The electrochemical Oxidation of 4-nitrocatechol in aqueous media was studied using Cyclic voltammetry. The results indicate that the stability of electrochemically generated o-nitrobenzoquinone is low and decreases with increasing pH. Also, our voltammetric data show that the species produced from the conversion of o-nitrobenzoquinone are electro-inactive in the studied potential range. In addition, the results reveal that the rate of conversion of o-nitrobenzoquinone is dependent on the nature of the solvent. According to EC mechanism, the observed homogeneous rate constant of the conversion of o-nitrobenzoquinone was estimated by comparing the experimental Cyclic voltammograms with the digitally simulated results. Finally, a possible mechanism is proposed for the electrode process, on the basis of the present and previous investigations.

The electrochemical Oxidation behavior of m-nitrophenol (m-NP) was studied comparatively on glassy carbon electrode, Pt electrode, PbO2 electrode, SnO2 electrode, and graphite electrode using Cyclic voltammetry. The Cyclic voltammetry measurements were performed in acidic (1 M H2SO4, pH 0. 4), neutral (1 M Na2SO4, pH 6. 8), and alkaline (1 M NaOH, pH 12. 0) media to investigate the effect of pH value on the Oxidation of m-NP. The fouling of electrodes was also studied during Cyclic voltammetry measurements. The results indicate that both of the electrode material and the pH value of supporting electrolyte had significantly influence on the Oxidation of m-NP. In acidic medium, m-NP was irreversibly oxidized on glassy carbon electrode, Pt electrode, SnO2 electrode, and graphite electrode at 1. 23, 1. 26, 1. 26 and 1. 27 V, respectively, while there was no any Oxidation peak for PbO2 electrode. In a neutral medium, m-NP yielded well-defined Oxidation peaks on all electrodes, although the height and potential of the peaks depended on the material of electrodes. In the alkaline medium, the m-NP could be directly oxidized only on glassy carbon electrode and graphite electrode, but their peaks were not well defined because the Oxidation of m-NP occurs closer to oxygen evolution potential region. In addition, the Oxidation peaks appeared at the lower potential value in the alkaline medium than in neutral and acidic media. Under all conditions, except in the alkaline solution and on glassy carbon electrode, the passivation of electrodes occurred during continual scans.

In order to improve the Oxidation resistance of ferritic stainless steel, it is possible to deposit a protective coating onto the steel substrate. In this research, through the usage of pack cementation method a coating of titanium was applied on the surface of AISI 430 stainless steel. Scanning Electron-Microscopy (SEM), Energy-Dispersive X-ray spectrometry (EDAX) and X-ray diffraction (XRD) were used for evaluating of coating structure. Results showed that titanium coating consisted of two layers with the total thickness of 50 micron. The titanized layer consisted of TiFe, TiFe2 and Fe2TiO5 phases. For investigating the Oxidation behavior of the coated and uncoated specimens, isothermal and Cyclic Oxidation tests were performed at 1000  C. In isothermal Oxidation, the Oxidation resistance of the titanium coated specimens was improved by restricting the outward penetration of chromium cation. The results of Cyclic Oxidation of titanium coated samples indicated that they were resistant to lamination and cracking.

In this study, aluminide coating was employed to enhance the high-temperature Cyclic Oxidation of Rene-80 superalloy at 950º C. The microstructural aspects and phase constituents of samples were investigated with scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques. The result of Oxidation tests showed that the weight gain in the uncoated sample was considerably higher than the aluminide coated sample, which indicates the higher rate of oxide formation on the uncoated surface. With the aid of microstructural and XRD analysis, it was confirmed that with the increment of Oxidation cycles, the thickness of aluminide coating reduced and the protective β-NiAl phase was converted to alumina scales. According to the EDS results taken from the top coat, it was found that with the increase of Oxidation cycles, the content of aluminum in the top layer was drastically decreased and the weight percentage of oxygen was considerably enhanced. Also, in higher Oxidation cycles, other protective elements such as Cr and Ti outwardly diffused from the inter-diffusion zone (IDZ) layer which led to reduction in the content of these elements in inner zones of the aluminide coating.

In this study, the Cu nanoparticles were prepared by reducing CuSO4. These particles were used in making copper nanoparticles modified carbon paste electrode (nano-CPE). The electrochemical characteristics of this electrode (nano-CPE) were investigated. The results of the electrocatalytic Oxidation of theophylline (TP) on nano-CPE, using Cyclic voltammetry technique showed that nano-CPE, has more reactivity and more effective surface area, as compared to the unmodified carbon paste electrode (un-CPE). The investigation of voltammograms obtained from Oxidation of TP at different scan rates on the nano-CPE confirmed a Cyclic mediated redox mechanism followed by reducing Cu(III) which is a chemical reaction (EC mechanism). These species formed in more positive potentials and act as a redox intermediate for TP Oxidation. There was a linear relationship between the Oxidation peak current and the square root of scan rate, showing that the Oxidation reaction of TP at nano-CPE might be due to the diffusion-controlled process.