Pd Nanoparticles Self-Assembled on Fluorine-Modified MWCNTs as Electro-Catalysts for Methanol Electro-Oxidation

Multi-walled carbon nanotubes (MWCNTs) were modified by hydrogen fluoride (HF) in a simple method. With the help of fluorine, Pd nanoparticles (3.9[Formula: see text]nm) synthesized by a one-step photochemical reduction were uniformly self-assembled on the active sites of functionalized MWCNTs and a new catalyst (Pd/HF-MWCNT) was obtained. UV–Vis absorption spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used. The results demonstrated that –F groups were introduced onto the surface of MWCNTs and C–F chemical bonds were formed. In addition, the electronic structure of Pd was changed. Pd–F coordination bond maybe formed between F atom and Pd atom. Cyclic voltammetry and chronoamperometry tests indicated that electro-catalytic activity of Pd/HF-MWCNTs catalyst for methanol in alkaline medium was about 1.6 times higher than that of the commercial Pd/C (JM) catalyst at the same condition. This new functionalized method has the advantages of simple step and safe operation. It is very significant to improve the wide application of MWCNTs and the commercial development of direct methanol fuel cells (DMFCs).

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Electroless Synthesis of 1.4 nm Pd and Pt Nanoparticles on Self-Assembled Rosette Nanotubes

MRS Proceedings ◽

10.1557/opl.2011.69 ◽

2011 ◽

Vol 1301 ◽

Cited By ~ 1

Author(s):

Rahul Chhabra ◽

Hicham Fenniri

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Pt Nanoparticles ◽

Hierarchical Organization ◽

X Ray ◽

Force Microscopy ◽

Rosette Nanotubes ◽

Atomic Force ◽

Transmission Electron ◽

Self Assembled

ABSTRACTElectroless synthesis and hierarchical organization of 1.4 nm Pd and Pt nanoparticles (NPs) on self-assembled Rosette Nanotubes (RNTs) is described. The nucleated NPs are nearly monodisperse and reveal supramolecular organizations guided by RNT templates. Interestingly, the narrow size distribution is attributable to unique templating behavior of RNTs. The resulting metal NP-RNT composites were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). X-ray Photoelectron Spectroscopy (XPS) was also performed to confirm the nature and composition of RNT-templated NPs.

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Synthesis and Characterization of Heterostructure Pd/Bi2WO6 Nanocomposites with Enhanced Properties of Visible-Light-Driven Photocatalyst

10.21203/rs.3.rs-512226/v1 ◽

2021 ◽

Author(s):

Anukorn Phuruangrat ◽

Jarupat Teppetcharat ◽

Panudda Patiphatpanya ◽

Phattranit Dumrongrojthanath ◽

Somchai Thongtem ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Pd Nanoparticles ◽

Cubic Phase ◽

Xenon Lamp ◽

Visible Absorption ◽

X Ray ◽

Visible Light Driven ◽

20 Nm

Abstract Heterostructure Pd/Bi2WO6 nanocomposites were successful synthesized in ethylene glycol by microwave-assisted deposition method at 300 W for 10 min. Effect of the loaded Pd on phase, composition, morphology and visible-light-driven photocatalytic properties of Bi2WO6 was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fast-Fourier-Transform (FFT) diffraction, UV-visible absorption and X-ray photoelectron spectroscopy (XPS). In this research, good distribution of cubic phase of spherical Pd nanoparticles with particle size of 15–20 nm supported on orthorhombic Bi2WO6 thin nanoplates. The 10% Pd/Bi2WO6 nanocomposites reveal major metallic Pd0 species containing in Bi2WO6 sample. Microwave can be used to synthesize metallic Pd nanoparticles supporting on top of Bi2WO6 nanoplates. Photocatalytic activities of Bi2WO6 loaded with different weight contents of Pd were monitored through photodegradation of cationic rhodamine B (RhB) dye under visible light irradiation of a xenon lamp. The 10% Pd/Bi2WO6 nanocomposites have the highest photocatalytic activity because Pd nanoparticles as electron acceptors promote interfacial charge-transfer through Pd/Bi2WO6 heterojunction.

