In-Depth Insight into Corrosion Inhibition Performance
of Sweet Potato Leaf Extract as a Green and Efficient Inhibitor for
6N01 Al Alloy in the Seawater: Experimental and Theoretical Perspectives
posted on 2024-04-23, 08:34authored byHong Tang, Chengliang Zhou, Ji Li, Wentao Xiong, Bo Chen, Jie Peng, Xinyu Pan, Meng Guo, Zhiyi Xiao, Hong Dai, Xiaohu Luo, Yali Liu
Corrosion protection of metal has
become an important and urgent
topic, which requires the development of an inexpensive, environmentally
friendly, and highly efficient corrosion inhibitor. Herein, a sweet
potato leaf extract (SPL) was obtained by a simple water-based extraction
method and then as a green corrosion inhibitor for 6N01 Al alloy in
the seawater was well investigated by the weight loss method and various
electrochemical tests. Fourier transform infrared (FT-IR) and ultraviolet–visible
(UV–vis) spectroscopies were carried out to investigate the
compositions of SPL. The findings from the potentiodynamic polarization
(PDP) curves suggest that SPL functions as a typical mixed-type corrosion
inhibitor. Notably, the maximum corrosion inhibition efficiency reaches
94.6% following a 36 h immersion period at 25 °C. The adsorption
behavior of SPL on the Al alloy surface belongs to the Langmuir adsorption
isotherm. The Gibbs free energy value illustrates that the adsorption
of SPL contains both physisorption and chemisorption. Scanning electron
microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) indicate
that SPL is firmly attached to the Al alloy surface by making a protective
layer, which can effectively inhibit the corrosion of the Al alloy
in the seawater. Furthermore, quantum chemical calculations were applied
to validate the chemical adsorption and elucidate the relationship
between the electronic structure of the active components in SPL and
their effectiveness in corrosion inhibition.