scholarly journals Methanol electrooxidation on PtRu modified zeolite X

2013 ◽  
Vol 45 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Z. Mojovic ◽  
T. Mudrinic ◽  
Abu Rabi-Stankovic ◽  
A. Ivanovic-Sasic ◽  
S. Marinovic ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Cyclic Voltammetry ◽  
Noble Metal ◽  
Metal Clusters ◽  
Supporting Electrolyte ◽  
Solid Support ◽  
Methanol Electrooxidation ◽  
Metal Acetylacetonates ◽  
Zeolite X ◽  
Scan Rate

Zeolite NaX (faujasite type) was used as a support for platinum-ruthenium catalyst. A procedure for thermal decomposition of noble metal acetylacetonates to deposit noble metal clusters on the surface of solid support was adapted by authors to introduce noble metal clusters in zeolite cavities. The effectiveness of this composite material for methanol electrooxidation from alkaline solution was investigated by cyclic voltammetry. The influence of the concentration of supporting electrolyte, scan rate and rotation rate on the reaction of methanol oxidation was investigated. The obtained activity was compared with literature data for similar catalysts.

scholarly journals Electrochemical Oxidation of Paracetamol Mediated byMgB2Microparticles Modified Glassy Carbon Electrode

2011 ◽  
Vol 8 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Mohammed Zidan ◽  
Tan Wee Tee ◽  
A. Halim Abdullah ◽  
Zulkarnain Zainal ◽  
Goh Joo Kheng
Keyword(s):  
Cyclic Voltammetry ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Supporting Electrolyte ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Diffusion Controlled ◽  
Scan Rate ◽  
Degree Of Stability ◽  
A Current

A MgB2microparticles modified glassy carbon electrode (MgB2/GCE) was fabricated by adhering microparticles of MgB2onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, supporting electrolyte, temperature and scan rate. The current enhancement observed in different electrolytic media varied in the following order: KH2PO4> KCl > K2SO4> KBr. Interestingly, the oxidation of paracetamol using modified GC electrode remain constant even after 15 cycling. It is therefore evident that the MgB2modifiedGCelectrode possesses some degree of stability. A slope of 0.52 dependent of scan rate on current indicates that the system undergoes diffusion-controlled process.

Preparation of Copper Doped L-Threonine Modified Electrode and its Application in Determination of Hydroquinone

2013 ◽  
Vol 813 ◽  
pp. 413-418
Author(s):  
Yue Hua ◽  
Zong Rong Song ◽  
Jia Hong He ◽  
Ying Zhang ◽  
Cheng Bo Hu
Keyword(s):  
Cyclic Voltammetry ◽  
Modified Electrode ◽  
Supporting Electrolyte ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Determination Method ◽  
Scan Rate ◽  
Anodic Peak Current ◽  
Pulse Voltammetry

A copper doped L-threonine modified electrode was prepared by cyclic voltammetry (CV), and the electrochemical behavior of hydroquinone at the modified electrode had been studied. A novel determination method of hydroquinone using CV, chronoamperometry and differential pulse voltammetry (DPV) was established, and the scan rate and supporting electrolyte factors on catalytic oxidation of hydroquinone in modified electrodes were discussed. The results revealed that the modified electrode had showed obvious electrocatalytic activity for hydroquinone, and anodic peak current increased linearly with the concentration of hydroquinone in the range of 0.8-150 μmol/L with the detection limit of 0.4 μmol/L (S/N=3). The method has been applied to the determination of hydroquinone in water sample with satisfactory results.the recovery ranged from 95.9 % to 105.2 %.

scholarly journals Novel cyclic voltammetry behavior of 3-((benzothiazol-2- diazenylnaphthalene-2,7-diol and use it for spectrophotometric determination of copper (II )in honey sample

2017 ◽  
Vol 12 (7) ◽  
pp. 4243-4255
Author(s):  
Fatma .A. Khazaal ◽  
Hussein. J. Mohammed ◽  
Muhammed . M.Radhi
Keyword(s):  
Cyclic Voltammetry ◽  
Spectrophotometric Determination ◽  
Glassy Carbon ◽  
Supporting Electrolyte ◽  
Honey Sample ◽  
Spectral Techniques ◽  
Scan Rate ◽  
Ft Ir ◽  
Determination Of Copper

The azo reagent 3-((benzothiazol-2-diazenylnaphthalene-2,7-diol] was synthesized and characterized by FT-IR ,1H-NMRand 13CNMR spectral techniques. The electrochemical behavior of the azo reagent and its complex with Cu (II) has beenstudied at glassy carbon disk GCE electrode in different supporting electrolyte at concentration (1M) and scan rate(100mv.s-1). Spectrophotometric determination of copper (II ) is based on the formation of a 2:1 complex with abovereagent. The complex has λmax at(588) nm and Ԑmax of( 1.436x104)L.mol-1.cm-1 .A linear correlation (0.1 – 3.0 μg. ml-1) was found between absorbance at λmax and concentration . The effect of diverseions on the determination of copper (II) to investigate the selectivity of the method were also studied . The stabilityconstant of the product was (1.1x108 ) . The proposed method was successfully applied to the analysis of honey sample .

