Structural, Morphological and Electrochemical Examination of Carbon Spheres Wrapped by Maghemite Nanoparticles

In this work, pure carbon spheres (CSs) and Mn3O4 nanoparticles (NPs) embedded on carbon sphere were synthesized by hydrothermal method. The prepared CS/Mn3O4 was examined with structural, functional, and morphological properties by XRD, FTIR, and SEM analysis. The average grain size and crystalline size of Mn3O4 coated carbon sphere were found through morphological analysis. The element ratio, composition and distribution of the prepared Mn3O4 coated carbon sphere were analyzed through EDS and Mapping analysis. Electrochemical performance such as redox behavior, charge storage/discharge capacity and resistive nature of Mn3O4 /CSs was evaluated using cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopic analysis.

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ENHANCED SUPERCAPACITIVE PERFORMANCE OF NANOCRYSTALLINE Mn3O4 SYNTHESIZED BY HYDROTHERMAL METHOD

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i1.846 ◽

2015 ◽

Vol 12 (1) ◽

pp. 3919-3933 ◽

Cited By ~ 5

Author(s):

Dadamiah PMD Shaika ◽

P Rosaiah ◽

O M Hussain

Keyword(s):

Hydrothermal Method ◽

Reaction Temperature ◽

High Specific Capacitance ◽

Sem Analysis ◽

Arrhenius Behavior ◽

Supercapacitive Performance ◽

Average Grain Size ◽

Predominant Orientation ◽

Increasing Temperature ◽

Mn3o4 Nanoparticles

Mn3O4 nanoparticles have been successfully synthesized by a simple hydrothermal method at low temperatures. The processing conditions such as reaction temperature and time were optimized to synthesized phase pure nanocrystalline Mn3O4 with good electrochemical properties. The particles synthesized at a reaction temperature of 150°C for 12 h exhibited different characteristic peaks along with (211) predominant orientation which corresponds to tetragonal structure of Mn3O4 with space group I41/amd (141) and estimated crystallite size of 32 nm. The SEM analysis reveals that the octahedral shape of grains with an average grain size of 180 nm. The vibrational studies from Raman and FTIR measurements confirmed the microstructure and presence of Mn-O bonding. The conductivity of the product was increased with increasing temperature following the Arrhenius behavior with estimated activation energy of 0.37 eV. The supercapacitive performance of nanocrystalline Mn3O4 octahedrons in 1M Na2SO4 aqueous electrolyte exhibited a high specific capacitance of 348 Fg-1 at current density of 0.5 mAcm-2 and 70% capacitive retention even after 4000 cycles.

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Viability of Activated Carbon Derived from Polystyrene Sulphonate Beads as Electrical Double Layer Capacitors

C – Journal of Carbon Research ◽

10.3390/c7040082 ◽

2021 ◽

Vol 7 (4) ◽

pp. 82

Author(s):

Gbenro Babajide Folaranmi ◽

Anthony Ekennia ◽

Nkiruka Chidiebere Ani ◽

Richard Chukwuemeka Ehiri

Keyword(s):

Activated Carbon ◽

Double Layer ◽

Electrical Double Layer ◽

Electrochemical Impedance ◽

Carbon Sphere ◽

Potential Candidate ◽

Carbon Spheres ◽

Transfer Resistance ◽

X Ray ◽

Polystyrene Sulphonate

In this paper, a commercial polymeric resin precursor (polystyrene sulphonate beads) was used as a source of carbon spheres. The resin was pyrolyzed at different temperatures (700, 800, and 900 °C) and the resulting carbons were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). From the result of EIS, carbon spheres obtained at 700 °C (CS−700) have the least ohmnic resistance and highest capacitance. In furtherance, the resin was chemically activated with iron (III) chloride FeCl3·6H2O at different concentration (0.1 M, 0.3 M, and 0.5 M) and pyrolyzed at 700 °C to obtain activated carbon sphere namely (ACS 700−0.1, ACS 700−0.3, and ACS 700−0.5) in which the last digit of the samples denotes the concentration of FeCl3. Scanning electron microscope (SEM) showed that the carbon is of spherical shape; X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and X-ray photon electron spectroscopy (XPS) revealed successful introduction of Fe on the surface of the carbon. Out of all the activated carbon spheres, ACS 700−0.1 exhibited highest double layer capacitance of 9 µF cm−2 and lowest charge transfer resistance of 3.33 KΩ·cm2. This method shows that carbon spheres obtained from a polymeric source can be easily improved by simple resin modification and the carbon could be a potential candidate for an electrical double layer capacitor

