scholarly journals Enhancement of Photoelectrochemical Cathodic Protection of Copper in Marine Condition by Cu-Doped TiO2

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 146 ◽  
Author(s):  
Pailin Ngaotrakanwiwat ◽  
Piyapol Heawphet ◽  
Pramoch Rangsunvigit

Photochemical cathodic protection (PEC) efficiency was enhanced by doping TiO2 with Cu (Cu/TiO2) through impregnation and reduction under hydrogen. The Cu loading was vaired from 0.1 to 1.0 mol% (0.1 Cu/TiO2, 0.5 Cu/TiO2, 1 Cu/TiO2). Then, up to 50 wt% Cu/TiO2 was mixed with TiO2 to form nanocomposite films. The film photocurrent and photopotential were measured under 1 mW/cm2 UV irradiation. The Cu/TiO2 film with 10 wt% of 0.5 Cu/TiO2 exhibited the highest photocurrent of 29.0 mA/g, which was three times higher than the TiO2 film. The underlying reason for the high photocurrent was the lower photopotential of film than the corrosion potential of copper for PEC. This film was also applied on copper terminal lug for anti-corrosion measurement by Tafel polarization in 3.5 wt% NaCl solution. The results showed that the photopotential of terminal lug coated with the film was −0.252 V vs. Ag/AgCl, which was lower than the corrosion potential of copper (−0.222 V vs. Ag/AgCl). Furthermore, the film can protect the corrosion of copper in the dark with 86.7% lower corrosion current (icorr) than that of bare copper.

2013 ◽  
Vol 704 ◽  
pp. 114-119
Author(s):  
Jing Feng ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  

The microstructure and electrochemical properties of Ce-containing 7072 Al alloy were investigated through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Tafel polarization analysis. It was found that Ce alloying could result in a formation of finer grains in the simulated brazing alloys. The 7072 Al alloy with 0.15% Ce had desirable distribution of precipitates. The electrochemical testing results indicated that Ce element had a great impact on the corrosion potential of the alloy tested in 0.5% NaCl solution. Alloying with 0.15% Ce element could make the corrosion potential shift to inert direction and reduce the corrosion current density. An excessive Ce addition could weaken its positive effect on the corrosion resistance of the Ce-containing alloy.


2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Wenzheng Chen ◽  
Wenlong Zhang ◽  
Dongyan Ding ◽  
Daihong Xiao

Microstructural optimization of Al-Li alloys plays a key role in the adjustment of mechanical properties as well as corrosion behavior. In this work, Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn alloy was homogenized at different temperatures and holding times, followed by aging treatment. The microstructure and composition of the homogenized alloys and aged alloys were investigated. There were Al7Cu4Li phase, Al3Li phase, and Al2CuLi phases in the homogenized alloys. The Al7Cu4Li phase was dissolved with an increase in homogenization temperature and holding time. Al2Cu phase and Al2CuLi phase coarsened during the homogenization process. The alloy homogenized at 515 °C for 20 h was subjected to a two-stage aging treatment. Peak-age alloy, which had gone through age treatment at 120 °C for 4 h and 180 °C for 6 h, was mainly composed of α-Al, Al20Cu2Mn3, Al2CuLi, Al2Cu, and Al3Li phases. Tafel polarization of the peak-age alloys revealed the corrosion potential and corrosion current density to be −779 mV and 2.979 μA/cm2, respectively. The over-age alloy had a more positive corrosion potential of −658 mV but presented a higher corrosion current of 6.929 μA/cm2.


2012 ◽  
Vol 487 ◽  
pp. 53-57
Author(s):  
Mei Cao ◽  
Zhong Cheng Guo ◽  
Xiang Lan Xie ◽  
Su Qiong He

Pb-PANI-WC inert anodes were prepared by direct current and pulse electrodeposition of PANI (conductive polyaniline) and WC particles with Pb2+ on the surface of titanium (Ti) substrate. The anodic polarization curves, cyclic voltammetry curves and Tafel polarization curves were measured in the solution of 50 g/L Zn2+, 150 g/L H2SO4 and 35°C, and the kinetic parameters of oxygen evolution, voltammetry charge, corrosion potential and corrosion current density have been obtained. The surface morphologies of the coating were investigated by using scanning electron microscope(SEM).The results show that the inert anodes prepared by pulse electrodeposition possess lower overpotential of oxygen evolution, higher electrocatalytic activity, and better reversibility of electrode reaction and corrosion resistance.


