scholarly journals Preparation of PPy-WO3 Nano-composite for Supercapacitor Applications

2021 ◽  
pp. 1503-1512
Author(s):  
Firas J. Hameed ◽  
Isam M. Ibrahim
Keyword(s):  
Figure Of Merit ◽  
Electrochemical Impedance ◽  
Xrd Analysis ◽  
Chemical Oxidation ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Nano Composite ◽  
Triclinic Phase ◽  
Supercapacitor Applications ◽  
Structure Properties

In this work, polypyrrole (PPy) composites were chemically prepared by a chemical oxidation method. Also, Tungsten Trioxide (WO3) nanoparticles were prepared and added in certain proportions to PPy. The structure properties were studied for the polypyrole and tungesten trioxide separately before mixing them together. The X-ray diffraction (XRD) analysis revealed a hexagonal WO3 and a triclinic PPy. It was observed that the nano-composite prepared by the addition of WO3  with 10 and 20% volume ratios to PPy shows a triclinic phase with the presence of hexagons. The molecular structures of PPy, WO3, and PPy–WO3 nano composites were depicted by Fourier-transform infrared spectroscopy (FTIR) in the scope of 400–4000 cm-1. The supercapcitors of PPy and PPy-WO3 were examined by calculating the figure of merit of the electrode (PPy and PPy-WO3) using cyclic voltammetry (CV), galvanostatic charge and discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. It was found that the highest value of capacity (266.62 F/g) is obtained at 20% WO3 ratio.                                        

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

Preparation of Cu2ZnSnS4 Thin Films by Successive Ionic Layer Adsorption and Reaction (SILAR) Method for Supercapacitor Applications

2020 ◽  
Vol 20 (10) ◽  
pp. 6235-6244 ◽  
Author(s):  
A. Murugan ◽  
V. Siva ◽  
A. Shameem ◽  
S. Asath Bahadur
Keyword(s):  
Thin Films ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Silar Method ◽  
Layer Adsorption ◽  
Diffraction Patterns ◽  
Czts Thin Films ◽  
Supercapacitor Applications ◽  
Ionic Layer

The Cu2ZnSnS4 (CZTS) thin films have been prepared at different deposition cycles, deposited on a glass substrate by successive ionic layer adsorption and reaction (SILAR) method followed by the annealing process at elevated temperature. The investigations on the films have been carried out to understand and confirm its structure, functional group present, crystalline morphology, optical and electrochemical behavior. The powder X-ray diffraction patterns recorded indicate that the deposited films are formed in the tetragonal structure. Other parameters like grain size, dislocation density, and microstrain are also calculated. The uniform surface of the films with spherical shaped morphology has been observed by Scanning Electron Microscopy, and the elemental compositions have been confirmed by EDAX. Electrochemical behavior such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge analysis have been carried out by electrochemical workstation. The modified electrode exhibits maximum specific capacitance value as 416 F/g for a pure sample. Optical studies have shown that the band gaps are estimated between 1.40 eV and 1.57 eV.

scholarly journals Optical and Electrochemical Applications of Li-Doped NiO Nanostructures Synthesized via Facile Microwave Technique

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2961 ◽  
Author(s):  
Aarti S. Bhatt ◽  
R. Ranjitha ◽  
M. S. Santosh ◽  
C. R. Ravikumar ◽  
S. C. Prashantha ◽  
...  
Keyword(s):  
Optical Band Gap ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Technique ◽  
Electro Optic ◽  
Li Ion ◽  
Supercapacitor Applications

Nanostructured NiO and Li-ion doped NiO have been synthesized via a facile microwave technique and simulated using the first principle method. The effects of microwaves on the morphology of the nanostructures have been studied by Field Emission Spectroscopy. X-ray diffraction studies confirm the nanosize of the particles and favoured orientations along the (111), (200) and (220) planes revealing the cubic structure. The optical band gap decreases from 3.3 eV (pure NiO) to 3.17 eV (NiO doped with 1% Li). Further, computational simulations have been performed to understand the optical behaviour of the synthesized nanoparticles. The optical properties of the doped materials exhibit violet, blue and green emissions, as evaluated using photoluminescence (PL) spectroscopy. In the presence of Li-ions, NiO nanoparticles exhibit enhanced electrical capacities and better cyclability. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results show that with 1% Li as dopant, there is a marked improvement in the reversibility and the conductance value of NiO. The results are encouraging as the synthesized nanoparticles stand a better chance of being used as an active material for electrochromic, electro-optic and supercapacitor applications.

