Bauhinia tomentosa Leaves Extract as Green Corrosion Inhibitor for Mild Steel in 1M HCl Medium

Bauhinia tomentosa leaves extract (BTLE) as a corrosion inhibitor in 1M HCl was investigated by using weight-loss method and electrochemical techniques. The inhibition efficiency of BTLE was found to increase with increasing concentration. The effect of temperature on the corrosion inhibition of mild steel in the temperature range of 308–333 K was studied. Polarization measurements revealed that the BTLE acted as a mixed-type inhibitor. Nyquist plots showed that on increasing the BTLE concentration, the charge-transfer resistance increased and double-layer capacitance decreased. The adsorption of BTLE on mild steel obeyed the Langmuir adsorption isotherm. The maximum inhibition efficiency was found (93.47% in HCl) at 308 K in the presence of 700 ppm of BTLE. Mechanism of corrosion inhibition of BTLE on mild steel is explored with the help of FT-IR, UV, SEM and AFM techniques. © 2017, Springer International Publishing Switzerland.