scholarly journals Electrocoagulation of whey acids: anode and cathode materials, electroactive area and polarization curves

2017 ◽  
Vol 7 (2) ◽  
pp. 89
Author(s):  
Francisco Prieto Garcia ◽  
Judith Callejas Hernandez ◽  
Judith Prieto Mendez ◽  
Yolanda Marmolejo Santillan
Keyword(s):  
Cyclic Voltammetry ◽  
Charge Transfer ◽  
Double Layer ◽  
Cathode Materials ◽  
Time Correlation ◽  
Polarization Curves ◽  
Double Layer Capacitance ◽  
Cathodic Materials ◽  
Capacitance Method ◽  
Acid Whey

<p><span lang="EN-US">Anode (Al and Fe) and cathode (graphite and Ti/RuO<sub>2</sub>) materials have been tested for electrocoagulation (EC) and purification of the acid whey. The electroactive areas (EA) of electrodes were calculated by the double layer capacitance method. Experiments were performed by cyclic voltammetry, chronoamperometry and polarization experiments. Among cathodic materials, the Ti/RuO<sub>2</sub> electrode showed higher EA (2167 cm<sup>2</sup>) than graphite (1560 cm<sup>2</sup>). The Fe anode was found more stable than Al with greater charge transfer carried out in less time. Correlation of these results with those obtained during preliminary tests confirmed high removals (79 %) in 8 h. For the Al electrode, 24 h were required to achieve efficiency of 49 %.</span></p>

scholarly journals Seven Steps to Reliable Cyclic Voltammetry Measurements for the Determination of Double Layer Capacitance

2021 ◽  
Author(s):  
Dulce M. Morales ◽  
Marcel Risch
Keyword(s):  
Cyclic Voltammetry ◽  
Double Layer ◽  
High Performance ◽  
Electric Circuit ◽  
Precise Determination ◽  
Intrinsic Activity ◽  
Suitable Model ◽  
Double Layer Capacitance ◽  
Step Method

Discovery of electrocatalytic materials for high-performance energy conversion and storage applications relies on the adequate characterization of their intrinsic activity, which is currently hindered by the dearth of a protocol for consistent and precise determination of double layer capacitance (C<sub>DL</sub>). Herein, we propose a seven-step method that aims to determine C<sub>DL</sub> reliably by scan rate-dependent cyclic voltammetry. The method considers three aspects that strongly influence the outcome of the analysis: measurement settings, data collection, and data processing. To illustrate the proposed method, two systems were studied: a resistor-capacitor electric circuit and a glassy carbon disk in an electrochemical cell. With these studies it is demonstrated that when any of the mentioned aspects of the procedure are neglected, substantial deviations of the results are observed with misestimations as large as 61% in the case of the investigated electrochemical system. Moreover, we propose allometric regression as a more suitable model than linear regression for the determination of C<sub>DL</sub> for both the ideal and the non-ideal systems investigated. We stress the importance of assessing the accuracy of not only highly specialized electrochemical methods, but also of those that are well-known and commonly used as it is the case of the voltammetric methods. The methodology proposed herein is not limited to the determination of C<sub>DL</sub>, but can be effectively applied to any other voltammetry-based analysis that aims to deliver quantitative results.

scholarly journals Influence of digene tablet juice orally taken in on the corrosion resistance of orthodontic wire made of SS 18/8 in presence of artificial saliva

2021 ◽  
Vol 62 (3) ◽  
pp. 220-227
Author(s):  
Chandrasekaran Priya ◽  
Antony Regis ◽  
Susai Rajendran
Keyword(s):  
Corrosion Resistance ◽  
Charge Transfer ◽  
Double Layer ◽  
Artificial Saliva ◽  
Corrosion Current ◽  
Charge Transfer Resistance ◽  
Double Layer Capacitance ◽  
Orthodontic Wires ◽  
Transfer Resistance ◽  
Orthodontic Wire