scholarly journals Modification of Carbon Paste Electrode Using Calyx[6]Arene-TiO2 Nanocomposite for Determination of Cu2+ ion Based on Cyclic Voltammetry

2021 ◽  
Vol 12 (3) ◽  
pp. 2843-2851
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Supporting Electrolyte ◽  
Rate Variation ◽  
Carbon Paste ◽  
Relative Standard ◽  
Scan Rate ◽  
Paste Electrode

In the present study, an electrochemical sensor for the determination of Cu(II) ions in aqueous solutions was introduced. This study proposes an electrochemical method using the calyx [6]arene-TiO2 nanocomposite modified carbon paste electrode (calyx[6]arene-TiO2/CPE) for the determination of metal Cu2+ ion. Calyx[6]arene-TiO2 were synthesized using the hydrolysis method as the Cu-binding ionophore. The electrode surface was studied by scanning electron microscopy (SEM), and the reduction and oxidation processes were studied by cyclic voltammetry (CV) techniques. The effect of modifier composition, scan rate, variation concentration, repeatability, and type of supporting electrolyte on the determination of metal ions was investigated. The best composition was 0.005 g calyx[6]arene-TiO2 in the carbon paste electrode with a scan rate of 0.5 V/s. The modified electrodes showed good performance for Cu2+ ion detection. Under optimum experimental conditions, a linear range for metal Cu(II) ions was from 0.1, 0.3, 0.5, 0.8, and 1.0 ppm with respective currents of 500, 550, 600, 700, and 800 µA. The limit of detection (LOD) for metal Cu2+ ions is found to be 0.022 ppm with a relative standard deviation (%RSD) of 0.011%.

On the theory of cyclic voltammetry for multiple nucleation and growth: Scan rate influence

2021 ◽  
Vol 883 ◽  
pp. 115056
Author(s):  
Alexander V. Kosov ◽  
Olga V. Grishenkova ◽  
Olga L. Semerikova ◽  
Vladimir A. Isaev ◽  
Yurii P. Zaikov
Keyword(s):  
Cyclic Voltammetry ◽  
Nucleation And Growth ◽  
Scan Rate

scholarly journals Surfactant-free synthesis of carbon-supported silver (Ag/C) nanobars as an efficient electrocatalyst for alcohol tolerance and oxidation of sodium borohydride in alkaline medium

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Santanu Dey ◽  
Pradipta Chakraborty ◽  
Dhiraj Kumar Rana ◽  
Subhamay Pramanik ◽  
Soumen Basu
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Alkaline Medium ◽  
Sodium Borohydride ◽  
Metallic Silver ◽  
Alcohol Tolerance ◽  
Current Ratio ◽  
X Ray ◽  
Scan Rate ◽  
Borohydride Oxidation

AbstractWe have synthesized carbon-supported silver (Ag/C) nanobars by a simple surfactant-free hydrothermal method using glucose as the reducing reagent as well as the source of carbon in Ag/C nanobars. Physicochemical characterization of the materials was performed by X-ray Diffraction (XRD), field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The XRD pattern confirmed the presence of a pure metallic silver phase. No carbon phase was detected, which indicates that the carbon exists mainly in the amorphous form. The electrocatalytic activity of Ag/C in different electrolyte solutions such as 0.5 M NaOH, 0.5 M NaOH + 1 M ethanol (EtOH), 0.5 M NaOH + 1 M ethylene glycol (EG), and 0.5 M NaOH + 0.01 M NaBH4 (sodium borohydride) was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) study. Alcohol tolerance of the catalysts was also established in the presence of ethanol and ethylene glycol. The forward-to-backward current ratio from cyclic voltammetry (CV) study of Ag/C-20 (20 h) in 0.5 M NaOH + 1 M ethanol solution at 100 mV s−1 scan rate is 4.13 times higher compared to that of Ag/C-5 (5 h). Hence, Ag/C-20 is a better candidate for the tolerance of ethanol. In the presence of ethylene glycol (1 M) in 0.5 M NaOH solution, it is obtained that the forward-to-backward current ratio at the same scan rate for Ag/C-20 is lower than that in the presence of ethanol. The durability of the catalyst was studied by chronoamperometry measurement. We studied the electrochemical kinetics of Ag/C catalysts for borohydride oxidation in an alkaline medium. The basic electrochemical results for borohydride oxidation show that Ag/C has very well strength and activity for direct borohydride oxidation in an alkaline medium. The reaction of borohydride oxidation with the contemporaneous BH4−. hydrolysis was noticed at the oxidized silver surface. Among all the synthesized Ag/C catalysts, Ag/C-20 exhibited the best electrocatalytic performance for borohydride oxidation in an alkaline medium. The activation energy and the number of exchange electrons at Ag/C-20 electrode surface for borohydride electro-oxidation were estimated as 57.2 kJ mol−1 and 2.27, respectively.

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