Inhibition Effect of 2,4,6-Trimercapto-1,3,5-triazine Self-Assembled Monolayers on Copper Corrosion in NaCl Solution

2,4,6-Trimercapto-1,3,5-triazine (TMTA) was self-assembled on copper surface by a simple method and the resulting self-assembled monolayers (SAMs) were characterized by FTIR and contact angle. It was found that TMTA dissolved in aqueous solution could be adsorbed rapidly on the copper surface and yielded a hydrophilic surface. The inhibition effect of TMTA SAMs on copper corrosion in 0.5 M NaCl solution was investigated through potentiodynamic polarization curves and electrochemical impedance spectroscopy. Results indicated that TMTA SAMs acted as a mixed type corrosion inhibitor with predominant control of cathodic reaction. The inhibition efficiency increased with increasing assembly time but decreased to some extent with increasing concentration of chloride ions. Immersion test revealed the SAMs could keep good stability and durability in 0.5 M NaCl solution. From the experimental and theoretical study, the mechanisms of TMTA SAMs formation and corrosion protection for copper were discussed.