Experimental and theoretical investigations of some pyrazolo-pyrimidine derivatives as corrosion inhibitors on copper in sulfuric acid solution

The anticorrosion performance of three pyrazolo-pyrimidine derivatives, namely, 4-amino pyrazolo-pyrimidine (APP), 4-hydroxy pyrazolo-pyrimidine (HPP), and 4-mercapto pyrazolo-pyrimidine (MPP) on copper in 0.5 M H2SO4 solution have been investigated using electrochemical, surface analysis, as well as theoretical techniques. The results indicate that these inhibitors have largely inhibited the corrosion of copper and the inhibition efficiency increased with increasing concentration. Moreover, the inhibitors adsorb on copper surface following Langmuir adsorption isotherm. XPS analysis were performed for describing the bonding characteristics between inhibitors and copper substrate. Furthermore, DFT and molecular dynamics simulation calculations were applied to further explain the anti-corrosion mechanism.