Electrochemical study and experimental simulation of the synergistic effect of a formulation based on Ficus pumila Linn. Leaves extract and zinc sulfate on the XC38 steel corrosion inhibition in NaCl solution

•Mixture of Ficus pumila hydroalcoholic extract (HEFP) and Zn2+ is a novel green corrosion inhibitor.•50 ppm of Zn2+ and 200 ppm of HEFP have the maximum inhibition efficiency (91.3%).•A mixture of quercetin, gallic acid and Zn2+ was used to simulate inhibitive capacity of HEFP + Zn2+ formulation.•The inhibition mechanism involves Zn2+, Fe2+, Fe3+ and some compounds of HEFP.