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

The self-assembled monolayer (SAM) of phytic acid on cupronickel B30 surface of anticorrosion and inhibiting mechanism have been investigated by electrochemical and photocurrent response method. The results indicate that phytic acid is liable to interact with B30 as a result of formation of complexes on B30 surface for antirust and anticorrosion. The SAM changed the structure of the electric-double-layer and made the value of electric-double-layer capacitance decrease obviously. The B30 electrode showed p-type photoresponse, which came from Cu2O layer on its surface. The photoresponse decreases greatly due to the SAM of phytic acid, but the corrosion resisting property is enhanced. It is in good agreement with the result by EIS and polarization curve. Adsorption of phytic acid is found to follow the Langmuir’s adsorption isotherm and the adsorption mechanism is typical of chemisorption.