Alkaloids extract of Alnus nepalensis bark as a green inhibitor for mild steel corrosion in 1 M H2SO4 solution

Urena lobata bark extract (ULBE) was investigated as corrosion inhibitor for mild steel in 0.5 M H2SO4 by phytochemical method, gravimetric and surface morphological studies. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins and other phytochemicals that inhibit corrosion. The result showed that inhibition efficiency increases with concentration of the inhibitor (from 0.2 g-1.0 g) reaching maximum of 83.28% at 303 K and 24 hr immersion time. It also decreases with temperature rise from 303 K to 333 K. The thermodynamic parameters obtained support a physical adsorption mechanism and best fitted to the Langmuir adsorption isotherm. The values of activation energies obtained in the presence of the inhibitor was all higher than that of the blank solution indicating that ULBE inhibitor effectively inhibits mild steel corrosion. The inhibition process followed first order kinetics. Surface morphological studies revealed that the inhibited mild steel coupons have smooth surfaces whereas mild steel immersed in blank solution showed rough and irregular surfaces, hence confirming the inhibition ability of the inhibitor.

show abstract

Acacia catechu Bark Alkaloids as Novel Green Inhibitors for Mild Steel Corrosion in a One Molar Sulphuric Acid Solution

Karki

Bajgai

Khadka

et al. 2022

Electrochem

View full text Add to dashboard Cite

In situ corrosion inhibition in acid cleaning processes by using green inhibitors is at the forefront of corrosion chemistry. Plant extracts, especially alkaloids, are known to be good corrosion inhibitors against mild steel corrosion. In this research, alkaloids extracted from Acacia catechu have been used as green corrosion inhibitors for mild steel corrosion in a 1 M H2SO4 solution. Qualitative chemical tests and FTIR measurements have been performed to confirm the alkaloids in the extract. The inhibition efficiency of the extract has been studied by using weight-loss and potentiodynamic polarization methods. A weight-loss measurement has been adopted for the study of inhibitor’s concentration effect, with a variation employed to measure the inhibition efficiency for time and temperature. The weight-loss measurement revealed a maximum efficiency of 93.96% after 3 h at 28 °C for a 1000 ppm alkaloid solution. The 1000 ppm inhibitor is effective up to a temperature of 48 °C, with 84.39% efficiency. The electrochemical measurement results revealed that the alkaloids act as a mixed type of inhibitor. Inhibition efficiencies of 98.91% and 98.54% in the 1000 ppm inhibitor concentration solution for the as-immersed and immersed conditions, respectively, have been achieved. The adsorption isotherm has indicated the physical adsorption of alkaloids. Further, the spontaneous and endothermic adsorption processes have been indicated by the thermodynamic parameters. The results show that alkaloids extracted from the bark of Acacia catechu can be a promising green inhibitors for mild steel corrosion.

show abstract

Alkaloids extract of Alnus nepalensis bark as a green inhibitor for mild steel corrosion in 1 M H2SO4 solution

Cited by 5 publications

References 12 publications

A critical review of machine learning algorithms in maritime, offshore, and oil & gas corrosion research: A comprehensive analysis of ANN and RF models

A critical review of machine learning algorithms in maritime, offshore, and oil & gas corrosion research: A comprehensive analysis of ANN and RF models

Bark Extract of Urena lobata as Green Corrosion Inhibitor for Mild Steel in Sulphuric Acid Environment

Acacia catechu Bark Alkaloids as Novel Green Inhibitors for Mild Steel Corrosion in a One Molar Sulphuric Acid Solution

Contact Info

Product

Resources

About