A study of the electro-catalytic oxidation of methanol on a cobalt hydroxide modified glassy carbon electrode

Jafarian, M.; Mahjani, M.G.; Heli, H.; Gobal, F.; Khajehsharifi, Habibollah; Hamedi, Mohammad-Hossein

doi:10.1016/s0013-4686(03)00399-2

Cited by 165 publications

(75 citation statements)

References 18 publications

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“…The voltammograms are similar to those reported in literature. 35,36 Figure 1B shows a cyclic voltammogram of CHM-GC electrode in 100 mmol L -1 NaOH solution in the range of −200 to 690 mV recorded at a potential sweep rate of 100 mV s -1 . It shows anodic peaks located at 225 and 550 mV/SCE which are attributed to Co(II)/Co(III) and Co(III)/Co(IV) redox transitions associated with different cobalt oxide species on the electrode surface.…”

Section: Resultsmentioning

confidence: 99%

Kinetic study of electrocatalytic oxidation of carbohydrates on cobalt hydroxide modified glassy carbon electrode

Karim‐Nezhad

Hasanzadeh

Saghatforoush

et al. 2009

J. Braz. Chem. Soc.

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Este estudo investigou a oxidação eletrocatalítica de frutose, sacarose, glucose, lactose, arabinose e maltose em nanopartículas de hidróxido de cobalto eletrodepositadas na superfície de eletrodo de carbono vítreo em soluções alcalinas. Voltametria cíclica (VC), cronoamperometria (CA) e também medidas de polarização de estado estacionário foram empregados. Nos estudos de VC, na presença de carboidrato, o aumento na corrente de pico da oxidação do hidróxido de cobalto é seguido pelo decréscimo na correspondente corrente catódica. Isto indica que os carboidratos foram oxidados pelo mediador redox, o qual foi imobilizado na superfície do eletrodo, via um mecanismo eletrocatalítico. Com o uso da equação de Laviron, os valores dos coeficientes de transferência de elétron, anódicos e catódicos, e a constante da razão de transferência de carga para as espécies redox imobilizadas foram determinadas como 0,71 ± 0,03, 0,33 ± 0,03 e 0,21 ± 0,02 s This study investigated the electrocatalytic oxidation of fructose, sucrose, glucose, lactose, arabinose and maltose on nanoparticles of cobalt hydroxide electrodeposited on the surface of glassy carbon electrode in alkaline solutions. Cyclic voltammetry (CV), chronoamperometry (CA) techniques and also steady state polarization measurements have been employed. In CV studies, in the presence of carbohydrate the increase of the peak current of the oxidation of cobalt hydroxide is followed by a decrease in the corresponding cathodic current. This indicates that carbohydrates were oxidized by the redox mediator which was immobilized on the electrode surface via an electrocatalytic mechanism. With the use of Laviron's equation, the values of anodic and cathodic electron-transfer coefficients and charge transfer rate constant for the immobilized redox species were determinated as 0.71 ± 0.03, 0.33 ± 0.03 and 0.21 ± 0.02 s -1 , respectively. The rate constant, the electron transfer coefficient and the diffusion coefficients involved in the electrocatalytic oxidation of carbohydrates were determined.

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Section: Resultsmentioning

confidence: 99%

Kinetic study of electrocatalytic oxidation of carbohydrates on cobalt hydroxide modified glassy carbon electrode

Karim‐Nezhad

Hasanzadeh

Saghatforoush

et al. 2009

J. Braz. Chem. Soc.

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“…The voltammograms are similar to those reported in literature. 10,11 Figure 1B shows a cyclic voltammogram of CHM-GC electrode in 100 mM NaOH solution in the range of -200 to 690 mV recorded at a potential sweep rate of 100 mV s ) and the proportionality of anodic (b') and cathodic (c') peak currents to the square roots of sweep rate at higher values (100-900 mV s To investigate the surface morphology of the cobalt hydroxide film formed on the GC surface, it was examined by scanning electron microscopy. The results show that considerable amounts of cobalt hydroxide nanoparticles with an average size of 100 nm were formed on the surface of GC electrode.…”

Section: Resultsmentioning

confidence: 99%

“…4,5 Various methods of preparation, ranging from spray pyrolysis, 6 sonication, 7 and sputtering 8 to electrodeposition from aqueous solutions containing complexing agents with various pH values; have been considered. [9][10][11] Meanwhile, little attention has been paid to the electrocatalytic activities of cobalt hydroxide (oxide) modified electrodes in the electrooxidation of drugs.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Study of the Electrooxidation of Mefenamic Acid and Indomethacin Catalysed on Cobalt Hydroxide Modified Glassy Carbon Electrode

