Phytic acid adsorption on the copper surface: Observation of electrochemistry and Raman spectroscopy

The adsorption of phytic acid (PA) on copper was investigated using electrochemical impedance spectroscopy (EIS), electrochemical polarization measurement and surface-enhanced Raman scattering (SERS) spectroscopy. Electrochemical results indicated that inhibition efficiency of PA film for copper from corrosion in 3 wt% NaCl solution was beyond 80% at an optimum self-assembly concentration of 0.1 mM for 6 h. Electrochemical polarization indicated that PA functioned as a cathodic inhibitor. In addition, Raman studies showed that PA adsorbed on the copper surface formed via P-O groups. Finally, the value of Delta G(ads) (-39.96 kJ mol(-1)) was close to -40 kJ mol(-1), suggesting that the adsorption of PA on the copper surface was the chemical adsorption. (C) 2013 Elsevier B. V. All rights reserved.