Electrochemical Oxidation of Borohydride on Cu Electrode

2011 ◽  
Vol 347-353 ◽  
pp. 3264-3267 ◽  
Author(s):  
Dong Hong Duan ◽  
Yi Fang Zhao ◽  
Shi Bin Liu ◽  
Ai Lian Wu
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Electrochemical Behavior ◽  
Intermediate Product ◽  
Electrode Materials ◽  
Oxidation Process ◽  
Potential Range ◽  
Direct Oxidation ◽  
Catalytic Activities ◽  
Electro Oxidation

The electrochemical behavior of BH4- on Cu electrode in 1M NaOH was investigated by cyclic voltammetry(CV) in the potential range of -1.2V to 0.4V versus Hg/HgO. The CV results show that Cu electrode has obvious catalytic activities to the BH4- hydrolysis which belongs to ‘catalytic’ electrode materials. The BH4- electro-oxidation process on Cu is complex and it could associate with the BH4- hydrolysis reaction, followed by oxidation of the intermediate H, then, the intermediate product (e.g. BH3OH−) oxidized, and direct oxidation of BH4- at more positive potentials.

Enhanced Electrochemical Oxidation of BH4− on Pt Electrode in Alkaline Electrolyte with the Addition of Thiourea

2010 ◽  
Vol 132 ◽  
pp. 271-278 ◽  
Author(s):  
Dan Mei Yu ◽  
Chang Guo Chen ◽  
Shu Lei ◽  
Xiao Yuan Zhou ◽  
Guo Zhong Cao
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Electrochemical Impedance ◽  
Alkaline Electrolyte ◽  
Hydroxyl Groups ◽  
Catalytic Hydrolysis ◽  
Direct Oxidation ◽  
Pt Electrode ◽  
Separation Membrane ◽  
And Diffusion

The electrochemical oxidation of sodium borohydride (NaBH4) on Pt electrode in alkaline electrolyte with the addition of thiourea has been studied by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry (CP). NaBH4 is readily to react with hydroxyl groups to release hydrogen through either direct oxidation or catalytic hydrolysis. The experimental results demonstrated that the addition of an appropriate amount of thiourea to the alkaline electrolyte resulted in the suppression of catalytic hydrolysis and diffusion of borohydride ions through the separation membrane.

Electrochemical Reaction Mechanism of Tiron in Acidic Aqueous Solution

2011 ◽  
Vol 396-398 ◽  
pp. 1730-1735 ◽  
Author(s):  
Yan Xu ◽  
Yue Hua Wen ◽  
Jie Cheng ◽  
Gao Ping Cao ◽  
Yu Sheng Yang
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Aqueous Solutions ◽  
Electrochemical Oxidation ◽  
Electrochemical Reaction ◽  
Mass Spectrometric ◽  
Acidic Aqueous Solution ◽  
Ece Mechanism ◽  
Flow Through ◽  
Electro Oxidation

Electrochemical oxidation of tiron in the presence of H2O as a nucleophile in strongly acidic aqueous solutions was studied by cyclic voltammetry, controlled-voltage coulometry and spectrometric investigations. The mechanism of electrochemical reaction is confirmed by spectrophotometric tracing in various times of controlled-voltage coulometry. The voltammetric and spectrophotometric foundations indicate that a 1,4-Michael addition of H2O from its hydroxy moiety to the position 4 of electrochemically derived o-quinone is occurred. The electrochemical oxidation and reduction of tiron has been successfully accomplished by controlled-voltage coulometry in a redox flow-through type cell and the final electro-reduced product was characterized by spectrophotometric, 1H NMR and mass spectrometric methods. It is demonstrated that the electro-oxidation of tiron follows an ECE mechanism in acidic aqueous solutions, leading to formation of a new compound of para- benzoquinone derivative.

