Analytical & Bioanalytical Electrochemistry
Volume:11 Issue: 7, Jul 2019

The corrosion inhibition of copper CDA 110 in 3% NaCl by Ruta Chalepensis’ extract is studied by using electrochemical stationary and non-stationary methods. The obtained results reveal a significant enhancement of the inhibition efficiency by increasing the extract concentration. The adsorption behavior is found to obey Langmuir isotherm. Polarization study shows a cathodic character for the green leaves. The increase of medium temperature accelerates the corrosion process. The values of activation energy and thermodynamic parameters are calculated. In-depth the first principles calculations based on density functional density have been performed in order to evaluate the electronic structure and to understand the corrosion mechanism

Polymer-based solid electrolytes have a potential electrochemical application in energy conversion and storage devices. In this investigation, polyurethane and its solid polymer electrolytes were prepared by an eco-friendly cost-effective method using vegetable oils. The neem oil-based polyurethane (PU) was prepared by polycondensation method. The polyurethane and the corresponding solid polymer electrolyte (SPE) were characterized by FT-IR, 1H NMR, GPC, XRD, SEM, TEM. The conductivity of PU/PVP-xLiClO4 was measured using electrochemical impedance spectroscopy. The ionic conductivity of the SEPs with different LiClO4 composition shows a higher value for 15% LiClO4 composition. The thermal analysis was carried out study the stability of the prepared PU and its SPEs. The Stability constant for PU was higher than the composite due to the segmental motion in the PU

The abrasion-corrosion behavior of the alloy 31 was tested at different temperatures 25 °C, 40 °C, 60 °C and 80 °C in polluted phosphoric acid medium. Electrochemical measurements were investigated using techniques such as electrochemical impedance spectroscopy and potentiodynamic polarization. In order to determine the oxides and hydroxides formed at the interface of the alloy, we opted for surface treatment techniques:SEM-EDX, UV-Vis-NIR spectroscopy, and X-ray diffraction. The results showed an increase in current densities, which means that these conditions favor the hydrogen evolution reaction and influence the parameters of the passive film. Moreover, this effect can be explained by an increase in the activity of the aggressive ions adsorbed on the surface, thereby accelerating the dissolution process and the exchange kinetics between the electrode surface and the electrolyte. UV-Vis-IR spectroscopy and X-ray diffraction analysis exhibited that temperature favors the formation of metal oxides on the surface, which the EIS discloses that film was less protective.

In this study novel tetra furfurylamide substituted metal phthalocyanine (M=Co, Cu, Ni & Zn) were synthesized and characterized by elemental analysis, Ultra-violet, Fourier transfer infrared spectroscopy, mass spectroscopy and powder X-ray diffraction analysis. The cobalt (II) tetra furfurylamide phthalocyanine (CoTfurNH2Pc) tailored GCE was constructed by drop covering technique. The fabricated electrode was subjected for electrochemical investigation of oxidizable species such as dopamine (DA), uric acid (UA) and reducible moiety like dimetridazole (DMZ). It was noticed that CoTfurNH2Pc/GCE exhibits admirable electrochemical performance for dopamine, uric acid oxidation and dimetridazole reduction in PBS pH 7.0. The sensor exhibits sensitivity for DA (CV 0.179, DPV 0.333, CA 0.486 μA μM-1cm-2), for UA (CV 0.517, DPV 0.374, CA 0.129 μA μM-1cm-2), for DMZ is (CV -8.55, DPV -13.73, CA -0.393 μA μM-1cm-2) respectively (S/N=3). Biomolecules present in same solution can be sensed by constructed electrode with peaks resolution of 348 millivolts and 318 millivolts for dopamine-dimetridazole and dimetridazole-uric acid respectively. The
CoTfurNH2Pc fabricated electrode has various useful properties like high repeatability, quick response and steadiness. Further DPV and chronoamperometric of titled compound has been studied.

The action of inhibition of the essential oil of Eucalyptus camaldulensis and Myrtus Communis on aluminum corrosion in a 1 M HCL solution in a temperature range of 288 to 318 K was measured using the methods of the polarizing Potentiodynamic and Spectroscopy of Electrochemical impedance. The acquired results prove that the both oils prevents the corrosion of aluminum in solution of 1M HCL and that the efficiency of the inhibition increases by the augment of the concentration of the oils to attain 88.43% for Eucalyptus oil and 89.06% for Myrtle oil at 1000 ppm, as well as decreases proportionally by the augment of the temperature. Potentiodynamic polarization studies show that the inhibitors are anodic. The values of dissolution kinetics were studied. The results obtained showed that the essential oil of E. camaldulensis and M. Communis (Myrtaceae), might serve as effective inhibitors of the corrosion of aluminum in hydrochloric acid solution.

