Electrochemical investigation of the corrosion inhibition mechanism of Tectona grandis leaf extract for SS304 stainless steel in hydrochloric acid

Abstract

The use of Tectona grandis leaf extract as a green corrosion inhibitor for stainless steel 304 (SS304) in 2 m hydrochloric acid was investigated using electrochemical techniques. Potentiodynamic polarization studies with different inhibitor concentrations showed that the inhibitor is of mixed type, which works by affecting both cathodic and anodic reactions. Adsorption analysis using the potentiodynamic polarization and electrochemical impedance spectroscopy runs result in standard free energy of adsorption values between −20 kJ mol−1 and −40 kJ mol−1, indicating a comprehensive adsorption, which is a mixture of both physisorption and chemisorptions processes. Fourier transform infrared spectroscopy studies show the appearance of new peaks and shift in peak positions at some locations with the use of an inhibitor, which indicates the interaction between the inhibitor molecules and metal surface. Contact angle analysis indicates the formation of hydrophobic film on the metal surface.

New Electrospun Polystyrene/Al2O3 Nanocomposite Superhydrophobic Coatings; Synthesis, Characterization, and Application

“…The capacitances are substituted by constant phase elements (C dl1 and C dl2 ) to give a more precise fit to the experimental outcomes. The exponent (0 ≤ n ≤ 1) represents deviation from an ideal dielectric behavior; if n = 0, it shows an ideal resistor, and if n = 1, it acts as an ideal capacitor [57][58][59][60][61][62][63][64]. It is noticed that the R po and R ct significantly increase as the WCA increases.…”

The anti-corrosion behaviour of Satureja montana L. extract on iron in NaCl solution

“…However, bc values change significantly so both extracts behave like cathodic inhibitors. An inhibitor can be referred as cathodic or anodic if the displacement in corrosion potential is more than 85 mV with respect to Ecorr of the blank [17,30]. In our study, the displacement in Ecorr value was less than 85 mV and this indicates that both extracts can be classified as mixed-type inhibitor which is predominantly cathodic.…”

Theoretical, chemical, and electrochemical studies of Equisetum arvense extract as an impactful inhibitor of steel corrosion in 2 M HCl electrolyte

“…Table 7 reports that EAAP extract has a better inhibition efficacy for steel than other extract inhibitors in 2 M HCl solution 67 – 73 .…”

“… Extract Optimum con. of extract Corrosive solutions Maximum efficiency, % References Aizoon canariense 250 ppm 2 M HCl 82.6 67 Olive leaf extract 900 ppm 2 M HCl 91.0 68 Conyza bonariensis 100 ppm 2 M HCl 93.3 69 Rosmarinus officinalis 200 ppm 2 M HCl 89.18 70 Eggplant Peel 1000 ppm 2 M HCl 84.0 71 Baphia nitida leaves 100 ppm 2 M HCl 93.0 72 Tectona grandis leaf 1000 ppm 2 M HCl 71.7 73 Equisetum arvense 300 ppm 2 M HCl 97.4 This work …”