Ficus racemosa leaf extract for inhibiting steel corrosion in a hydrochloric acid medium

•Ficus racemosa leaf extract is a green inhibitor for steel corrosion in acidic solution.•The corrosion of steel is probably retarded via the formation of a protective film.•A good thermal stability of the adsorbent layer as well as an electron abundance of the FRLE’s species.•A much more compact of the solid protective layer that could hinder the electrochemical corrosion.