Tripathi ◽

...

Keyword(s):

Electron Microscopy ◽

Metal Ions ◽

Photoelectron Spectroscopy ◽

Reaction Medium ◽

Significant Loss ◽

Transfer Hydrogenation ◽

Simple Method ◽

Catalytic Systems ◽

X Ray ◽

Catalytic Applications

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Recyclable Heterogeneous Fe-Mo Nanocatalyst: Application in Solvent Free Synthesis of β-enaminones

Current Organocatalysis ◽

10.2174/2213337206666190415125053 ◽

2019 ◽

Vol 6 (3) ◽

pp. 238-247

Author(s):

Swapnil R. Bankar

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Significant Loss ◽

Solvent Free ◽

Catalyst Loading ◽

Spectroscopic Techniques ◽

Impregnation Method ◽

Molybdenum Catalyst ◽

X Ray ◽

Solvent Free Condition

Background: In recent years, green organic transformation has become a challenge for a chemist in areas like social sector, health, and environment. Literature survey revealed that a nano magnetite supported heterogeneous catalysis is an emergent field with huge application in chemical synthesis. Objective: In the present article, the aim was to develop a simple and facile method to carry organic reaction under benign media. So, the focus was on the synthesis of nano-magnetite supported molybdenum catalyst and its application in β-enaminones synthesis. Methods: Magnetically recyclable heterogeneous ferrite-molybdenum catalyst was prepared by simple impregnation method. The synthesized nanocatalyst Fe-Mo was well analysed by spectroscopic techniques like X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission gun scanning electron microscopy and vibrating-sample magnetometry. The functionalized nanocatalyst Fe-Mo was employed in the synthesis of β-enaminones under solvent free condition. Results: The competency of synthesized nanocatalyst-Fe-Mo was observed to be good for the synthesis of β-enaminones derivatives under microwave irradiation and gave excellent yield (86-96%) of the product. The catalyst was recycled for more than five consecutive runs without significant loss in its activity. Conclusion: In the present research article, synthesis of highly active, magnetically recyclable Fe- Mo nanocatalyst was obtained from easily available precursor. The MNP was stable under investigated conditions and effective in β-enaminones synthesis. The simple eco-friendly method, low catalyst loading, short transformation time, and reusability of the catalyst thoroughly follow the sustainable protocol.

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Biosynthesized Highly Stable Au/C Nanodots: Ideal Probes for the Selective and Sensitive Detection of Hg2+ Ions

Nanomaterials ◽

10.3390/nano9020245 ◽

2019 ◽

Vol 9 (2) ◽

pp. 245 ◽

Cited By ~ 4

Author(s):

Sada Venkateswarlu ◽

Saravanan Govindaraju ◽

Roopkumar Sangubotla ◽

Jongsung Kim ◽

Min-Ho Lee ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Metal Ions ◽

Fluorescent Probe ◽

Photoelectron Spectroscopy ◽

Industrial Development ◽

Carbon Nanodots ◽

Detection Mechanism ◽

X Ray ◽

Transmission Electron

The enormous ongoing industrial development has caused serious water pollution which has become a major crisis, particularly in developing countries. Among the various water pollutants, non-biodegradable heavy metal ions are the most prevalent. Thus, trace-level detection of these metal ions using a simple technique is essential. To address this issue, we have developed a fluorescent probe of Au/C nanodots (GCNDs-gold carbon nanodots) using an eco-friendly method based on an extract from waste onion leaves (Allium cepa-red onions). The leaves are rich in many flavonoids, playing a vital role in the formation of GCNDs. Transmission electron microscopy (TEM) and Scanning transmission electron microscopy-Energy-dispersive X-ray spectroscopy (STEM-EDS) elemental mapping clearly indicated that the newly synthesized materials are approximately 2 nm in size. The resulting GCNDs exhibited a strong orange fluorescence with excitation at 380 nm and emission at 610 nm. The GCNDs were applied as a fluorescent probe for the detection of Hg2+ ions. They can detect ultra-trace concentrations of Hg2+ with a detection limit of 1.3 nM. The X-ray photoelectron spectroscopy results facilitated the identification of a clear detection mechanism. We also used the new probe on a real river water sample. The newly developed sensor is highly stable with a strong fluorescent property and can be used for various applications such as in catalysis and biomedicine.

