فهرست مطالب

Analytical & Bioanalytical Electrochemistry - Volume:11 Issue:6, 2019
  • Volume:11 Issue:6, 2019
  • تاریخ انتشار: 1398/03/25
  • تعداد عناوین: 10
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  • Hamid Reza Naderi, Amir Ghaderi, Zeynab Sadat Seyedi, Mohammad Eghbali Arani * Pages 679-690

    Here in, CeMoO4 nanostructure were successfully prepared by a co-precipitation route without capping agent. The characterization and morphological of as-prepared samples were examined by Fourier transform infrared spectroscopy, filed emission scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. SEM and XRD results show that CeMoO4 nanostructure obtained with average nano-plate thickness 30 nm and average crystal size of 10 nm. The evaluations on CeMoO4-based electrodes revealed the material to have a specific capacitance (SC) of 327 F g-1 at a scan rate of 2 mV s-1, an energy density of 24.5 W h kg-1, and a high rate capability. Continues cyclic voltammetry evaluations using CeMoO4-based electrodes proved the electrodes to be capable of maintaining almost 96.3% of its initial SC after 4000 cycles. To the best of our knowledge, this study is considered as the start point of using lanthanide molybdates as an electrode materials for supercapacitors and the results obviously consent to outstanding properties of CeMoO4 for the mentioned application.

    Keywords: CeMoO4, Nanostructure, Co-precipitation, Supercapacitor
  • Hilfi Pardi *, Deswati, Hamzar Suyani, Tri Widya Edelwis Pages 691-702

    In this work, a selective and sensitive method to the determination of essential elements Cu and Zn in drinking water proposed by adsorptive stripping differential pulse cathodic voltammetry (AdSDPCV) using Alizarin (AZ) as a ligand. The complexes of metals-AZ were deposited onto a hanging mercury drop electrode (HMDE) and the resulting current was analyzed. Increase peak current of metals-AZ obtained optimization condition of pH 6, AZ concentration0.04 mmol/L, supporting electrolyte concentration0.5 mol/L, potential for adsorptive deposition (Eads) -0.1 V, the time for adsorptive deposition (tads)70 s, respectively, the instrumental parameters (drop size of mercury 8 and scan rate 800 ms/V). The linearity of metals were160 ng/L and 200 ng/L, the limit of detection 0.1 ng/L for Cu and 0.05 ng/L for Zn, respectively. Relative standard deviation (RSD) 0.5% for Cu and 0.7% for Zn and recovery Cu and Zn in the range 98 to 101%, respectively. The applicability of AdSDPCV methods is successfully for determination of metals in drinking water.

    Keywords: Adsorptive stripping differential pulse cathodic voltammetry, Heavy metal, Alizarin, Differential pulse, Drinking water
  • Razieh Chaharmahali, Kazem Babaei, Arash Fattah alhosseini * Pages 703-714

    In this study, plasma electrolytic oxidation (PEO) coating on AZ31B magnesium alloy, being in electrolyte of sodium phosphate with various calcium hydroxide concentrations was investigated. To do this, phosphate electrolytes having diverse calcium hydroxide concentrations of 1, 2 and 3 gram per liter were studied. The coated specimens microstructure studies and chemical composition were carried out using scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). In order to study the corrosion behavior of created coatings in various conditions, Potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS) were measured in body simulated physiological solution. The results displayed that the highest corrosion resistance was achieved in the sample having 2 g/l calcium hydroxide with the lowest porosity and corrosion current density (2.23×10-6 A/cm2).

    Keywords: AZ31B magnesium alloy, Corrosion resistance, Plasma electrolytic oxidation, Calcium hydroxide
  • Khadija Mouflih, Maria Boudalia, Abdelkbir Bellaouchou, Abdellah Guenbour, Abdelkader Zarrouk*, Mohamed Tabyaoui Pages 715-726

    The purpose of this study was to investigate the effect of Juglans regia extract concentration on the corrosion behavior of Ni-Cr dental alloy in artificial saliva (AS) using potentiodynamic polarization (PDP), Impedance spectroscopy (EIS) and their surfaces were analyzed by optical microscopy (OM). The presence of Juglans regia extract in artificial saliva had a significant influence on the corrosion rate, the icorr value increased and linear polarization resistance (LPR) decreased in artificial saliva (AS) medium, but in the presence of Juglans regia extract the corrosion resistance of this alloy improved. Impedance measurements confirm the anti-corrosion ability by adding the extracted plant and this is correlated to the enlargement of capacitive loops. The optical microscopic studies show the formation of a film on Ni-Cr dental alloy surface in the presence of the plant extract.

