Photoelectrochemical characteristics of oxide layers on copper-nickel alloys

Photoelectrochemical Study of Corrosion Resisting Property of Cupronickel B10 in Simulated Cooling Water

“…12 Figure 2a reveals the i ph ～φ curves for cupronickel B10 electrodes in simulated cooling water containing chloride at various concentrations for 2 h. The B10 electrodes all show cathodic photocurrent on the positive scan, i ph decreases with increasing chloride concentration and tends to zero at about 0 V, so the corrosion resisting property of the B10 electrodes gets worse as the Cl -concentration increases. [2][3][4][5][6][7][8] On the negative scan, the B10 electrodes all show cathodic photocurrents at potentials more negative than -0.1 V, and have cathodic i ph,max at about -0.55 V. The cathodic i ph,max decreases with increasing chloride concentration. The decrease of i ph,max might be related to the doping of Cu 2 O film by Cl -ions.…”

“…A photocurrent was not observed from CuO on the Cu electrode because of its low resistivity and high recombination rate. 6,13 On the reverse potential scan, i ph gradually increases as CuO was reduced to Cu 2 O, the value of i ph reached the maximum at -0.50 V, about 52 nA•cm -2 , and then decreased after -0.50 V as Cu 2 O was gradually reduced to Cu. At potentials more negative than -0.70 V, i ph was close to zero as the electrode was nearly reduced to the metallic state.…”

“…Because the corrosion resistance of copper-nickel alloys is much bigger than that of brass in seawater and NH 3 -containing solution, copper-nickel alloy tubes are often employed for the air removal section of condensers in some power plants. There exists a passive film on the surface of copper-nickel alloy, showing a semiconductive property, which could be studied by using a photoelectrochemical method.…”

“…Some important information can not be obtained by usual electrochemical methods and surface analysis techniques, but can be got by photoelectrochemical method. [1][2][3][4][5][6][7] Not only can we study the corrosion and passivation behavior for metal by a photoelectrochemical method, but also the inhibition mechanism for metal corrosion. We have published some papers related to the corrosion inhibition of copper and copper alloys.…”

Photogalvanic effect in aqueous Methylene blue nickel mesh systems: Conversion of light into electricity

“…It is also a light sensitive oxide (Midwest Research Institute, 1983). It was shown for nickel that the semiconductive oxide, NiO, with a band gap of 3.4 eV is the main oxide grown in most electrochemical solutions (Kamkin et al, 1999). Mesh electrodes also allowed the illumination and excitation of MB blue molecules that would practically be blocked by the electrode if plate electrodes were installed instead.…”