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Synergistically homogeneous-heterogeneous Fenton catalysis of trace copper ion and g-C3N4 for degradation of organic pollutants

Water Science & Technology ◽

10.2166/wst.2021.296 ◽

2021 ◽

Author(s):

Z. Y. Yao ◽

G. X. Zhu ◽

T. L. Lu ◽

Y. Z. Zhan

Keyword(s):

Electron Microscopy ◽

Catalytic Activity ◽

Metal Ions ◽

Photoelectron Spectroscopy ◽

Organic Pollutant ◽

Copper Ion ◽

Heterogeneous Fenton ◽

Paramagnetic Resonance ◽

X Ray ◽

Synergistic Catalysis

Abstract Using the bulk g-C3N4 as a precursor, four g-C3N4 nanosheets were further prepared by ultrasonic, thermal, acid, and alkali exfoliation. The structures of these materials were characterized by various techniques such as X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-Ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The synergistical Fenton catalysis of these materials with Cu2+ was evaluated by using rhodamine B as a simulated organic pollutant. The results showed that there existed a significant synergistical Fenton catalysis between Cu2+ and g-C3N4. This synergistic effect can be observed even when the concentration of Cu2+ was as low as 0.064 mg L−1. The properties of g-C3N4 strongly influenced the catalytic activity of the Cu2+/g-C3N4 system. The coexistent of Cu2+ and the alkali exfoliated g-C3N4 showed the most excellent catalytic activity. Hydroxyl radicals as oxidizing species were confirmed in the Cu2+/g-C3N4 system by electron paramagnetic resonance spectrum. The synergistic catalysis may be attributed to the easier reduction of Cu2+ adsorbed on the g-C3N4. This study provided an excellent Fenton catalytic system, and partly solved the rapid deactivation of heterogeneous Fenton catalysts caused by the leaching of metal ions. HIGHTLIGHTS There exists a significant synergistical Fenton catalysis between trace Cu2+ and g-C3N4. The Cu2+ concentration is lower than the maximum acceptable limit in drinking water. This study partly solved the rapid deactivation caused by the leaching of metal ions. This study reminds researchers to pay attention to the possible synergistic catalysis between leached ions and supports.

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Magnetic and Structural Properties of Nanocomposite ZnO-Fe3O4 Films Prepared by Solid-State Synthesis

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.215.158 ◽

2014 ◽

Vol 215 ◽

pp. 158-162

Author(s):

Liudmila E. Bykova ◽

V.G. Myagkov ◽

I.A. Tambasov ◽

O.A. Bayukov ◽

Victor S. Zhigalov ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Solid State ◽

Photoelectron Spectroscopy ◽

Magnetic Measurements ◽

X Ray Diffraction ◽

Simple Method ◽

Physical Methods ◽

X Ray ◽

Scanning Electron

A simple method for obtaining ZnO-Fe3O4 nanocomposites using solid-state reaction Zn + 3Fe2O3 ZnO + 2Fe3O4 is suggested. An analysis of the characteristics and properties of ZnO-Fe3O4 nanocomposites was carried out by a combination of structural and physical methods (X-ray diffraction, scanning electron microscopy, photoelectron spectroscopy, Mössbauer measurements, X-ray fluorescent analysis, and magnetic measurements). The magnetization of the hybrid ZnO-Fe3O4 films is equal to 440 emu/cm3. The resulting Fe3O4 nanoparticles are surrounded by a ZnO shell and have sizes ranging between 20 and 40 nm.

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Facet-Dependent Reactivity of Fe2O3/CeO2 Nanocomposites: Effect of Ceria Morphology on CO Oxidation

Catalysts ◽

10.3390/catal9040371 ◽

2019 ◽

Vol 9 (4) ◽

pp. 371 ◽

Cited By ~ 16

Author(s):

Maria Lykaki ◽

Sofia Stefa ◽

Sόnia Carabineiro ◽

Pavlos Pandis ◽

Vassilis Stathopoulos ◽

...