    Keywords: Ni-Cr dental alloy, Artificial saliva medium, Corrosion inhibition, Juglans regia extract, Electrochemical techniques, Optical microscopy
  • Behrooz Zargar *, Zohreh Ghanavatizadeh, Amir Hatamie Pages 727-741

    A new electrochemical probe for detecting Isoniazid is proposed based on nanocomposite electrode modified with nanoceria particles (CeO2 NPs) as a catalytic amplifier. The main reason for the catalytic activity of CeO2 NPs attributed to their reversible dual oxidation states Ce(III)/Ce(IV) in that CeO2 NPs. Nanoceria nanoparticles have the ability to change redox states and surface properties when being in contact with electroactive compounds. Therefore, valence and defect structure of CeO2 NPs play a mainly role in this electrocatalytic reaction. Electrode surface area (A), electron transfer coefficient (α), and heterogeneous catalytic rate constant (Kh) were estimated by electrochemical techniques. The peak current is found to depend linearly on isoniazid concentration within the ranges of 5.0-140.0 μmol L–1. The limit of detection (LOD) for isoniazid is found to be 0.51 μmol L–1. Finally, the modified electrode receives many advantages such as notable catalytic activity, and acceptable reproducibility, the proposed method was used for determining isoniazid in urine and tablet samples successfully.

    Keywords: Electrochemical sensor, Isoniazid, Antituberculosis tablet, Electrocatalytic sensing, Nanoceria particles
  • Nambudumada S. Prinith, Jamballi G. Manjunatha*, Chenthattil Raril Pages 742-756

    In this work, Poly (adenine) film modified carbon nanotube paste electrode (PAEMCNTPE), prepared by electropolymerization of adenine on a carbon nanotube paste electrode, applied for the sensitive and selective analysis of dopamine (DA), Uric acid (UA) and Ascorbic acid (AA) based on cyclic voltammetric technique. The polyadenine modified carbon nanotube paste electrode has presented with an impressive electrocatalytic activity towards oxidation of DA, UA, and AA in the presence of supporting electrolyte, 0.2 M PBS pH 6.5. The surface of fabricated sensor displayed with a permselective layer with transducing, anti- interfering and anti-fouling properties followed by solving the overlapped peaks of DA, AA and UA obtained from the conventional electrode by presenting with distinct three anodic peaks. The result of this electrochemical sensor displayed with excellent sensitivity, selectivity, reproducibility, repeatability and highly stable. The detection limit for DA was 6.7×10-7 M. Further; this fabricated electrode was carried out for the quantification of DA in the real sample.

    Keywords: Carbon nanotube electrode, Polyadenine, Electropolymerization, Dopamine, Cyclic Voltammetry
  • Maryam Banaei, Ali Benvidi *, Zohreh Abassi, Marzieh Dehghan Tezerjani, Ali Akbari Pages 757-773

    Here, the electrochemical carbon sensor modified with titanium oxide (TiO2) nanoparticles and 5-Chloro, 2, 4-dihydroxyphenyl imidazo [4,5-d] [1,3] thiazin 7(3H)-one, an imidazole derivative, (CHIT) was fabricated for hydroxylamine (HX) determination. After optimization, some kinetic parameters related to CHIT were obtained. The observations revealed that using CHIT with TiO2 nanoparticle affected in lowering value of oxidation potential and increasing of oxidation peak currents, which provides higher sensitivity. According to these results CHIT-TiO2-CPE sensor possess the linear range (0.5–850 μM) (0.5-40 and 40-850 μM) and a low detection limit (DL) 0.08 μM according to 3sb/m. Also CHIT-TiO2-CPE was used for determination of phenol in the range of 90 μM to 800 μM in the presence of various concentration of HX. Also, the CHIT-TiO2-CPE was used in water samples, successfully.