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Obtaining and Corrosion Performance of Composite Zinc Coatings with Incorporated Carbon Spheres

Coatings ◽

10.3390/coatings10070665 ◽

2020 ◽

Vol 10 (7) ◽

pp. 665

Author(s):

Nelly Boshkova ◽

Kamelia Kamburova ◽

Nikola Koprinarov ◽

Mariana Konstantinova ◽

Nikolai Boshkov ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Composite Coating ◽

Electrochemical Impedance ◽

Steel Substrate ◽

Zinc Coating ◽

Pluronic F127 ◽

Carbon Sphere ◽

Carbon Spheres ◽

Scanning Electron

The present work describes one possible way to prepare a stable aqueous suspension of carbon sphere particles with a positive charge that is suitable for simultaneous electrodeposition with zinc on steel substrate. In order to stabilize the suspension against aggregation, tri-block amphiphilic copolymer Pluronic F127, which is commercially available, was adsorbed on the surface of carbon sphere particles. This polymer contained poly (ethylene oxide) blocks as hydrophilic segments and poly (propylene oxide) blocks as the hydrophobic part. Scanning electron microscopy and visual observations confirmed the stability of the obtained suspension. The carbon sphere particles were embedded into the zinc coating by the co-electrodeposition process. The surface morphology of the composite coating was investigated using scanning electron microscopy. The influence of the carbon spheres on the cathodic and anodic processes was evaluated with cyclic voltammetry studies. The electrochemical investigations were realized in a model corrosion medium (5% NaCl solution with pH 6.7) by application of selected methods such as polarization resistance, potentiodynamic polarization, and electrochemical impedance spectroscopy, which revealed higher protective ability of the composite coating against corrosion in an aggressive environment.

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Electrochemical Performance of Surfactant Assisted Hematite Nanoparticles by Chemical Synthesis Method

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.d1048.1284s419 ◽

2020 ◽

Vol 8 (4S4) ◽

pp. 140-143

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Electrochemical Impedance ◽

Synthesis Method ◽

Morphological Properties ◽

Chemical Route ◽

Prepared Nanoparticles ◽

Microscopy Technique ◽

Average Grain Size ◽

Scanning Electron

Fe2O3 nanoparticles were prepared by simple chemical route. The structural, functional, morphological properties of prepared nanoparticles were obtained by Powder X-ray Diffraction analysis, Fourier transform infrared spectroscopy, and Scanning Electron Microscopy analysis respectively. The average grain size of the prepared nanoparticles was calculated using the Scherrer formula. The functional groups and metal bonding were analyzed through FTIR analysis. The external morphology of the prepared nanomaterials was analyzed with scanning electron microscopy technique. Electrochemical property of the prepared nanomaterial was examined with the help of cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy.

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A Novel Electrochemical Impedance Spectroscopic Sensor for Determination of Saccharide Using Phenylboronic Acid as Molecular Recognition Element

CHINESE JOURNAL OF ANALYTICAL CHEMISTRY (CHINESE VERSION) ◽

10.3724/sp.j.1096.2013.20749 ◽

2013 ◽

Vol 41 (10) ◽

pp. 1537

Author(s):

Cong-Cong LI ◽

Xiao-Xia LI ◽

Xian-Wen LUO ◽

Hong-Lan QI

Keyword(s):

Molecular Recognition ◽

Electrochemical Impedance ◽

Phenylboronic Acid ◽

Recognition Element ◽

Molecular Recognition Element ◽

Electrochemical Impedance Spectroscopic

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Pitting Corrosion of Type 316L Stainless Steel Elaborated by the Selective Laser Melting Method: Influence of Microstructure

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05621-7 ◽

2021 ◽

Author(s):

V. Vignal ◽

C. Voltz ◽

S. Thiébaut ◽

M. Demésy ◽

O. Heintz ◽

...

