Atomic insights into adsorption of thiophenol derivatives as corrosion inhibitors for mild steel in hydrochloric acid solution

Molecular dynamics simulation was used to investigate the inhibitive adsorption of four thiophenol derivatives (namely, 2-aminothiophenol, 4-aminothiophenol, 2,2'-diaminodiphenyl disulphide and 4,4'-diaminodiphenyl disulphide) on Fe(001) surface in 0.1M hydrochloric acid solution. Moreover, their active sites of adsorption were investigated using density functional theory method. The results indicated that corrosion inhibition performance mainly depends on the interaction between polar groups (heteroatom and benzene ring) and metal surface, while good accordance among adsorption strength (binding energy, deformation energy), frontier molecule orbital parameters and experimental inhibition efficiency is observed, and the feasibility of predicting their inhibition performance using these parameters is verified.