A highly efficient catalyst consisting of Ni and S double-doped reduced graphene modified with ZnO nanoparticles for hydrogen peroxide electroreduction
Sedef Kaplan A, Rukan Suna Karatekin A
n this study, we prepared a novel electrocatalyst based on S doped reduced graphene layer modified with Ni and ZnO nanoparticles. The catalyst materials were characterized by X-ray Powder Diffraction (XRD), Raman spectroscopy, UV–vis spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and mapping. Because of the synergistic effect between three materials (S, Ni, and ZnO), the new electrocatalyst finally formed with a large electroactive surface area. Through the measurement, it was concluded that this surface includes large active sites which can effectively improve the electron transfer rate. The electrocatalytic activity of Ni-ZnO@s-rGO toward H2O2 reduction was examined via some measurements such as CV, I-t measurement, and electrochemical imped...
Corrosion inhibition of indole-3-acetic acid on mild steel in 0.5 M HCl
Avcı, Gülşen
Corrosion inhibition of indole-3-acetic acid on mild steel in acidic medium (0.5 M HCl) containing the desired amount of inhibitor has been investigated at different temperatures by using potentiodynamic polarization, electrochemical impedance spectroscopy, and polarization resistance measurements. The experimental results showed that corrosion potential shifted toward a more negative potential region in the presence of indole-3-acetic acid than that of blank solution. According to the obtained results from all measurements, inhibition efficiency was about 77% with 1.7 × 10−3 M inhibitor present, increasing to about 93% at the 1 × 10−2 M inhibitor concentration. Potentiodynamic polarization measurements showed that the current at anodic and cathodic regions obtains a smaller value in the p...
Aqueous extract of Acacia cyanophylla leaves as environmentally friendly inhibitor for mild steel corrosion in 1 MH2SO4 solution
Gülşen Avcı, Yüksel Keleş
The efficiency of Acacia cyanophylla leaves extract as an environmentally friendly inhibitor for mild steel in aerated aqueous 1M H2SO4 solution has been investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy techniques. Addition of inhibitor decreases the corrosion current whereas the corrosion potential values show slight shifts in positive directions. Inhibition efficiency was found to be about 93% (the maximum value was determined from the polarization curve). Efficiencies obtained from both electrochemical techniques are in good agreement. Adsorption of acacia cyanophylla leaves extracton mild steel surface in 1 M H2SO4 solution obeys Langmuir adsorption isotherm. Polarization curves were also obtained at different temperatures in order to...
Gülşen Avcı sciencedirect.com alanından [HTML] Inhibitor effect of N, N′-methylenediacrylamide on corrosion behavior of mild steel in 0.5 M HCl
Avcı, Gülşen
N,N′-Methylenediacrylamide has been evaluated as a corrosion inhibitor for mild steel electrodes in 0.5 M HCl solution using potentiodynamic polarization, electrochemical impedance spectroscopy, and polarization resistance measurements. According to the experimental results, inhibition efficiency increased with increasing inhibitor concentration. Potentiodynamic measurements showed that the presence of inhibitor molecules decreases cathodic and anodic currents and shifts corrosion potential to a more positive potential region. Adsorption of the inhibitor molecules to the mild steel surface obeyed the Langmuir adsorption isotherm. Adsorption free energy was calculated from the adsorption isotherm as −26.8 kJ mol−1. The negative value of ΔGads showed that the adsorption process is spontaneou...