scholarly journals Electrochemical Characterization of Modified Glassy Carbon Electrodes for Non-Enzymatic Glucose Sensors

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7928
Author(s):  
Julia Maria Mazurków ◽  
Anna Kusior ◽  
Marta Radecka
Keyword(s):  
Glassy Carbon ◽  
Electrochemical Impedance ◽  
Glucose Sensors ◽  
X Ray Diffraction ◽  
Bare Glassy Carbon Electrode ◽  
Detection Mechanism ◽  
Glassy Carbon Electrodes ◽  
Copper Sulfides ◽  
Sensor Performance

The diversity of materials proposed for non-enzymatic glucose detection and the lack of standardized protocols for assessing sensor performance have caused considerable confusion in the field. Therefore, methods for pre-evaluation of working electrodes, which will enable their conscious design, are currently intensively sought. Our approach involved comprehensive morphologic and structural characterization of copper sulfides as well as drop-casted suspensions based on three different polymers—cationic chitosan, anionic Nafion, and nonionic polyvinylpyrrolidone (PVP). For this purpose, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy were applied. Subsequently, comparative studies of electrochemical properties of bare glassy carbon electrode (GCE), polymer- and copper sulfides/polymer-modified GCEs were performed using electrochemical impedance spectroscopy (EIS) and voltammetry. The results from EIS provided an explanation for the enhanced analytical performance of Cu-PVP/GCE over chitosan- and Nafion-based electrodes. Moreover, it was found that the pH of the electrolyte significantly affects the electrocatalytic behavior of copper sulfides, indicating the importance of OHads in the detection mechanism. Additionally, diffusion was denoted as a limiting step in the irreversible electrooxidation process that occurs in the proposed system.

scholarly journals Electrochemical Glucose Oxidation Using Glassy Carbon Electrodes Modified with Au-Ag Nanoparticles: Influence of Ag Content

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Nancy Gabriela García-Morales ◽  
Luis Alfonso García-Cerda ◽  
Bertha Alicia Puente-Urbina ◽  
Leonor María Blanco-Jerez ◽  
René Antaño-López ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Electrode Surface ◽  
Glucose Oxidation ◽  
Modified Electrodes ◽  
Alkaline Media ◽  
Carbon Electrodes ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Glassy Carbon Electrodes ◽  
Transmission Electron

This paper describes the application of glassy carbon modified electrodes bearing Aux-Agynanoparticles to catalyze the electrochemical oxidation of glucose. In particular, the paper shows the influence of the Ag content on this oxidation process. A simple method was applied to prepare the nanoparticles, which were characterized by transmission electron microscopy, Ultraviolet-Visible spectroscopy, X-ray diffraction spectroscopy, and cyclic voltammetry. These nanoparticles were used to modify glassy carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The modified glassy carbon electrodes are highly sensitive to glucose oxidation in alkaline media, which could be attributed to the presence of Aux-Agynanoparticles on the electrode surface. The voltammetric results suggest that the glucose oxidation speed is controlled by the glucose diffusion to the electrode surface. These results also show that the catalytic activity of the electrodes depends on the Ag content of the nanoparticles. Best results were obtained for the Au80-Ag20nanoparticles modified electrode. This electrode could be used for Gluconic acid (GA) production.

Electrochemical Characterization of Nickel-Phosphorus Based Coatings Containing Cobalt

2015 ◽  
Vol 228 ◽  
pp. 299-304
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok
Keyword(s):  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Porous Electrode ◽  
Absorption Spectrometry ◽  
X Ray Diffraction ◽  
Morphology Characterization ◽  
Galvanostatic Conditions ◽  
Matrix Powder ◽  
Xrd Method

The Ni-P, Ni-Co-P and Ni-P+Co coatings were obtained in galvanostatic conditions at the current density ofjdep= -200 mA cm-2. A stereoscopic microscope was used for surface morphology characterization of the coatings. The X-ray diffraction (XRD) method was used to determine phase composition of the coatings and the atomic absorption spectrometry (AAS) was applied to specify their chemical composition. The behavior of the obtained coatings was investigated in the process of hydrogen evolution reaction (HER) from 5 M KOH using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. It was found that introduction into Ni-P amorphous matrix powder of cobalt produced porous electrode materials which could be used for the HER.