Dentists make use of orthodontic wires such as SS 18/8, SS 316, Ni-Cr etc., to regulate the growth of teeth. In the saliva environment these wires undergo corrosion. Aside from this, they undergo corrosion by the food items, juices and Tablets orally in taken. Corrosion resistance of SS 18/8 alloy in artificial saliva (AS) , in the absence and presence of Digene Tablet juice, has been investigated by polarization and AC impendance techniques. It is inferred that corrosion resistance of SS 18/8 alloy in artificial saliva decreases in presence of Digene Tablet. This is exposed by decrease in Linear Polarization Resistance (LPR) value, Charge transfer resistance (Rt) value, in impedance value, and increase in corrosion current and double layer capacitance value(Cdl). In presence of Digene Tablet, the LPR value decreases from 3488228 to 1629535 Ohmcm2. The corrosion current value increases from 1.447 x10-8 to 2.637x10-8A/cm2 . The Charge transfer resistance (Rt) value decreases from 37796 to 10481Ohmcm2 . The double layer capacitance value increases from 1.349x10-10 F/cm2 to 4.866x10-10F/cm2. The impedance value decreases from 4.857 to 4.428. Hence it implies that people with orthodontic wire made of SS 18/8 alloy should avoid taking Digene Tablet juice orally.

scholarly journals Seven Steps to Reliable Cyclic Voltammetry Measurements for the Determination of Double Layer Capacitance

2020 ◽  
Author(s):  
Dulce M. Morales ◽  
Marcel Risch
Keyword(s):  
Cyclic Voltammetry ◽  
Double Layer ◽  
High Performance ◽  
Electric Circuit ◽  
Precise Determination ◽  
Intrinsic Activity ◽  
Suitable Model ◽  
Double Layer Capacitance ◽  
Step Method

Discovery of electrocatalytic materials for high-performance energy conversion and storage applications relies on the adequate characterization of their intrinsic activity, which is currently hindered by the dearth of a protocol for consistent and precise determination of double layer capacitance (C<sub>DL</sub>). Herein, we propose a seven-step method that aims to determine C<sub>DL</sub> reliably by scan rate-dependent cyclic voltammetry. The method considers three aspects that strongly influence the outcome of the analysis: measurement settings, data collection, and data processing. To illustrate the proposed method, two systems were studied: a resistor-capacitor electric circuit and a glassy carbon disk in an electrochemical cell. With these studies it is demonstrated that when any of the mentioned aspects of the procedure are neglected, substantial deviations of the results are observed with misestimations as large as 61% in the case of the investigated electrochemical system. Moreover, we propose allometric regression as a more suitable model than linear regression for the determination of C<sub>DL</sub> for both the ideal and the non-ideal systems investigated. We stress the importance of assessing the accuracy of not only highly specialized electrochemical methods, but also of those that are well-known and commonly used as it is the case of the voltammetric methods. The methodology proposed herein is not limited to the determination of C<sub>DL</sub>, but can be effectively applied to any other voltammetry-based analysis that aims to deliver quantitative results.

scholarly journals Seven Steps to Reliable Cyclic Voltammetry Measurements for the Determination of Double Layer Capacitance

2020 ◽  
Author(s):  
Dulce M. Morales ◽  
Marcel Risch
Keyword(s):  
Cyclic Voltammetry ◽  
Double Layer ◽  
High Performance ◽  
Electric Circuit ◽  
Precise Determination ◽  
Intrinsic Activity ◽  
Suitable Model ◽  
Double Layer Capacitance ◽  
Step Method

Discovery of electrocatalytic materials for high-performance energy conversion and storage applications relies on the adequate characterization of their intrinsic activity, which is currently hindered by the dearth of a protocol for consistent and precise determination of double layer capacitance (C<sub>DL</sub>). Herein, we propose a seven-step method that aims to determine C<sub>DL</sub> reliably by scan rate-dependent cyclic voltammetry. The method considers three aspects that strongly influence the outcome of the analysis: measurement settings, data collection, and data processing. To illustrate the proposed method, two systems were studied: a resistor-capacitor electric circuit and a glassy carbon disk in an electrochemical cell. With these studies it is demonstrated that when any of the mentioned aspects of the procedure are neglected, substantial deviations of the results are observed with misestimations as large as 61% in the case of the investigated electrochemical system. Moreover, we propose allometric regression as a more suitable model than linear regression for the determination of C<sub>DL</sub> for both the ideal and the non-ideal systems investigated. We stress the importance of assessing the accuracy of not only highly specialized electrochemical methods, but also of those that are well-known and commonly used as it is the case of the voltammetric methods. The methodology proposed herein is not limited to the determination of C<sub>DL</sub>, but can be effectively applied to any other voltammetry-based analysis that aims to deliver quantitative results.