Determination of HOMO and LUMO Level of Polythiophene, Poly(3-Thiophene Acetic Acid), Polypyrrole and Chlorophyll via Cyclic Voltammetry Method

2020 ◽  
Vol 307 ◽  
pp. 207-216
Author(s):  
Hasiah Salleh ◽  
Nora'aini Ali ◽  
Chi Chin Yap ◽  
Azhar Mohd Sinin ◽  
Nurhayati Ishak ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Acetic Acid ◽  
Indium Tin Oxide ◽  
Electrochemical Behavior ◽  
Oxidation Process ◽  
Chemical Reactivity ◽  
Energy Levels ◽  
Molecular Ions ◽  
Level Energy ◽  
Cyclic Voltammetry Method

Cyclic voltammetry can be used to investigate the chemical reactivity of species ion via oxidation and reduction process. The purpose of this study is to determine the level energy of high occupied molecule orbital (HOMO) and low unoccupied molecule orbital (LUMO) in polythiophene (PT), Poly (3-thiophene acetic acid) (P3TAA), polypyrrole (PPY) and chlorophyll (Chlo) through oxidation and reduction of molecular ions by cyclic voltammetry method. PT, P3TAA, PPY and Chlo solutions were prepared in a solvent of acetonitrile at the concentration range of 10-2 to 10-4 M. The current-voltage measurements for these solutions are performed using cyclic voltammetry method on input voltage from -2.0 V to 2.0 V. The working electrode used is indium tin oxide (ITO). The result of voltammogram is showed that the activity of PT species were produced three oxidation and one reduction processes. The formal reduction potential, Eo¢ is 0.83 (positive) meaning that oxidation process was dominant. So that the reaction of PT species was exhibited irreversible electrochemical behavior. The reaction of P3TAA species was exhibited reversible electrochemical behavior, where the range value of oxidation, DEpa and reduction, DEpc were in range of 0.825 V to 1.120 V and -0.230 V to 0.131 V respectively. PYY species reaction was exhibited irreversible electrochemical behavior where two oxidation states occur within -0.145 V to -0.202 V and 0.870 V to 1.63 V respectively. The species activity of Chlo was exhibited irreversible electrochemical behavior where only the oxidation process was obviously appeared at range of 0.80 V to 0.95 V. The LUMO energy levels of PT, P3TAA PPY and Chlo were 5.84 eV, 5.34 eV, 1.10 eV and 3.85 eV respectively, while HOMO energy levels of PT, P3TAA PPY and Chlo were 4.61 eV, 4.25eV, 3.70 eV and 5.93 eV. The average value of energy gap of PT, P3TAA, PPY and Chlo were 1.23 eV, 1.08 eV, 2.23 eV and 1.10 eV respectively.

Selenium(IV) Electrochemistry on Silver: A Combined Electrochemical Quartz-Crystal Microbalance and Cyclic Voltammetric Investigation

2003 ◽  
Vol 68 (9) ◽  
pp. 1579-1595 ◽  
Author(s):  
Giovanni Pezzatini ◽  
Francesca Loglio ◽  
Massimo Innocenti ◽  
Maria Luisa Foresti
Keyword(s):  
Cyclic Voltammetry ◽  
Quartz Crystal Microbalance ◽  
Electrochemical Behavior ◽  
Quartz Crystal ◽  
Reduction Process ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Potential Range ◽  
Cyclic Voltammetric ◽  
Scan Rate ◽  
Process Of Se

The electrochemical behavior of Se(IV) on silver was investigated by cyclic voltammetry and electrochemical quartz-crystal microbalance (EQCM) measurements. As already reported in the literature, Se(IV) electrochemistry is always complex, and on silver even more, due to the formation of a compound. Our results confirm that the reduction process of Se(IV) occurs through two reaction paths, Se(IV) → Se(0) and Se(IV) → Se(-II); the product Se(-II) then reacts with Se(IV) through a comproportionation reaction. The latter step leads to red Se that, according to the literature, is the only electroactive form of Se(0). The presence of the electroactive red Se is evident both in the negative range of potentials, through the reduction Se(0) → Se(-II), and in the less negative range of potentials, through the oxidation Se(0) → Se(IV). Moreover, our measurements pointed to the formation of a deposit that never redissolves. This deposit seems to be the electroinactive gray Se. The electrochemical behavior of Se(IV) was investigated in the whole potential range accessible on silver. Our results confirm the occurrence of competitive processes whose predominance depends on the scan rate, as well as on the potential limits of voltammetry. A detailed table with the processes occurring in different potential ranges was drawn up.

