scholarly journals Physicochemical and Electrochemical Characterization of Electropolymerized Polydopamine Films: Influence of the Deposition Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1964
Author(s):  
Julian Kund ◽  
Sven Daboss ◽  
Tommaso Marchesi D’Alvise ◽  
Sean Harvey ◽  
Christopher V. Synatschke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Deposition Process ◽  
Dip Coating ◽  
Adhesion Forces ◽  
Applied Potential ◽  
Experimental Conditions ◽  
Transfer Resistance

Polydopamine (PDA) is a synthetic eumelanin polymer which is, to date, mostly obtained by dip coating processes. In this contribution, we evaluate the physical and electrochemical properties of electrochemically deposited PDA films obtained by cyclic voltammetry or pulsed deposition. The obtained PDA thin films are investigated with respect to their electrochemical properties, i.e., electron transfer (ET) kinetics and charge transfer resistance using scanning electrochemical microscopy and electrochemical impedance spectroscopy, and their nanomechanical properties, i.e., Young’s modulus and adhesion forces at varying experimental conditions, such as applied potential or pH value of the medium using atomic force microscopy. In particular, the ET behavior at different pH values has not to date been investigated in detail for electrodeposited PDA thin films, which is of particular interest for a multitude of applications. Adhesion forces strongly depend on applied potential and surrounding pH value. Moreover, force spectroscopic measurements reveal a significantly higher percentage of polymeric character compared to films obtained by dip coating. Additionally, distinct differences between the two depositions methods are observed, which indicate that the pulse deposition process leads to denser, more cross-linked films.

Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

2016 ◽  
Vol 724 ◽  
pp. 87-91 ◽  
Author(s):  
Chang Su Kim ◽  
Yong Hoon Cho ◽  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Ball Milling ◽  
Carbon Coating ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

scholarly journals Electrochemical Characterization of CVD-Grown Graphene for Designing Electrode/Biomolecule Interfaces

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 241
Author(s):  
Keishu Miki ◽  
Takeshi Watanabe ◽  
Shinji Koh
Keyword(s):  
Electrochemical Properties ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Charge Transfer Resistance ◽  
Monolayer Graphene ◽  
Transfer Resistance ◽  
Graphene Electrode ◽  
Before And After ◽  
Modified Graphene

In research on enzyme-based biofuel cells, covalent or noncovalent molecular modifications of carbon-based electrode materials are generally used as a method for immobilizing enzymes and/or mediators. However, the influence of these molecular modifications on the electrochemical properties of electrode materials has not been clarified. In this study, we present the electrochemical properties of chemical vapor deposition (CVD)-grown monolayer graphene electrodes before and after molecular modification. The electrochemical properties of graphene electrodes were evaluated by cyclic voltammetry and electrochemical impedance measurements. A covalently modified graphene electrode showed an approximately 25-fold higher charge transfer resistance than before modification. In comparison, the electrochemical properties of a noncovalently modified graphene electrode were not degraded by the modification.

Comparison of the Photocatalytic and Photoelectrocatalytic Decolorization of Methyl Orange on Sputtered TiO2 Thin Films

2005 ◽  
Vol 60 (11) ◽  
pp. 1158-1167 ◽  
Author(s):  
Yuh-Fan Su ◽  
Tse-Chuan Chou
Keyword(s):  
Thin Films ◽  
Methyl Orange ◽  
Counter Electrode ◽  
Electrochemical Impedance ◽  
Bandgap Energy ◽  
Applied Potential ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Structure Morphology ◽  
Vis Spectroscopy

Correlations between the photocatalytic and photoelectrocatalytic decolorization of methyl orange, using TiO2 thin films sputtered under various conditions, were made. Three types of systems, namely: two photocatalytic systems, one with and one without a Pt counter electrode, and a third with a Pt counter electrode having an applied potential, were used to evaluate photocatalytic activity.The crystal structure, morphology, bandgap energy, flatband potential, and the resistances of the TiO2 films were characterized by X-ray diffraction, scanning electron microscopy, UV/vis spectroscopy, a photocurrent method, and electrochemical impedance spectroscopy, respectively. The results showed that the decolorization of methyl orange only occurred on the anode of the TiO2/Ti electrode and that the decolorization rate increased 67% when the photocatalyst was coupled to a Pt electrode (0 V applied potential), and 275% when connected with the Pt cathode and 1 V vs. Ag/AgCl applied potential. The benefits of high crystallinity, a high quantity of the anatase, and a more negative flatband potential were found in the photocatalytic reaction, whereas the resistance of the film was the main factor affecting the photoelectrocatalytic activity.

