Utilization of watermelon rind extract as a green corrosion inhibitor for mild steel in acidic media

•Watermelon rind extracts inhibited mild steel corrosion in HCl and H2SO4 solutions.•The adsorption of WMRE follow Temkin isotherm model.•The extracts behave as a mixed-type inhibitor in both media.•Results from all the methods are in reasonable agreement.•WMRE is a better inhibitor in HCl than in H2SO4 solution. Electrochemical techniques were used to investigate the efficacy of watermelon rind extract (WMRE) as corrosion inhibitor for mild steel in HCl and H2SO4 solutions. The inhibition efficiency increased as the concentration of the extract increases. Potentiodynamic polarization results indicate that WMRE act as a mixed-type inhibitor. The values of effective capacitance obtained by utilizing the impedance parameters in both acidic media are in the range of double layer capacitance. Corrosion inhibition effect of WMRE can be attributed to the adsorption of constituents of WMRE onto the mild steel surface which can be approximated by Temkin adsorption isotherm model.