Saghatforoush¹,

Hasanzadeh²,

Karim‐Nezhad³

et al. 2009

Bulletin of the Korean Chemical Society

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Electrocatalytic oxidation of two anti-inflammatory drugs (Mefenamic acid and Indomethacin) was investigated on a cobalt hydroxide modified glassy carbon (CHM-GC) electrode in alkaline solution. The process of oxidation and its kinetics were established by using cyclic voltammetry and chronoamperometry techniques as well as steady state polarization measurements. Voltammetric studies indicated that in the presence of under study drugs, the anodic peak current of low-valence cobalt species increased, followed by a decrease in the corresponding cathodic current. This result indicates that the drugs were oxidized via cobalt hydroxide species immobilized on the electrode surface via an EĆ mechanism. A mechanism based on the electrochemical generation of Co (IV) active sites and their subsequent consumption by the drugs in question was also investigated. The constants rate of the catalytic oxidation of the drugs and the electron-transfer coefficients reported.

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“…Jafarian et al [20] have reported a good oxidation of methanol at glassy carbon electrodes modified with cobalt hydroxide. Nickel-cobalt hydroxides electrodes can oxidize methane [21] and indirectly chlorophenols [22].…”

Section: -Introductionmentioning

confidence: 99%

ELECTROOXIDATION OF 2,4,6-TRICHLOROPHENOL ON GLASSY CARBON ELECTRODES MODIFIED WITH COMPOSITE Ni(OH)2-Co(OH)2 FILMS

González¹,

Salazar²,

Marco³

et al. 2013

J. Chil. Chem. Soc.

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Glassy carbon electrodes coated with a film of electrodeposited cobalt and nickel hydroxides were prepared in order to determine its activity to the 2,4,6-trichlorophenol (TCP) oxidation. The modified electrodes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy and Scan Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS). The results indicate that both hydroxides are homogeneously distributed in the electrode surface. From the viewpoint of electrochemical oxidation of TCP, the presence of cobalt and nickel hydroxides on the electrode surface (i) promotes a more complete oxidation of TCP and (ii) decreases the fouling of the electrode surface in comparison with GC and GC modified with Ni or Co separately. Keywords:Modified electrodes, (Ni-Co) hydroxides, chlorophenol oxidation e-mail: soledad.ureta@usach.cl 1.-INTRODUCTIONWaste from domestic, agricultural and industrial activities such as cellulose treatment and the manufacturing of plastics, adhesives and petrochemicals may pollute watercourses [1]. The widely used halogenated compounds are not amenable to biological degradation, and can accumulate in living organisms, this being the reason why they are used as wood preservatives, antibacterial agents, fungicides, insecticides and herbicides [2,3].Au and Pt show high catalytic activity for the electrooxidation of chlorophenols (CP) over short times, but they are quickly fouled up by small oligomers, generated by the coupling of two phenoxy radicals or by reaction of a radical with unreacted CP molecules [4,5]. Electrodes modified with redox mediators could increase the activity and specificity for a given reaction and avoid fouling [6]. So, glassy carbon (GC) electrodes modified with Co(II) phthalocyanine (CoPc) show higher currents and less fouling in the oxidation of 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP) in 1 M NaOH [7]. Also Alatorre et al. [8] found that GC electrodes modified with electropolymerized nickel complexes showed less fouling in the oxidation of 4-CP and 4-nitrophenol in 1 M NaOH. Our laboratory has some experience in this field [4,5,9,10,11]. The goal is to decrease the oligomerization rate and to promote full oxidation of the phenolic compound.The redox mediator activity in alkaline media of electrodes modified with Ni(II) compounds is due to the quasi reversible properties of the Ni(III)/Ni(II) process [9,10,11],which may be represented as follows [12]:Actually nickel hydroxide can have more than one stable structure [13,14,15]. Van der Ven et al. [16] reported the formation of two types of nickel hydroxide, α -and β-Ni(OH) 2 , and two kinds of nickel oxyhydroxides, α -and γ-NiOOH, which, due to their different structures and degrees of hydration, have different electrochemical properties.Other hydroxide, Co(OH) 2 , has been widely used as an additive to Ni(OH) 2 in order to improve alkaline secondary batteries [17,18,19], these improvements being attributed to an increase of bot...

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A study of the electro-catalytic oxidation of methanol on a cobalt hydroxide modified glassy carbon electrode

Cited by 165 publications

References 18 publications

Kinetic study of electrocatalytic oxidation of carbohydrates on cobalt hydroxide modified glassy carbon electrode

Kinetic study of electrocatalytic oxidation of carbohydrates on cobalt hydroxide modified glassy carbon electrode

Kinetic Study of the Electrooxidation of Mefenamic Acid and Indomethacin Catalysed on Cobalt Hydroxide Modified Glassy Carbon Electrode

ELECTROOXIDATION OF 2,4,6-TRICHLOROPHENOL ON GLASSY CARBON ELECTRODES MODIFIED WITH COMPOSITE Ni(OH)2-Co(OH)2 FILMS

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