Effect of Cl- Content, pH Value and CO2 on Electrochemical Corrosion Features of Cr15 Super Martensitic Stainless Steel

2013 ◽  
Vol 738 ◽  
pp. 92-96
Author(s):  
Jin Ming Long ◽  
Quan Bin Liu ◽  
Kun Yu Zhao ◽  
Qi Long Yong ◽  
Jie Su
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Charge Transfer Resistance ◽  
Uniform Corrosion ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Pitting Potential ◽  
Super Martensitic Stainless Steel

The corrosion behavior of a Cr15 super martensitic stainless steel (Cr15 SMSS) was investigated in NaCl solutions by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Effects of Cl-content, pH value and saturated CO2on corrosion were sdudied. It was found that the parameters of maintaining passivity current density (ip), the critical pitting potential (Eb) and charge transfer resistance (Rt) of Cr15 SMSS varied widely under different conditions. The corrosion resistance of Cr15 SMSS decrease with increasing Cl-concentration and lowering pH value. BothipandEbincrease for Cr15 SMSS in CO2-saturated NaCl solution, which verified that the CO2in NaCl solution can result in lower pitting sensitivity and higher uniform corrosion rate to Cr15 SMSS.

scholarly journals Influence of pH on the Properties of Chemical Bath Deposited Ni4S3 Thin Films

1970 ◽  
Vol 46 (2) ◽  
pp. 243-246 ◽  
Author(s):  
K Anuar ◽  
WT Tan ◽  
N Saravanan ◽  
SM Ho
Keyword(s):  
Thin Films ◽  
Ph Value ◽  
Sodium Thiosulfate ◽  
Deposition Process ◽  
Xrd Analysis ◽  
Nickel Sulphide ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force ◽  
Influence Of Ph

The Ni4S3 thin films were prepared by chemical bath deposition method. The chemical bath contained nickel sulphate and sodium thiosulfate which supplied the Ni2+ and S2- ions, respectively. The structure and morphology of the films were studied using X-ray diffraction and atomic force microscopy technique, respectively. Absorbance spectra data of the films were obtained by UV-Vis spectrophotometer. The influence of pH was investigated in order to determine the best conditions for deposition process. The number of peaks attributable to cubic structure of Ni4S3 increased to three as the pH was increased to 2.5 according to XRD analysis. In optical absorption spectra, we found that the highest absorbance value was obtained for the films deposited at pH 2.5. Also, the AFM image revealed that the films were smooth, compact and uniform at this pH value. The band gap of films ranged from 0.85 to 1.8 eV depending upon the pH value. Key words: Nickel sulphide; Thin films; Solar cells; Semiconductor. DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8192 Bangladesh J. Sci. Ind. Res. 46(2), 243-246, 2011

scholarly journals Synthesis and Study of CdS Thin Films Prepared with Different KMnO4 Activation Time

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Sarveswaran Thangarajan ◽  
Gopinathan Chellachamy ◽  
Saravanakumar Kulendran ◽  
Pandi Pitchai ◽  
Mahalakshmi Kandasamy
Keyword(s):  
Thin Films ◽  
Chemical Bath Deposition ◽  
Ph Value ◽  
Deposition Process ◽  
Activation Time ◽  
Glass Substrates ◽  
Cds Thin Film ◽  
Cds Thin Films ◽  
Cbd Method ◽  
Cds Film

The growth and properties of cadmium sulfide (CdS) thin films were prepared in a controlled manner using chemical bath deposition (CBD) method for different KMnO4 activation time such as 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min on glass substrates. CdS thin films are deposited on KMnO4 activated glass substrates at 85°C with pH value of 10 for 30 min deposition time. In the chemical bath deposition (CBD) technique, KMnO4 activation time plays an important role in the growth of the CdS film. The structure of the CdS film changes with respect to the rate of deposition. The size of the particles is affected by the nucleation rate if the solution does not contain the constant number of Cd2+ and S2− ions throughout the deposition process. This change in structure of CdS is confirmed by the XRD, SEM, and AFM analysis, and the ion-by-ion nucleation growth is also examined. The optical property of the prepared CdS thin film is scrutinized using UV-Vis-NIR absorption analysis.

