Protection of copper corrosion in 0.5 M NaCl solution by modification of 5-mercapto-3-phenyl-1,3,4-thiadiazole-2-thione potassium self-assembled monolayer

5-Mercapto-3-phenyl-1,3,4-thiadiazole-2-thione potassium (MPTT) self-assembled monolayer (SAM) on copper surface has been investigated by FT-IR and contact angle (CA) and the results showed that MPTT was adsorbed on copper surface and yielded a hydrophobic film. The inhibition effect of MPTT SAM on copper corrosion in 0.5 M NaCl solution was investigated by using electrochemical methods. The protection ability of SAM was found to depend on the MPTT concentration, assembly time and assembly temperature. Adsorption of MPTT on copper surface follows the Langmuir isotherm. The quantum chemical calculations were conducted to correlate the adsorption mechanism with the structure of MPTT molecule.

► 5-Mercapto-3-phenyl-1,3,4-thiadiazole-2-thione potassium (MPTT) SAM is hydrophobic.
► MPTT SAM inhibits corrosion of copper in 0.5 M NaCl solution.
► MPTT concentration, assembly time and temperature affected the inhibition effect.
► Adsorption mode follows the Langmuir adsorption isotherm.
► Adsorption mechanism was interpreted using quantum chemical calculations.