Corrosion behavior of Aluminium in alkaline-water hyacinth plant extract functionalized solution: An electrochemical and weight loss study

This study examined the extent how aluminium corroded in 0.5 M NaOH (sodium hydroxide) in the presence and absence of powdered water hyacinth plant extract (PWHE) as an inhibitor, at different concentrations of 0.25 g/L, 0.20 g/L, 0.15 g/L, 0.10 g/L, and 0.05 g/L. The corrosion rate of the test metal samples were examined using the weight loss method and electrochemical route. A higher corrosion rate and lower corrosion potential obtained via the weight loss (WL) and electrochemical polarization (EP) route of 0.02563 mmpy (obtained via WL), -1.494 V (EP), and 0.3597 mmpy (EP) was obtained for the control sample. However, at 0.25 g/L of PWHE, the corrosion rate via the WL and EP was 0.003374 mmpy and 0.03356 mmpy, respectively, with a higher corrosion potential of -1.482 V showing a significant reduction in the rate of corrosion.