Study of new amphiphiles based on ferrocene containing thioureas as efficient corrosion inhibitors: Gravimetric, electrochemical, SEM and DFT studies

•Three new amphiphiles based on ferrocene containing thiourea were synthesized and characterized.•Surface activity and corrosion inhibition behavior were investigated.•Studied surfactants acted as efficient inhibitors for steel in 1 M HCl.•Inhibitors efficiency is based on their enhanced adsorption properties.•Presence of long alkyl chain, extended conjugation and heteroatoms improved the adsorption properties.