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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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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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Determination of the Size of Supported Pd Nanoparticles by X-ray Photoelectron Spectroscopy. Comparison with X-ray Diffraction, Transmission Electron Microscopy, and H2 Chemisorption Methods

The Journal of Physical Chemistry C ◽

10.1021/jp106956w ◽

2010 ◽

Vol 114 (39) ◽

pp. 16677-16684 ◽

Cited By ~ 67

Author(s):

R. Wojcieszak ◽

M. J. Genet ◽

P. Eloy ◽

P. Ruiz ◽

E. M. Gaigneaux

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Pd Nanoparticles ◽

X Ray Diffraction ◽

X Ray ◽

H2 Chemisorption ◽

Transmission Electron ◽

Supported Pd

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A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Pd Nanoparticles Modified Electrode

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.117-119.790 ◽

2011 ◽

Vol 117-119 ◽

pp. 790-794 ◽

Cited By ~ 2

Author(s):

Zhen Jing Zhuang

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Pd Nanoparticles ◽

Carbon Electrode ◽

Deposition Method ◽

Applied Potential ◽

Medium Ph ◽

X Ray ◽

Electrochemical Deposition Method ◽

Scanning Electron

Pd nanoparticles have been prepared on the surface of glassy carbon electrode (GCE) by electrochemical deposition method and applied for the nonenzymatic detection of H2O2. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to investigate the as-prepared Pd nanoparticles on the surface of GCE. The electrochemical properties of Pd nanoparticles modified GCE were also characterized by cyclic voltammetry and chronoamperometry. The results showed that Pd nanoparticles modified GCE had a favorable catalytic ability for the reduction of H2O2in PBS medium (pH=7.6). At an applied potential of -0.06 V, the nonenzymatic H2O2sensors produce high and reproducible sensitivity to H2O2with 52.45 μA/mmol۰dm–3. Linear responses were obtained over a concentration range from 0.15 mmol۰dm–3to 18 mmol۰dm–3with a detection limit of 25 μmol۰dm–3(S/N=3). Additionally, it exhibited a rapid response time (within 1s), which was much faster than some nonenzymatic H2O2sensors.

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

10.26434/chemrxiv.12993401.v1 ◽

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

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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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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Standing and Lying Ni(OH)2 Nanosheets on Multilayer Graphene for High-Performance Supercapacitors

Nanomaterials ◽

10.3390/nano11071662 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1662

Author(s):

Junming Xu ◽

Mengxia Tang ◽

Zhengming Hu ◽

Xiaoping Hu ◽

Tao Zhou ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Active Sites ◽

Electrode Materials ◽

High Current Density ◽

Growth Stages ◽

Electrochemical Performances ◽

Multilayer Graphene ◽

X Ray ◽

Hybrid Supercapacitors

For conventional synthesis of Ni(OH)2/graphene hybrids, oxygen-containing functional groups should be firstly introduced on graphene to serve as active sites for the anchoring of Ni(OH)2. In this work, a method for growing Ni(OH)2 nanosheets on multilayer graphene (MLG) with molecular connection is developed which does not need any pre-activation treatments. Moreover, Ni(OH)2 nanosheets can be controlled to stand or lie on the surface of MLG. The prepared hybrids were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The growth processes are suggested according to their morphologies at different growth stages. The enhanced electrochemical performances as supercapacitor electrode materials were confirmed by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. Ni(OH)2 nanosheets standing and lying on MLG show specific capacities of 204.4 mAh g−1 and 131.7 mAh g−1, respectively, at 1 A g−1 based on the total mass of the hybrids and 81.5% and 92.8% capacity retention at a high current density of 10 A g−1, respectively. Hybrid supercapacitors with as-prepared hybrids as cathodes and activated carbon as anode were fabricated and tested.

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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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