Prosopis juliflora Plant Extract as Potential Corrosion Inhibitor for Low-Carbon Steel in 1 M HCl Solution

Abstract

Herein, Prosopis juliflora (PJF) plant extract was assessed as a low-cost, green and efficient corrosion inhibitor for low-carbon steel (LCS) in 1 M hydrochloric acid solution using mass loss, gasometric, electrochemical impedance spectroscopy, potentiodynamic polarization, electrochemical frequency modulation methods as well as surface studies by scanning electronic microscope (SEM) and atomic force microscope (AFM). Increasing (PJF) extract concentration increases the charge transfer resistance (R ct) and decreases the double-layer capacitance (C dl) as a result of the adsorption of PJF extract on the LCS surface. The polarization results showed the mixed-type inhibition behavior of the studied extract with inhibition efficiency (%IE) of 90.7% achieved with the addition of 300 ppm of PJF. The adsorption isotherm model of PJF extract on LCS surface followed Temkin adsorption isotherm in HCl solution. The inhibition mechanism of PJF was explained according to the increase in the %IE with temperature and the activation parameters which suggested significant chemisorption of the PJF extract on the LCS surface. The AFM and SEM studies confirmed the formation of protective layer of PJF extract on LCS surface. Results obtained by different techniques showed good agreement which confirm the potential use of PJF extract as corrosion inhibitor for LCS in acidic media.