2012 ◽  
Vol 538-541 ◽  
pp. 230-234
Author(s):  
Hui Cheng Yu ◽  
Xiao Xiao Huang ◽  
Yan Yan Han ◽  
Dong Ping Wei

To improve the corrosion resistance of Al alloy, triethylamine (TEN) was added into the sealing solutions. Tafel polarization and electrochemical impedance spectroscopy(EIS) techniques were used to investigate the electrochemical behavior of sealing coatings formed in different concentrations of triethylamine(TEN). Compared with the coatings with D. I. water and the bare aluminum alloy, the polarization curves show that the sealing coatings formed in 5.0 – 7 .0 g.L-1 triethylamine (TEN) solutions have more positive corrosion potential (Ecorr) and pitting corrosion potential (Epit), and lower corrosion current density (icorr). Electrochemical parameters of EIS indicate that the sealing coatings have higher corrosion resistance. The electrochemical test results show the prepared sealing coatings have better corrosion resistance.


2017 ◽  
Vol 3 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Shaik Liyakhath Ahmed ◽  
Sunil Kumar Thamida ◽  
N. Narasaiah

AbstractPolarization data characterize the corrosion behavior of a metal giving a quick estimate of corrosion current density icorr and corrosion potential Ecorr. These two characteristics determine the corrosion rate and position of the metal in galvanic series. The chosen system for the study is steel (SS304) in NaCl solution. In these studies, icorr and Ecorr of Butler-Volmer equation are obtained by fitting the full expression to experimental current vs potential data unlike the graphical method using Tafelslopes. MATLAB optimization tool box is utilized for this purpose. The novel optimization technique is explained for determining Ecorr and icorr


2017 ◽  
Vol 62 (4) ◽  
pp. 2101-2106
Author(s):  
M. Kciuk ◽  
S. Lasok

AbstractThe paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.


2004 ◽  
Vol 1 (2) ◽  
pp. 289-294
Author(s):  
Baghdad Science Journal

The corcosion behoviour of Aluminum bronze in sodium chloride solution has been studied ^tentiostatically at five temperatures in the range 293-313K.The corrosion potential shifted to more negative values with increasing temperature. The corrosion current density increased with increasing temperature. Values of Tal'el slopes and the transfer coefficients indicated hydrogen evolution reaction to occur at the cathode and mainly the dissolution at the anode.Benzotriazole (BTA) had an inhibiting effect ??? the corrosion of the Al-bronze in deaerated NaCl solution at a concentration (1*10'?- IxlO‘1) mol dm'^ over the temperature range 293-313K. Values of the protection efficiency and kinetics parameters were obtained from the corrosion current densities. 'I’he results indicated that corrosion reaction on Al-bronze occurred on surface sites having different energies of activation.


2013 ◽  
Vol 643 ◽  
pp. 33-36
Author(s):  
Wei Ke An ◽  
An Hui Cai ◽  
Guo Jun Zhou ◽  
Yun Luo ◽  
Tie Lin Li ◽  
...  

The corrosion behavior of Cu50Zr40Ti10 (at. %) in HCl and NaCl solutions was investigated. The corrosion current densities icorr in HCl and NaCl solutions increase with increasing Clconcentration when the Cl- concentration is <0.5 molL-1, then continuously increase in the former and decrease in the latter. The icorr is larger in the latter than in the former when the Clconcentration is <0.5 molL-1, while inversely for in 1 molL-1 Cl- solution. The corrosion potential Ecorr decreases with increasing Cl- concentration in HCl. However, the change of the Ecorr vs. the chloride ion concentration in NaCl solution appears down-up-down.


2021 ◽  
Vol 46 (1) ◽  
pp. 1-6
Author(s):  
Dino Woelk ◽  
Norbert Kazamer ◽  
Gabriela Mărginean

The corrosion behaviour of forged and SLM (Selective Laser Melting) processed 316L samples was investigated in a 3.5% NaCl solution at neutral and light acidic pH. The influence of the oxygen concentration in the testing solution on the corrosion resistance of the alloy was also proved. This made it possible to qualitatively evaluate the influence of the additive manufacturing process on the microstructure of the 316L alloy in comparison to that of the forged steel. Therefore, the logarithmic polarisation curves generated during the electrochemical investigations were compared, especially in respect to the corrosion potential respectively corrosion current density. The results showed that the corrosion resistance of the 3D-printed samples was inferior to that of the forged 316L. Instead of the pitting corrosion that often appears during exposure of the forged material to chloride containing media, the SLM processed material exhibited rather an extensive surface attack. The microscopic examination of the samples revealed large differences in porosity between the microstructures obtained by means of the two manufacturing methods, whereby the 3D-printed samples exhibited a larger number of voids.


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