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

Abstract

The corrosion behavior for cupronickel B10 electrode in simulated cooling water has been Studied by using cyclic voltammetry, a photocurrent response method and electrochemical impedance spectroscopy (EIS). The cupronickel electrode shows a p-type photoresponse to positive and negative potential scan, which comes from Cu2O layer on its surface, but its i(ph,max) is less than that in borax buffer solution. The corrosion resisting property of the cupronickel B10 electrode appeared worse with the increase in the concentrations of Cl-, SO42- and S2- ions, as well as with increasing pH. The rise in the temperature may result in a photoresponse changes from p-type to n-type, and the corrosion resisting property fell simultaneously. The results of the EIS measurement agree well with those obtained by a photoelectrochemical method.National Natural Science Foundation of China [20406009]; Shanghai Education Committee [06ZZ67]; Shanghai Committee of Science and Technology [062312045]; Xiamen University [200512]; Key Discipline of Shanghai Education Committee of China [P1304

Electrochemical and photoelectrochemical study of the self‐assembled monolayer phytic acid on cupronickel B30

“…Figure 5(a) shows the Nyquist plots of B30 electrodes in 3%NaCl solutions with different immersion time in 10 2 2 mol/ L phytic acid solution. The Nyquist plots are all semicircular and the chord is the symbol of resistance of film (R f ), the corrosion resisting properties increase as R f increases (Xu and Wan, 2007;Xu and Zhou, 2001). As shown in Figure 5(a), the corresponding chord of the Nyquist plot is longer as the immersion time increases from 0 to 6 h (Curves 1 , 4) in 10 2 2 mol/L phytic acid solution, its R f is larger.…”

“…The cathodic peaks C1 and C2 correspond to the reduction of Cu(OH) 2 and CuO to Cu 2 O and Cu 2 O to Cu, respectively. CuO is a narrow bandgap semiconductor with Eg ¼ 0.60 eV (Xu and Wan, 2007;Zhou and Modestov, 1995;Xu and Zhou, 2001). A photocurrent is not observed from CuO on the B30 electrode because of its lowresistivity and high-recombination rate as well as NiO for its Eg ¼ 2.8 eV.…”

“…To date, the types of molecules studied for SAMs formed on the copper surface are mainly alkanethiols, alkyl thiosulfates, mercaptoalkanols and Schiff bases (Liu and Chen, 2006;Morad, 2000). Additionally, low concentrations of azole compounds have been employed to grow thin films on copper surfaces for anti-corrosion purposes (Xu and Wan, 2007;Yang and Feng, 2004;Zhou and Modestov, 1995;Xu and Zhou, 2001).…”

Composition formulas of Cu-Ni industrial alloy specifications

“…However, in industrial specifications such as those listed in ASTM (American Society for Testing and Materials) standard, common alloy compositions are only a few. In the Cu-rich side, there are for instance C70600 (10 wt.% Ni, corresponding to B10 in Chinese standard (GB)) and C71500 (~30 wt.% Ni, B30 in GB), both possessing superior comprehensive properties, such as corrosion resistance, thermal conductivity, and plasticity [2,3]. They are often used in ships and power station condensers.…”