Keyword(s):

Corrosion Behavior ◽

316L Stainless Steel ◽

Electrochemical Impedance ◽

Chemical Properties ◽

Passive Films ◽

First Order ◽

Average Grain Size ◽

Type 316L ◽

Pure Matrix ◽

Type 316L Stainless Steel

AbstractThe microstructure of two sets of 316L alloys (SLM and wrought structure) is determined using SPECTROMAXx stationary metal analyzer, FE-SEM/EDS and XRD. The physical–chemical properties of the passive films are also investigated by means of XPS, Auger after sputtering and electrochemical impedance spectroscopy measurements. Differences and similarities between the two sets of alloys are then identified. The corrosion behavior of alloys is investigated in NaCl solution at the macro- and microscale (microcapillary technique). It was found that the inclusion/particles cleanliness is the first-order parameter explaining differences between 316L(WS) and 316L(SLM). In the absence of particles (pure matrix), the two sets of alloys have the same corrosion behavior. Residual stresses, the average grain size, the PREN and the passive films properties are of second order.

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Monitoring microbial growth on a microfluidic lab-on-chip with electrochemical impedance spectroscopic technique

Biomedical Microdevices ◽

10.1007/s10544-021-00564-1 ◽

2021 ◽

Vol 23 (2) ◽

Author(s):

Subhan Shaik ◽

Aarthi Saminathan ◽

Deepak Sharma ◽

Jagdish A Krishnaswamy ◽

D Roy Mahapatra

Keyword(s):

Microbial Growth ◽

Electrochemical Impedance ◽

Spectroscopic Technique ◽

Lab On Chip ◽

On Chip ◽

Electrochemical Impedance Spectroscopic

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Unexpected Link between the Template Purification Solvent and the Structure of Titanium Dioxide Hollow Spheres

Catalysts ◽

10.3390/catal11010112 ◽

2021 ◽

Vol 11 (1) ◽

pp. 112

Author(s):

Tamás Gyulavári ◽

Kata Kovács ◽

Klára Magyari ◽

Kornélia Baán ◽

Anna Szabó ◽

...

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Phase Composition ◽

Anatase Phase ◽

Hollow Spheres ◽

Rutile Phase ◽

Carbon Sphere ◽

Carbon Spheres ◽

Carbonate Species ◽

Determining Factor

Carbon spheres were applied as templates to synthesize titanium dioxide hollow spheres. The templates were purified with either ethanol or acetone, and the effects of this treatment on the properties of the resulting titania were investigated. The photocatalytic activity of the catalysts was measured via the decomposition of phenol model pollutant under visible light irradiation. It was found that the solvent used for the purification of the carbon spheres had a surprisingly large impact on the crystal phase composition, morphology, and photocatalytic activity. Using ethanol resulted in a predominantly rutile phase titanium dioxide with regular morphology and higher photocatalytic activity (r0,phenol = 3.9 × 10−9 M∙s−1) than that containing mainly anatase phase prepared using acetone (r0,phenol = 1.2 × 10−9 M∙s−1), surpassing the photocatalytic activity of all investigated references. Based on infrared spectroscopy measurements, it was found that the carbon sphere templates had different surface properties that could result in the appearance of carbonate species in the titania lattice. The presence or absence of these species was found to be the determining factor in the development of the titania’s properties.

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Platinum nanoparticles partially-embedded into carbon sphere surfaces: a low metal-loading anode catalyst with superior performance for direct methanol fuel cells

Journal of Materials Chemistry A ◽

10.1039/c7ta06700c ◽

2017 ◽

Vol 5 (37) ◽

pp. 19857-19865 ◽

Cited By ~ 26

Author(s):

Kui Li ◽

Zhao Jin ◽

Junjie Ge ◽

Changpeng Liu ◽

Wei Xing

Keyword(s):

Fuel Cells ◽

Platinum Nanoparticles ◽

Direct Methanol Fuel Cells ◽

Pt Nanoparticles ◽

Superior Performance ◽

Carbon Sphere ◽

Carbon Spheres ◽

Anode Catalyst ◽

Direct Methanol ◽

Methanol Fuel Cells

A robust architecture, consisting of Pt nanoparticles partially-embedded in carbon spheres with low loading, brings about outstanding electrocatalytic performance in DMFCs.

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