Corrosion inhibition of copper by 2,5-dimercapto-1,3,4-thiadiazole monolayer in acidic solution

Research highlights: → 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) monolayer was self-assembled on copper surface. → DMTD was assembled on copper surface in a closely parallel manner. → DMTD monolayer is a mixed inhibitor for copper in 0.5 M HCl. - Abstract: 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) monolayer was self-assembled on the fresh copper surface to form protective monolayer against copper corrosion in acidic solution. Its corrosion inhibition was investigated in 0.5 M HCl by cyclic voltammetry, potentiodynamic polarization and electrochemical impedance spectroscopy methods. The results revealed that the DMTD monolayer inhibited the copper corrosion effectively with the optimum self-assembly time of 10 h and the optimum self-assembly concentration of 7.5 mM. Surface observation was performed using scanning electron microscope, contact angle goniometer and Fourier transform infrared spectrometer. The molecular simulation has been used to simulate the adsorption model of DMTD molecule on Cu(1 1 1) surface.