Keyword(s):

Electron Microscopy ◽

Co Oxidation ◽

Photoelectron Spectroscopy ◽

Rational Design ◽

Mixed Oxides ◽

Specific Activity ◽

Catalytic Performance ◽

Catalytic Systems ◽

X Ray ◽

Full Characterization

Ceria has been widely studied either as catalyst itself or support of various active phases in many catalytic reactions, due to its unique redox and surface properties in conjunction to its lower cost, compared to noble metal-based catalytic systems. The rational design of catalytic materials, through appropriate tailoring of the particles’ shape and size, in order to acquire highly efficient nanocatalysts, is of major significance. Iron is considered to be one of the cheapest transition metals while its interaction with ceria support and their shape-dependent catalytic activity has not been fully investigated. In this work, we report on ceria nanostructures morphological effects (cubes, polyhedra, rods) on the textural, structural, surface, redox properties and, consequently, on the CO oxidation performance of the iron-ceria mixed oxides (Fe2O3/CeO2). A full characterization study involving N2 adsorption at –196 °C, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) was performed. The results clearly revealed the key role of support morphology on the physicochemical properties and the catalytic behavior of the iron-ceria binary system, with the rod-shaped sample exhibiting the highest catalytic performance, both in terms of conversion and specific activity, due to its improved reducibility and oxygen mobility, along with its abundance in Fe2+ species.

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A simple method to prepare carbon nanotubes from sunflower seed hulls and sago and their application in supercapacitor

Pigment & Resin Technology ◽

10.1108/prt-10-2013-0090 ◽

2015 ◽

Vol 44 (1) ◽

pp. 7-12 ◽

Cited By ~ 3

Author(s):

H.Y. Zhang ◽

H.J. Niu ◽

Y.M. Wang ◽

C. Wang ◽

X.D. Bai, ◽

...

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Photoelectron Spectroscopy ◽

Sunflower Seed ◽

Electrochemical Impedance ◽

Cyclic Voltammograms ◽

Production Scale ◽

Simple Method ◽

Content Type ◽

X Ray

Purpose – The purpose of this paper was to provide a simple method for the preparation of carbon nanotubes (CNTs) by pyrolysing sunflower seed hulls and sago and to evaluate the application of such CNTs in supercapacitors. Design/methodology/approach – The CNTs were obtained by pyrolysing sunflower seed hulls and sago at 800°C. The prepared CNTs were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammograms, galvanostatic charge and discharge and electrochemical impedance spectra methods. Findings – The CNTs had large surface areas as determined by the methylene blue method and the Brunauer – Emmett – Teller method. And the CNTs that were prepared by pyrolysing the natural sunflower seed hulls (denoted as CNTs-1) and sago (denoted as CNTs-2) had capacitances of 86.9 F/g and 26.7 F/g, respectively. Research limitations/implications – The capacitances of CNTs can be further improved. Practical implications – The exceptional electronic and mechanical properties of CNTs prepared lend the CNTs to diverse applications including electrocatalysts, hydrogen storage, photovoltaic devices actuators, energy storage, field-emitting flat panel displays and composites. Originality/value – Currently, CNTs have not yet been used in the industry at a mass production scale due to high costs associated. The outcomes of the study reported in this article could provide a convenient method in aid of industrialisation of the production of CNTs.

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LignoPhot: Photoactive Hybrid lignin/Bi4O5Br2/BiOBr Composite for Complex Pollutants Removal

10.26434/chemrxiv.13554677 ◽

2021 ◽

Author(s):

Tetyana Budnyak ◽

Joy Onwumere ◽

Ievgen V. Pylypchuk ◽

Aleksander Jaworski ◽

Jianhong Chen ◽

...