The exploitation of undemanding modifications needed for rising the sensitivity and functionality of nanobiosensors is still remaining a challenge. Conventional enzyme-based sensors propose favorably selective and sensitive determination of glucose at the outlay of low stability. Thus, promoting the comfortable, sensitive, rapid and consistent strategies play an impressive role for determining the human glucose level. Here, a new nanocomposite, X-Fe2O4- Buckypaper-Chitosan (X=Fe3O4, ZnFe2O4 and CuFe2O4), was scrutinized to find an appropriate substrate for nonenzymatic biosensing. The nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM). The average particle size of all nanoparticles was lower than 100 nm. The Cu-Fe2O4-buckypaper-chitosan composite has shown a significant electrochemical behavior compared with the other composites. The biosensor was applied to detect glucose with a linear range of 0.25×10−3–17×10−3 M and detection limit is 0.025 μM.
The biosensor presented reasonable results for glucose at applied potential of 0.575 V with a fast response time (<4 s). This is the first research on the X-Fe2O4-Buckypaper-Chitosan biosensing application and its abovementioned sensing characteristics are comparable with those heretofore reported developments.

In this paper, a new cobalt selective liquid membrane electrode has been constructed by using a new synthesized oxime-2-(1-cyclohexenyl) cyclohexanone in a poly (vinyl chloride) matrix. The electrode was shown a good Nernstian response for Co2+ (32.1±0.5) over a concentration range of (3.0×10-2 to 7.0×10-7 mol L-1). The electrode detection limit was 6.0×10-7 mol L-1. The response time of electrode was fast (∼10 s) and useful working pH range was 3.5-8.5. It can be used over a period of 15 weeks without any divergence in potential. The proposed electrode revealed good selectivity for Co2+ over a wide variety of other metal ions. The Co2+ ion sensor has been practically utilized as an indicator electrode in potentiometric titration of Co2+ with EDTA. Also, direct determination of Co2+ in water and battery wastewater samples was done to confirmation of analytical ability of electrode

The cadmium removal from phosphoric acid using a hybrid process combining ion exchange resin and electrodialysis called electropermutation was investigated. Continuous electropermutation has been shown to be more effective than conventional electrodialysis with a cadmium removal rate of 70.70% versus 13.70%. The study of the influence of some operating parameters on continuous electropermutation has revealed that the cadmium removal efficiency increases with the applied current density, and the flow rate of the feed solution. However, the efficiency  decreases as the phosphoric acid and cadmium concentration increases. The cation exchange resin and the electroregeneration electrolyte nature also have an effect on the continuous  electropermutation efficiency. The Duolite C20 resin and the HNO3 electroregeneration electrolyte were found to be more effective in removing cadmium from phosphoric acid by continuous electropermutation

The corrosion inhibition performances of some quinoline derivatives corrosion inhibitors on mild steel in acidic medium, namely, 5-((4-chlorophenyl)-benzimidazol-1-yl)- methyl)-quinolin-8-ol (Q-Cl) and 5-((2-phenylbenzimidazol-1-yl)-methyl)-quinolin-8-ol (Q-H) on the corrosion of mild steel were investigated in this work by using electrochemical and quantum chemical calculations. The experimental results confirmed by Electrochemical impedance spectroscopy and potentiodynamic polarization measurements show that (Q-Cl) may exhibit the best inhibitive performance among (Q-H) for mild steel in hydrochloric acid solution. Furthermore, quantum chemical calculations of density function theory (DFT) and Actives sites (Fukui function) for quinoline derivatives were applied to theoretically determine the relationship between molecular structure and inhibition efficiency. 5-((4-chlorophenyl)- benzimidazol-1-yl)-methyl)-quinolin-8-ol (Q-Cl) shows the highest reaction activity among the 5-((2-phenylbenzimidazol-1-yl)-methyl)-quinolin-8-ol (Q-H) molecule. The binding energies of the corrosion inhibitor molecules and iron surface follow the order of Q-Cl > Q-H, which agrees well with the experimental findings

Hydrazine is a colorless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic and dangerously unstable. In this study, a novel electrochemical sensor was proposed for detection of hydrazine on glassy carbon electrode (GCE). The electrochemical sensor is based on immobilizing titanium dioxide nanoparticle/alizarin yellow R/ Chitosan (TiO2 NPs/AYR/chit) nanocomposite. The deposited nanocomposite on the GCE was characterized by scanning electron microscopy (SEM). Then its electrocatalytical activity were investigated by CV and amperometry methods. Tests show that TiO2 NPs/AYR/chit exhibited enhanced catalytic activity towards hydrazine oxidation under optimal conditions. The results show the linear dependence of electrocatalytic response current of the sensor with the hydrazine concentration in the ranges of 5 to 580 μM, with a limit of detection and sensitivity of 3 μM and 0.1727 μA/μM, respectively. The modified GCE show many advantages relative to previously reported hydrazine biosensors such as facile preparation, highly sensitive and good catalytic properties at pH 12