    Keywords: Hydroxylamine, Phenol, Titanium oxide nanoparticles, Modifier, Electrochemical sensor
  • Ghodsiyeh Sadat Ferdowsi *, Majid Rahgozar, Seyed Abolfazl Seyed Sadjadi, Ali Ghaffarinejad Pages 774-786

    In this article, the effect of the electrode surface morphology is investigated in the methanol electrooxidation process. For this purpose, a Ni-P layer of fine structure and two different Ni-B coatings having granular and cauliflower surface morphologies were plated separately on the graphite electrodes (GEs). The surface structure of samples was investigated by scanning electron microscopy (SEM) and their elemental analysis was done with electrode dispersive energy analysis (EDS). Then these modified electrodes were used as the anode for methanol oxidation reaction (MOR) in alkaline solution. Electrochemical studies were accomplished with cyclic voltammetry (CV) and chronoamperometry (CA) methods. Studies have shown, these different structures make a difference in the electrocatalytic performance of the electrodes and the highest methanol oxidation efficiency is related to Ni-B electrode with granular morphology. In order to reveal the methanol oxidation mechanism, coordination of anodic and cathodic peaks in CV diagrams was studied. Based on the results, we have offered the mechanism proposed by Fleischmann et al.

    Keywords: Ni-Electroless, Methanol oxidation, Graphite electrode, Electrocatalyst
  • Mohamed Rbaa *, Brahim Lakhrissi, Hassane Lgaz Pages 787-811

    Two newly substituted quinoline derivatives, namely 5-(((2-hydroxyethyl) thio) methyl) quinolin-8-ol Q-OH and 5-(((2-aminoethyl) thio) methyl) quinolin-8-ol Q-NH2 were synthesized and characterized by elemental analysis data, 1H and 13C Nuclear Magnetic Resonance Spectroscopy. Their inhibitory performance was studied against the corrosion of mild steel in 1.0 M hydrochloric acid at 298 K. Data obtained from EIS measurements has been examined and characterized by weight loss, Tafel polarization and electrochemical impedance spectroscopy (EIS). The experimental results reveal that the studied compounds have good inhibiting effects on the corrosion for mild steel in 1.0 M HCl medium. The protection efficiency increases with increasing inhibitor concentration but decrease with temperature. Good agreement between the results obtained from weight loss and electrochemical measurements. It has been determined that the adsorption for the studied inhibitors on mild steel complies with the Langmuir adsorption isotherm at all studied temperatures. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption, respectively, were determined and discussed. On the bases of thermodynamic adsorption parameters, comprehensive adsorption (physisorption and chemisorption) for the studied inhibitors on mild steel surface was suggested. Results show that the order of inhibition efficiency is Q-OH > Q-NH2. Potentiodynamic polarization studies have shown that compounds studies acts as a mixed type of inhibitor’s. However, in order to get information on bonding mechanism of mild steel surface/ inhibitors/1.0 M HCl solution system, the corrosion protection was also investigated by UV-visible spectrophotometry. Scanning Electron Microscopy was also performed and discussed for surface morphology study of mild steel samples.

    Keywords: Synthesis, NMR, Elemental analysis, Quinoline, Mild steel, HCl, Corrosion, Electrochemical techniques, Weight loss, UV-visible spectrophotometry, SEM
  • Fatemeh Ahour * Pages 812-829

    A novel nanocomposite consisting of graphene oxide (GO), palladium nanoparticles (PdNPs) and Prussian blue (PB) was used to fabricate a non-enzymatic hydrogen peroxide (H2O2) sensor. A pencil graphite electrode (PGE) was modified with the mentioned nanocomposite (PB/Pd/GO-PGE) and characterized by several techniques including scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The sensor showed a significant better electrocatalytic activity for the reduction of hydrogen peroxide in comparison with the single GO-PGE, PB/GO-PGE and Pd/GO-PGE. This was attributed to the synergistic effect of PB, Pd, and GO nanoparticles. The values of diffusion coefficient, D, and electroreduction kinetics parameters including electron transfer coefficient, , and catalytic rate constant, k, were 9.61×10-6 cm2 s-1,0.5 and 7.02×105 cm3 mol-1 s-1 respectively. Furthermore, the proposed sensor demonstrated a high level of the overall performance for the analysis of H2O2 using hydrodynamic amperometry in the concentration range from 0.2×10-6 to 0.5×10-3 mol L-1 and detection limit of 0.078×10-6 mol L-1 with good stability, repeatability, and selectivity. This modified electrode was also used successfully for the determination of H2O2 in real samples such as, mother’s milk, and rain water.

    Keywords: Prussian blue, Hydrogen peroxide reduction, Electrocatalysis, Graphene oxide, Pd nanoparticles