Synthesis and Electrochemical Properties of Polypyrrole Conducting Polymer in Sheath like Nanotube Arrays Structured over TiO2 for Supercapacitor Energy Storage Devices

2015 ◽  
Vol 1749 ◽  
Author(s):  
Navjot K. Sidhu ◽  
A.C. Rastogi
Keyword(s):  
Energy Storage ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Nanotube Arrays ◽  
Energy Storage Devices ◽  
Transfer Resistance ◽  
Capacitance Density ◽  
Electrically Conducting ◽  
Supercapacitor Energy Storage

ABSTRACTThe vertical TiO2 nanotube arrays constituting the core of 3-D nanoscale electrode architecture were synthesized over Ti sheet by anodization. Such formed TiO2 nanotubes are electrically conducting and amorphous as confirmed by XRD studies. Nanotube morphology is affected by water content and in the present study, close-packed 3-4 μm long TiO2 nanotube arrays of 45-50 nm diameter are formed with 2% water as revealed by the transmission and scanning electron microscopy. The redox active polypyrrole sheath is created by ultra-short pulsed current electropolymerization. Electrochemical properties of the 3-D nanoscaled TiO2 nanotube core-polypyrrole sheath electrodes relevant to the energy storage were investigated using cyclic voltammetry (CV) plots, electrochemical impedance spectroscopy (EIS), Charge discharge (CD) tests. High areal capacitance density of 48 mF cm-2 and low charge transfer resistance 12 Ω cm-2 with least ion diffusion limitation are realized at optimized polypyrrole sheath thickness. The Raman spectra studies reveal anion at specific chain locations involve in the redox process.

scholarly journals Study of solvent effect on structural and photoconductive behavior of ternary chalcogenides InBiS3-In2S3-Bi2S3 composite thin films deposited via AACVD

2019 ◽  
Vol 42 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Umar Daraz ◽  
Tariq Mahmood Ansari ◽  
Shafique Ahmad Arain ◽  
Muhammad Adil Mansoor ◽  
Muhammad Mazhar
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Visible Region ◽  
Chloroform Solution ◽  
Photocurrent Density ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
X Ray ◽  
Wide Range

Abstract In the present work ternary composite InBiS3-In2S3-Bi2S3 (IBS) thin films are developed using a homogeneous mixture of precursors [Bi(S2CN(C2H5)2)3]2 (1) and [In(S2CNCy2)3]‧2py (2), separately in toluene and chloroform solutions at 500°C under an inert atmosphere of argon gas via aerosol assisted chemical vapor deposition (AACVD) technique. The phase purity, chemical composition and morphological study of both the films deposited from toluene and chloroform solutions are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Field emission scanning electron microscopy (FESEM). The surface morphology showed rod like structure of the films developed from toluene while the films grown from chloroform solution give flake like shapes. The UV-visible spectroscopy explicated that the thin films developed from toluene and chloroform solutions show wide range absorption in whole visible region. Linear Scan voltammetry results show that both the films give negligible dark current, however, the films fabricated from toluene solution give a sharp steep curve with maximum photocurrent density of 2.3 mA‧cm-2 at 0.75 V vs Ag/AgCl/3M KCl using 0.05 M sodium sulphide solution under AM 1.5 G illumination (100 mW‧cm-2), while the film grown from chloroform generates a photocurrent density of 2.1 mA‧cm-2 under similar conditions. The LSV outcomes are further supported by electrochemical impedance spectroscopy (EIS) that gives charge transfer resistance (Rct) value of 8,571 Ω for the films developed from toluene as compared to films fabricated from chloroform with Rct value of 12,476 Ω.

Effects of Ni Electroless Plating on Electrochemical Properties of Mg2 Ni Hydrogen Storage Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 681-684
Author(s):  
Yougen Tang ◽  
Yijun Xu ◽  
Zhuguang Lu ◽  
Bo Yun Huang
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Diffusion Resistance ◽  
Cyclic Voltammogram ◽  
Hydrogen Storage Alloys ◽  
Transfer Resistance ◽  
Atom Diffusion ◽  
Surface Morphologies

Effects of nickel coating on electrochemical properties of Mg2Ni hydrogen storage alloys were presented in this paper. X-ray diffraction ( XRD) and scanning electron microscope (SEM) were employed to examine the crystal structure and surface morphologies of the as-obtained bare and Ni-coated Mg2Ni alloys and their electrochemical properties were characterized by cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). Results showed that Ni coating not only decreased charge transfer resistance, but also decreased H atom diffusion resistance for Mg2Ni alloys. It was also found that Ni coating effectively improved the discharge capacity.

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