scholarly journals Pencil graphite as electrode platform for free chlorine sensors and energy storage devices

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248142
Author(s):  
Jahidul Islam ◽  
Han Shao ◽  
Md. Mizanur Rahman Badal ◽  
Kafil M. Razeeb ◽  
Mamun Jamal
Keyword(s):  
Energy Storage ◽  
Density Functional ◽  
Electrode Materials ◽  
Oxidation Process ◽  
Low Cost ◽  
Residual Chlorine ◽  
Cyclic Voltammogram ◽  
Electro Oxidation ◽  
Energy Storage Applications ◽  
Free Residual Chlorine

Multifunctional and low-cost electrode materials are desirable for the next-generation sensors and energy storage applications. This paper reports the use of pencil graphite as an electrode for dual applications that include the detection of free residual chlorine using electro-oxidation process and as an electrochemical energy storage cathode. The pencil graphite is transferred to cellulose paper by drawing ten times and applied for the detection of free residual chlorine, which shows a sensitivity of 27 μA mM-1 cm-2 with a limit of detection of 88.9 μM and linearity up to 7 mM. The sample matrix effect study for the commonly interfering ions such as NO3-, SO42-, CO32-, Cl-, HCO3- shows minimal impact on free residual chlorine detection. Pencil graphite then used after cyclic voltammogram treatment as a cathode in the aqueous Zn/Al-ion battery, showing an average discharge potential plateau of ~1.1 V, with a specific cathode capacity of ~54.1 mAh g-1 at a current of 55 mA g-1. It maintains ~95.8% of its initial efficiency after 100 cycles. Results obtained from the density functional theory calculation is consistent with the electro-oxidation process involved in the detection of free residual chlorine, as well as intercalation and de-intercalation behavior of Al3+ into the graphite layers of Zn/Al-ion battery. Therefore, pencil graphite due to its excellent electro-oxidation and conducting properties, can be successfully implemented as low cost, disposable and green material for both sensor and energy-storage applications.

scholarly journals STUDY ON ELECTRO-OXIDATION OF GLYCEROL IN ALKALINE MEDIUM USING TRIMETALLIC Pt-Pd-Ni COMPOSITE ELECTRODEPREPARED ON GLASSY CARBON

2018 ◽  
Vol 55 (5B) ◽  
pp. 126
Author(s):  
Huynh Thi Lan Phuong
Keyword(s):  
Activation Energy ◽  
Cyclic Voltammetry ◽  
Reaction Mechanism ◽  
Glassy Carbon ◽  
Oxidation Process ◽  
Diffusion Mechanism ◽  
Effect Of Temperature ◽  
First Order ◽  
Trimetallic Catalyst ◽  
Electro Oxidation

In this research, the effect of temperature and conversion of glycerol was studied by using cyclic voltammetry technique. The results showed that this reaction occurred following to diffusion mechanism with activation energy approximately of 3.44 (kcal/mol). Moreover, conversion of glycerol by electrolysis using Pt-Pd-Ni/C catalyst also was investigated and compared with the case of using pure Pt. Electrolysis process with electrode Pt-Pd-Ni/GC and pure Pt-was occurred by the first order and this result was well-suit with the previous study about the reaction mechanism of glycerol electro-oxidation process. Obtained results showed that conversion of glycerol on the trimetallic catalyst was higher than the pure Pt.

Electrochemical Response of Gold Nanoparticles at a Graphite Electrode

2014 ◽  
Vol 1040 ◽  
pp. 297-302 ◽  
Author(s):  
D.O. Perevezentseva ◽  
E.V. Gorchakov
Keyword(s):  
Gold Nanoparticles ◽  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Phase Structure ◽  
Graphite Electrode ◽  
Supporting Electrolyte ◽  
Potential Range ◽  
Cyclic Voltammogram ◽  
Cathodic Peak ◽  
Graphite Electrodes