Synthesis and Characterization of Li0.97K0.03FePO4/Graphene Composites by Carbonthermal Reduction Method

2014 ◽  
Vol 687-691 ◽  
pp. 4327-4330
Author(s):  
Yan Wang ◽  
Zhe Sheng Feng ◽  
Lu Lin Wang ◽  
Jin Ju Chen ◽  
Zhen Yu He
Keyword(s):  
Discharge Capacity ◽  
Photoelectron Spectroscopy ◽  
Reduction Method ◽  
Electrochemical Impedance ◽  
Impedance Spectra ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Electrochemical Impedance Spectra ◽  
X Ray

Li0.97K0.03FePO4 and Li0.97K0.03FePO4/graphene composites were synthesized by carbothermal reduction method using acetylene black as carbon source. The structure and electrochemical properties of the prepared materials were investigated with X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, galvanostatic charge and discharge and electrochemical impedance spectra tests. The results indicated that K doping improves the cyclic stability of samples, the addition of small amounts of graphene results in better electronic properties on sample. Li0.97K0.03FePO4/graphene showed discharge capacity of 158.06 and 90.55 mAh g-1 at 0.1 C and 10 C, respectively. After the 50 cycle test at different rates, the reversible discharge capacity at 0.1 C was 158.58 mAh g-1, indicating the capacity retention ratio of 100.32%.

scholarly journals Electrochemical and electron microscopic characterization of Super-P based cathodes for Li–O2 batteries

2013 ◽  
Vol 4 ◽  
pp. 665-670 ◽  
Author(s):  
Mario Marinaro ◽  
Santhana K Eswara Moorthy ◽  
Jörg Bernhard ◽  
Ludwig Jörissen ◽  
Margret Wohlfahrt-Mehrens ◽  
...  
Keyword(s):  
Lithium Salt ◽  
Electrochemical Impedance ◽  
Ex Situ ◽  
Cathode Side ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Li Ion

Aprotic rechargeable Li–O2 batteries are currently receiving considerable interest because they can possibly offer significantly higher energy densities than conventional Li-ion batteries. The electrochemical behavior of Li–O2 batteries containing bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode side during the operation of Li–O2 cells.

Optimizing Performance of ZnO Nanorod and Activated Carbon as a Composite Anode for Lithium-Ion Batteries

2020 ◽  
Vol 1000 ◽  
pp. 31-40
Author(s):  
Bambang Priyono ◽  
Ananta Riezky Bachtiar ◽  
Hugo Abraham ◽  
Mohammad Ridho Nugraha ◽  
Faizah ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electrochemical Impedance ◽  
Zno Nanorods ◽  
Specific Capacity ◽  
Lithium Ion ◽  
High Porosity ◽  
Composite Anode ◽  
X Ray Diffraction ◽  
Stable Performance

To obtain the high specific capacity anode for Lithium-ion battery with stable performance is conducted by synthesizing a composite anode of ZnO-nanorods (ZnO-NR) and as a matrix is the activated carbon (AC). In this study, ZnO-NR synthesized a process that uses basic materials hexamethylenetetramine (HMTA) and zinc oxide. Activated carbon has been activated because it has high porosity and good electrical conductivity properties. Variable used is the percentage of ZnO-NR, which is 30wt%, 40wt%, and 50wt%. Characterization of the samples was examined using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Brunauer–Emmett–Teller (BET). The battery performance of the samples was obtained by Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), and Charge-Discharge (CD) testing after being assembled into coin cell batteries. This study discusses the effect of adding activated carbon to ZnO NR composites. The results showed that the ZnO-NR30/AC has the highest specific capacity of 270.9 mAh g-1. According to Brunner-Emmet-Teller (BET) test, the largest surface area was 631.685 m2 g-1. Electrochemical performance is the best obtained by ZnO-NR30/AC.

Characterization of mediated and non-mediated oxidase enzyme based glassy carbon electrodes

Talanta ◽  
1993 ◽  
Vol 40 (8) ◽  
pp. 1157-1162 ◽  
Author(s):  
A. Amine ◽  
J.-M. Kauffmann ◽  
G.J. Patriarche ◽  
G.D. Christian
Keyword(s):  
Glassy Carbon ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Oxidase Enzyme

scholarly journals Electrochemical and Morphological Investigations of Ga Addition to Pt Electrocatalyst Supported on Carbon

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Giordano T. Paganoto ◽  
Deise M. Santos ◽  
Tereza C. S. Evangelista ◽  
Marco C. C. Guimarães ◽  
Maria Tereza W. D. Carneiro ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Physicochemical Characterization ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered

This paper is consisted in the synthesis of platinum-based electrocatalysts supported on carbon (Vulcan XC-72) and investigation of the addition of gallium in their physicochemical and electrochemical properties toward ethanol oxidation reaction (EOR). PtGa/C electrocatalysts were prepared through thermal decomposition of polymeric precursor method at a temperature of 350°C. Six different compositions were homemade: Pt50Ga50/C, Pt60Ga40/C, Pt70Ga30/C, Pt80Ga20/C, Pt90Ga10/C, and Pt100/C. These electrocatalysts were electrochemically characterized by cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) in the presence and absence of ethanol 1.0 mol L−1. Thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were also carried out for a physicochemical characterization of those materials. XRD results showed the main peaks of face-centered cubic Pt. The particle sizes obtained from XRD and TEM analysis range from 7.2 nm to 12.9 nm. The CV results indicate behavior typical of Pt-based electrocatalysts in acid medium. The CV, EIS, and CA data reveal that the addition of up to 31% of gallium to the Pt highly improves catalytic activity on EOR response when compared to Pt100/C.

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