Temperature Controlled Synthesis of Ce–MnO2 Nanostructure: Promising Electrode Material for Supercapacitor Applications

2020 ◽  
Vol 12 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Rajesh Rajagopal ◽  
Kwang-Sun Ryu
Keyword(s):  
Electrode Material ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Supercapacitor Application ◽  
Structural Details ◽  
Different Temperatures ◽  
Microscope Technique ◽  
Supercapacitor Applications

The objective of this study was to prepare Ce–MnO2 nanostructure composite as an electrode material for supercapacitor application. Ce–MnO2 nanostructure composite was synthesized by facile hydrothermal method at different temperatures. Structural details of pure and Ce–MnO2 nanostructure composite were studied using powder X-ray diffraction technique. The formation of flower like structure and strong interaction with Ce and MnO2 were confirmed by field emission electron microscope technique. Their electrochemical performances were elucidated by using cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy techniques. Nearly rectangular shaped cyclic voltagram was observed for synthesized Ce–MnO2 nanostructure composite electrode, indicating the existence of electric double layer capacitance nature. Ce–MnO2 (130) nanostructure composite exhibited high specific capacitance value of 147.25 F/g at applied current density of 1 A/g in 1 M Li2SO4 aqueous electrolyte. Furthermore, resistive and capacitive behaviors of these electrodes were studied from Nyquist and bode diagrams within frequency range of 10 mHz to 100 kHz.

Influence of Plasticizers on the Electrical Conductivity of Polyacrylonitrile (PAN)/Lithium-Montmorillonite (Li-MMT) Polymer Composite Electrolyte

2017 ◽  
Vol 894 ◽  
pp. 89-93
Author(s):  
Mitch Irene Kate N. Galvan ◽  
Leslie Joy L. Diaz
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composite ◽  
Electrochemical Impedance ◽  
Current Trend ◽  
Xrd Analysis ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Composite Electrolyte ◽  
X Ray

With the current trend of miniaturization and portability of electronic gadgets, the development of polymer composite electrolyte (PCE) gained much research interest. In this study PAN matrix was plasticized with various dimethyl formamide (DMF)/ propylene carbonate (PC) ratios. X-ray diffraction (XRD) analysis revealed that both DMF and PC reduce the crystallinity of PAN. Yet, films with higher amount of PC caused much decrease in crystallinity, which is indicated by lowering of full with at half maximum (FWHM) at the utmost 57% when the DMF/PC ratio is 1:2. Differential scanning calorimetry (DSC) analysis also revealed that glass transition temperature (Tg) of PAN decreased from 83.34°C to 50.27°C when plasticized with pure DMF and to temperature lower than ambient condition when PC alone was used. Upon incorporation of 15 wt% Li-MMT, PCEs with pure DMF exhibited the highest electrical conductivity, which is 3.6x10-8 S/cm based on electrochemical impedance spectroscopy (EIS). This suggests that the electrical conductivity is not dictated by the decrease on polymer host crystallinity alone. The type of plasticizer and appropriate combination was shown to have an effect wherein the plasticizer that causes higher degree of solvation and has lower boiling point is thought to provide more hopping sites for electrons due to higher amount of broken bonds in the nitrile group of PAN.

Effects of Different Concentration in (w/v)% of Carboxymethyl Iota-Carrageenan Based Green Polymer Electrolyte

2015 ◽  
Vol 1107 ◽  
pp. 205-210
Author(s):  
Fatihah Najirah Jumaah ◽  
Azizan Ahmad ◽  
Hussein Hanibah ◽  
Nadhratun Naiim Mobarak ◽  
M.A. Ghani
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Electrochemical Impedance ◽  
Amorphous Region ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Volume Percentage ◽  
Casting Technique ◽  
Solution Casting Technique ◽  
Green Polymer

The effect of different concentrations in weight per volume percentage, (w/v)% of iota-carrageenan and carboxymethyl-iota carrageenan used as the green polymer electrolyte has been studied. The polymer electrolyte films were prepared by solution casting technique. Different concentration in the range from 1.0 – 6.0 (w/v)% were dissolved in fix volume of acetic acid which act as solvent. The films have been analyzed through attenuated Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) measurement and electrochemical impedance spectroscopy (EIS). The EIS results showed that the ionic conductivity increased as the concentration of the polymer increases. In comparison between iota-carrageenan and carboxymethyl iota-carrageenan, carboxymethyl-iota carrageenan showed better results due to the presence of more active site. The highest conductivity achieved by iota-carrageenan and carboxymethyl iota-carrageenan were 3.45 × 10-6S cm-1and 9.57 × 10-4S cm-1at the concentration 3.0 and 4.0 (w/v)% , respectively. From the FTIR spectra, it depicts that the intensity of significant peaks of ether and carboxylate group increases as the concentration of polymer increases. The XRD analysis showed that as the concentration of polymer increase, the amorphous region in the films would be enhanced. This study showed that the concentration play significant role in the ionic conductivity improvement.