The electrochemical activity of gold nanoparticles at graphite electrodes by the method of cyclic voltammetry is studied. In this article the nature of the supporting electrolyte, modification time of graphite electrode by gold nanoparticles and the potential range on the value of the “inverse” cathodic peak are investigated. The “inverse” cathodic peak of gold nanoparticles formed in the reaction mixture HAuCl4:Na3C6H5O7:NaBH4=1:1:4 is observed on the cathodic branch of cyclic voltamperegram at Ec = 0.05 V at graphite electrode. The mechanism of stepwise electrochemical oxidation and reduction of the phase structure of gold on the surface of the graphite electrode in 0.1 M NaOH is offered. The “inverse” cathodic peak of gold nanoparticles on the cathodic branch of cyclic voltammogram at graphite electrode is caused by oxidation of Au2O to Au2O3.<br /><br />

scholarly journals Application of Taguchi’s experimental design method for optimization of Acid Red 18 removal by electrochemical oxidation process

2018 ◽  
Vol 5 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Zabihollah Yousefi ◽  
Ali Zafarzadeh ◽  
Abdolaziz Ghezel
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Oxidation Process ◽  
Design Method ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Fractional Factorial ◽  
Synthetic Wastewater ◽  
Electro Oxidation ◽  
Electro Coagulation

Background: Electro-oxidation is developed as an electrochemical method to overcome the problems of the conventional decolorization technologies and is an appropriate alternative for the treatment of colored wastewater from various industries. The purpose of this study was to evaluate the efficiency of the electrochemical oxidation process in removal of chemical oxygen demand (COD) and Acid Red 18 (AR18) dye from aqueous solutions. Methods: In this research, a laboratory scale of electro-coagulation reactor for the treatment of synthetic wastewater was made and studied. The effects of different variables including pH, current density, dye concentration, and electrolysis time were investigated. The experiment steps were designed by DesignExpert 10 software using the selected variables. Finally, the dye and COD analysis was performed by spectrophotometer. The optimization was performed using Taguchi fractional factorial design during the removal of dye and COD. Results: Maximum removal of dye (89%) and COD (72.2%) were obtained at pH=3, current density=20 mA/cm2 , initial dye concentration=100 mg/L, and reaction time=45 min. ANOVA test showed a significant relationship between statistical model and test data. Also, the results indicate that the distribution of the residues of the model was normal. Conclusion: By designing experiments through Taguchi method, the removal process will be optimized and by decreasing the number of experiments, the optimal conditions for pollutant removal will be prepared. The results suggest that the Electro-oxidation system is a very suitable technique for the enhancement of wastewater treatment.

Electrochemical behavior of amidine hydrochlorides and amidines

1995 ◽  
Vol 73 (3) ◽  
pp. 362-374 ◽  
Author(s):  
Benoit Daoust ◽  
Jean Lessard
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Electrochemical Behavior ◽  
Platinum Electrode ◽  
Chloride Anion ◽  
Vitreous Carbon ◽  
Reduction Peak ◽  
Oxidation Peak ◽  
Preparative Electrolysis ◽  
Discharge Potential

The electrochemical behavior of N,N-dimethyl-N′-phenylformamidine hydrochloride was studied on a platinum electrode. The oxidation peak at +0.90 V vs. Ag/Ag+ 0.01 M (in CH3CN −0.1 M LiClO4) was assigned to the oxidation of the chloride anion. N,N-Dimethyl-N′-(4-chlorophenyl)formamidine and N,N-dimethyl-N′-(2-chlorophenyl)formamidine were isolated from the preparative electrolysis of this amidine hydrochloride. The electrochemical behavior of N-phenylbenzamidine hydrochloride and N-phenylcyclohex-3-enecarboxamidine hydrochloride was also studied at platinum and at vitreous carbon. Cyclic voltammetry of a number of amidines was performed. Only N-arylbenzamidines showed a reduction peak at potentials less negative than −3.0 V vs. Ag/Ag+ 0.01 M (discharge potential of the medium at vitreous carbon). Preparative electrooxidations of all amidines studied were unsuccessful because of strong and rapid passivation of the anode. Keywords: amidine, electrochemical oxidation, chloride, amidine hydrochloride.

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