Adsorption and corrosion inhibition of phytic acid calcium on the copper surface in 3 wt% NaCl solution

• PAC film effectively inhibits the copper from corrosion in 3 wt% NaCl solution.
• The adsorption of PAC is successfully described by the Langmuir adsorption isotherm.
• Value of ΔGads0 reveals the film formation on the copper surface via chemisorbed fashion.
• Raman spectrum elucidates PAC film at the copper surface through PO groups.

The adsorption and corrosion protection effect of phytic acid calcium (PAC) film on the copper surface in 3 wt% NaCl solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Raman spectroscopy. Polarization curves indicate that PAC is a mixed inhibitor, affecting both cathodic and anodic corrosion currents. The inhibition efficiency of PAC film reached 92.53% at an optimized condition. Adsorption of PAC molecules on the surface followed Langmuir adsorption isotherm and the standard Gibbs energy of −37.32 kJ mol−1 indicated a chemisorptive way. Raman studies suggested that PAC molecule chemically anchored at the surface via PO groups.