Keyword(s):

Electron Microscopy ◽

Metal Ions ◽

Photoelectron Spectroscopy ◽

Organic Dyes ◽

Dye Degradation ◽

Low Cost ◽

Resonance Spectroscopy ◽

Hydrolysis Lignin ◽

X Ray ◽

Main Component

Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We report on photoactive lignin/Bi4O5Br2/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by Bi4O5Br2/BiOBr nanosheet photocatalysts. The structure of the hybrid material was investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy including energy dispersive X-ray (EDX) spectroscopy, and solid state 1H−13C nuclear magnetic resonance spectroscopy (1H−13C NMR). The material contains 18.9% of Bi4O5Br2/BiOBr and was found to be effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under irradiation with 405 nm light. Lignin/Bi4O5Br2/BiOBr was able to decrease the dye concentration from 80 mg·L–1 to 12.3 mg·L–1 for RhB (85%) and from 80 mg·L–1 to 4.4 mg·L–1 for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for metal ions in aqueous solutions. The highest adsorption capacity was found after 2 hours of phases contact and reached 0.45 mmol·g–1 for Ni(II) ions (neutral media). The low cost, simplicity of the synthesis, good stability and ability to simultaneously photooxidize organic dyes and to adsorb metal ions, make the developed photoactive lignin/Bi4O5Br2/BiOBr composite a prospective material for textile wastewaters remediation

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Nanomaterial Synthesis in Ionic Liquids and Their Use on the Photocatalytic Degradation of Emerging Pollutants

Nanomaterials ◽

10.3390/nano11020411 ◽

2021 ◽

Vol 11 (2) ◽

pp. 411

Author(s):

Raquel Corchero ◽

Rosario Rodil ◽

Ana Soto ◽

Eva Rodil

Keyword(s):

Electron Microscopy ◽

Ionic Liquids ◽

Photoelectron Spectroscopy ◽

Bulk Material ◽

Degradation Mechanism ◽

Magnetic Nanocomposites ◽

Simple Method ◽

X Ray ◽

Emerging Pollutant ◽

Agcl Nanoparticles

The unique properties of ionic liquids make them suitable candidates to prepare nanoscale materials. A simple method that uses exclusively a corresponding bulk material and an ionic liquid—in this case, [P6,6,6,14]Cl—was used to prepare AgCl nanoparticles and AgCl@Fe3O4 or TiO2@Fe3O4 magnetic nanocomposites. The prepared nanomaterials were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, and X-ray photoelectron spectroscopy. The photodegradation of atenolol as a model pharmaceutical pollutant in wastewater was investigated under ultraviolet–visible light irradiation using the different synthesized nanocatalysts. In the presence of 0.75 g·L−1 AgCl nanoparticles, a practically complete degradation of 10 ppm of atenolol was obtained after 30 min, following pseudo-first-order reaction kinetics. The effect of different variables (concentrations, pH, oxidant agents, etc.) was analyzed. The recyclability of the nanocatalyst was tested and found to be successful. A degradation mechanism was also proposed. In order to improve the recovery stage of the nanocatalyst, the use of magnetic nanocomposites is proposed. Under the same experimental conditions, a slightly lower and slower degradation was achieved with an easier separation. The main conclusions of the paper are the suitability of the use of ionic liquids to prepare different nanocatalysts and the effectiveness of these at degrading an emerging pollutant in wastewater treatment.

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Palladium Nanocatalysts on Hydroxyapatite: Green Oxidation of Alcohols and Reduction of Nitroarenes in Water

Applied Sciences ◽

10.3390/app9194183 ◽

2019 ◽

Vol 9 (19) ◽

pp. 4183 ◽

Cited By ~ 24

Author(s):

Shokouhimehr ◽

Yek ◽

Nasrollahzadeh

Keyword(s):

Electron Microscopy ◽

Heterogeneous Catalyst ◽

Photoelectron Spectroscopy ◽

Pd Nanoparticles ◽

Structural Features ◽

Significant Loss ◽

X Ray ◽

Transmission Electron ◽

Palladium Nanocatalysts ◽

High Yields

A green procedure is described for supporting Pd nanoparticles on hydroxyapatite (HAP), which serves as a highly-stable heterogeneous catalyst displaying excellent activity for the aqueous expeditious reduction of nitroaromatics to the corresponding amines with sodium borohydride, and oxidation of primary and secondary alcohols by hydrogen peroxide with high yields and selectivities. The structural features of the prepared catalyst are confirmed by latest techniques including field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The reusability of the heterogeneous catalyst was affirmed in the aqueous reduction of nitrobenzene and oxidation of cycloheptanol for six consecutive runs without significant loss of catalytic activity.

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