scholarly journals Decrease in the double layer capacitance by faradaic current

RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22501-22509 ◽  
Author(s):  
Koichi Jeremiah Aoki ◽  
Jingyuan Chen ◽  
Xiangdong Zeng ◽  
Zhaohao Wang
Keyword(s):  
Charge Transfer ◽  
Double Layer ◽  
Double Layer Capacitance ◽  
Faradaic Current ◽  
The Relationship

This study describes the reverse of the well-known double layer effects on charge transfer kinetics in the relationship between a cause and an effect.

The Extraction of Double-Layer Capacitance: In a Case of PANI Film

2019 ◽  
Vol 17 (3) ◽  
Author(s):  
Xiangdong Zeng ◽  
Kun Zhou ◽  
Shijie Xian ◽  
Linting Jiang
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Double Layer ◽  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Diffusion Control ◽  
Pani Film ◽  
Double Layer Capacitance ◽  
Frequency Dependent ◽  
Dc Potential

Abstract The extraction of double-layer capacitance (DLC) is proposed using the electrochemical impedance spectroscopy (EIS) technique. By the concept of the frequency-dependent DLC, the DLC of polyaniline (PANI)-coated platinum wire is separated from the total capacitance at different DC potentials. The high conducting oxidized PANI is less frequency dependent. The DLC at the frequency of 1 Hz is the same as that of separation from the faradic current by cyclic voltammetry technology, exhibiting S-shaped curve at different DC potential. The process of the oxidation of PANI during the electrochemical impedance measurement is similar to the diffusion control.

scholarly journals Parallel 1024-ch Cyclic Voltammetry on Monolithic CMOS Electrochemical Detector Array

2019 ◽  
Author(s):  
Kevin A. White ◽  
Geoffrey Mulberry ◽  
Brian N. Kim
Keyword(s):  
Cyclic Voltammetry ◽  
Double Layer ◽  
Electrode Array ◽  
Effective Area ◽  
Electrochemical Measurements ◽  
Detector Array ◽  
Double Layer Capacitance ◽  
Electrochemical Detector ◽  
Electrochemical Electrodes ◽  
On Chip

AbstractLarge-scale microelectrode arrays offers enhanced spatiotemporal resolution in electrophysiology studies.. In this paper, we discuss the design and performance of an electrochemical detector array which is capable of 1024-ch parallel cyclic voltammetry (CV) as well as other electrochemical measurements. The electrochemical detector is fabricated using a custom-designed CMOS chip which integrates both the circuity and on-chip microelectrode array, to operate and record from electrochemical measurements. For parallel 1024-ch recordings, 1024 capacitor-based integrating transimpedance amplifiers (TIA) are designed and integrated. The TIA design features the bipolar capabilities for measuring both negative and positive electrochemical currents due to reduction and oxidation of molecules. The resulted dynamic range of this TIA is −700 pA – 1968 pA. CV can be used to examine the quality of electrochemical electrodes by measuring the double-layer capacitance. Double-layer capacitance forms at the electrode-electrolyte interface and is a function of the effective area of the electrode. Thus, a contaminated electrode can have smaller effective area resulting in smaller double-layer capacitance. Using the parallel CV capability of the monolithic CMOS device, the double layer capacitance of all 1024 electrodes are simultaneously measured to examine the status of the electrodes’ surface in real time. The initial measurement of the electrode array showed a mean capacitance of 466 pF. After plasma treatment to remove contamination on the electrode’s surface, the increased capacitance was 1.36nF nearly tripling the effective surface area. We have successfully developed of 1024-ch electrochemical detector array using the monolithic CMOS sensor. The CV functionality was validated by measuring the double-layer capacitance of the on-chip electrode array. This method can accelerate the characterization of a massive electrode array before analytical experiments to provide well-controlled electrochemical electrodes, which is crucial in conducting reliable electrochemical measurements.

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