Abstract: The photoelectrochemistry behaviour of coppere lectrode in buffer bor ax solutions (pH 9.2) containing BTA and 5CBTA was comparatively studied by using photoelectrochemistry technique. The inhibition mechanisms of BTA and 5CBTA for copper corrosion are different. The photoresponse for copper electrode in soluti on containing a certain amount of BTA exhibits n type during anodic polarization , the bigger then-ype photoresponse,the better the inhibition of the inhib itor; the photoresponse for copper electrode in solutions containing 5CBTA alwayse xhibitsp-type during anodic polarization,but the photoresponse changes evide nt ly during cathodic polarization,the bigger the maximum cathodic photocurrent,the better the inhibition of the the inhibitor. Inhibitors can be evaluated by φV and Jph at a more negative potential,the more negative the φV and Jph,the better the inhibition. The results from photoelectroche mical technique are in agreement with those from AC impedance technique.
Photoelectrochemical comparison of inhibiting action of BTA and 5CBTA on copper
Abstract:
The photoelectrochemistry behaviour of copper electrode in buffer borax solutions (pH 9.2) containing BTA and 5CBTA was comparatively studied by using photoelectrochemistry technique. The inhibition mechanisms of BTA and 5CBTA for copper corrosion are different. The photoresponse for copper electrode in solution containing a certain amount of BTA exhibits n type during anodic polarization, the bigger the n type photoresponse, the better the inhibition of the inhibitor; the photoresponse for copper electrode in solutions containing 5CBTA always exhibits p type during anodic polarization, but the photoresponse changes evidently during cathodic polarization, the bigger the maximum cathodic photocurrent, the better the inhibition of the the inhibitor. Inhibitors can be evaluated by φ V and J ph at a more negative potential, the more negative the φ V and J ph , the better the inhibition. The results from photoelectrochemical technique are in agreement with those from AC impedance technique.
Fig.1J vs φ (a) and Jph vs φ (b) curves for copper electrode in buffcr-borax solution with different concentration of BTA (Scanning rate: 1 mV/s; modulation frequency: 39 Hz; irradiation wavelength: 420 nm) 1—[BTA]=0; 2—[BTA]=0.1 mg/L; 3—[BTA]=5 mg/L
Fig.2J vs φ (a) and Jph vs φ (b) curves for copper electrode in buffer-borax solution with different concentrations of 5CBTA (Scanning rate: 1 mV/s; modulation frequency: 39 Hz; irradiation wavelength: 420 nm) 1—[5CBTA]=0; 2—[5CBTA]=0.1 mg/L; 3—[5CBTA]=3 mg/L; 4—[5CBTA]=5 mg/L