Corrosion process of D32 steel used for offshore oil platform in splash zone

2015 ◽  
Vol 63 (1) ◽  
pp. 56-64 ◽  
Author(s):  
JianGuo Liu ◽  
Zili Li ◽  
Yantao Li ◽  
BaoRong Hou
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Steel Structure ◽  
Chemical Oxidation ◽  
Corrosion Process ◽  
Splash Zone ◽  
X Ray Diffraction ◽  
Content Type ◽  
Reduction Processes ◽  
Offshore Oil

Purpose – This paper aims to study the corrosion behavior of D32 steel suffered to marine splash zone. Type D32 structural steel has good mechanical properties and is commonly used for offshore oil platform construction in China. To ensure the safety of marine steel structure, it is important to study the corrosion process of D32 steel in the splash zone. Design/methodology/approach – The corrosion behavior of D32 steel in splash zone environments was studied using polarization curves and electrochemical impedance spectroscopy. The electrochemical results were obtained from the corroded steel samples exposed in the splash zone of a bespoke simulate device, while corrosion morphologies and corrosion products of the steel samples were characterized using scanning electron microscopy and X-ray diffraction. Findings – In wet–dry cyclic exposure, the reaction was a self-perpetuating process of chemical oxidation and electrochemical reduction. The rust itself took part in the reduction processes and, hence, increased the corrosion rate of the steel samples. Originality/value – Finally, the corrosion process of D32 steel in splash zone is considered.

Synthesis, Characterization, and Theoretical Studies of cis-Dichloridobis(8-quinolinethiolato)tin(IV) and bis(8-Sulfanylquinolinium) Hexachloridostannate(IV) Derivatives

2020 ◽  
Vol 73 (12) ◽  
pp. 1128
Author(s):  
Rajesh Deka ◽  
Arup Sarkar ◽  
Harkesh B. Singh ◽  
Peter C. Junk ◽  
David R. Turner ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Dft Calculations ◽  
Single Crystal ◽  
Dimethyl Sulfoxide ◽  
Molecular Structures ◽  
Theoretical Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Characterisation ◽  
Structure Properties

The structural characterisation of bis(8-sulfanylquinolinium) hexachloridostannate(iv) (2) is reported and the variable reaction behaviour of this compound in different solvents has been explored. In particular, attempted recrystallization of 2 from chloroform and dichloromethane affords two polymorphs of cis-dichloridobis(8-quinolinethiolato)tin(iv), 3m and 3t, respectively. Attempted recrystallization of 2 from methanol gives crystals of 8,8′-dithiodiquinolinium hexachloridostannate(iv) 4. When 2 is dissolved in dimethyl sulfoxide in the presence of air, it undergoes oxidation to afford diquinolinyl-8,8′-disulfide 5. The molecular structures of the isolated compounds 2–4 are unambiguously authenticated by single crystal X-ray diffraction studies. The electronic structure properties of all the isolated compounds 2–4 are thoroughly studied by DFT calculations.

Effect of Disintegration Process on the Properties of Bacterial Cellulose Foam

2020 ◽  
Vol 851 ◽  
pp. 86-91
Author(s):  
Heru Suryanto ◽  
Muhamad Muhajir ◽  
Tito Arif Sutrisno ◽  
Uun Yanuhar ◽  
Redyarsa D. Bintara
Keyword(s):  
Bacterial Cellulose ◽  
High Speed ◽  
Freeze Drying ◽  
Xrd Analysis ◽  
Skin Extract ◽  
X Ray Diffraction ◽  
Disintegration Process ◽  
High Pressure Homogenizer ◽  
Sem Morphology ◽  
Structure Properties

Bacterial cellulose (BC) has applied as a versatile biomaterial in a wide variety of applications, such as biomedical devices, acoustics, electronics, and paper products. The controlling of the procedure could significantly improve the chemical and structure properties of the BC foams. This study aims to compare the features of BC foam that synthesized from BC disintegrated by a high-speed blender (HSB) and high-pressure homogenizer (HPH). The methods are the synthesis of BC using pineapple skin extract, disintegration process using both HSB and HPH following by freeze-drying process and characterization using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and FTIR. The results show that freeze-drying to the pellicle did not produce a foam structure of BC. SEM morphology indicates that the disintegration process using HPH produces a better porous BC foam compared than HBS process. XRD analysis shows three peaks associated with the structure of BC, which are at 14.47°, 16.85°, and 22.69°. The crystalline structure of BC foam produced from HPH process has higher than BC foam produced from HBS process. FTIR analysis shows that there is a new peak find out in BC foam after the disintegration process.

Preparation and characterization of lead ruthenate based composite cathodes for SOFC applications

2004 ◽  
Vol 835 ◽  
Author(s):  
Vincenzo Esposito ◽  
Enrico Traversa ◽  
Eric D. Wachsman
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Xrd Analysis ◽  
Composite Electrodes ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Composite Cathodes ◽  
Different Temperatures ◽  
Eis Measurements

ABSTRACTNanometric pyrochlore lead ruthenate (Pb2Ru2O6.5) powders were prepared using a new chemical route as a possible candidate for cathode materials in solid oxide fuel cells (SOFCs). Pb2Ru2O6.5 was mixed with yttria-stabilized zirconia (YSZ) and erbia-stabilized bismuth oxide (ESB) to fabricate porous composite electrodes. Pure pyrochlore or composite electrodes were deposited as thick films onto YSZ and ESB electrolytes. Powders and films were analyzed using X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FE-SEM). Electrochemical features of the electrodes were investigated using electrochemical impedance spectroscopy (EIS) measurements at different temperatures in air for symmetric cells. The composite electrodes were compared to single Pb2Ru2O6.5 phase electrodes to evaluate the effect on polarization of the addition of the pure ionic conductor phase in the electrodes.

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