UV-assisted isomerization studies of active compounds in bush tea (Athrixia phylicoides) leaf extracts and investigations of their potential to inhibit acid corrosion of mild steel and zinc

Abstract

Corrosion of metals can be controlled by using corrosion inhibitors. Plant metabolites undergo geometrical isomerization under the influence of UV light radiation. The use of corrosion inhibitors is one of the useful methods to reduce or decrease corrosion on metals. While synthetic inhibitors are useful in preventing the corrosion of metals, they can sometimes be harmful and costly. There is an alternative solution in the form of green inhibitors, which can offer the same level of protection at an affordable price. Inhibitors of corrosion are applied to the environment and the metal they protect against deterioration. Considering this information, it is necessary to examine different metals exposed to an acidic environment in the presence and absence of inhibitors. The impact of UV light radiation on bush tea (A. phylicoides) plant extract was investigated for zinc, and mild steel corrosion exposed to 1.5 M hydrochloric and sulphuric acids at 303-333K. This study employs liquid chromatography-mass spectrometry (LC-MS) to investigate the geometric isomerization of compounds within plant extracts, aiming to identify and quantify different isomers and understand the conditions influencing their stability and transformation. Gravimetric analysis (GA), Electrochemical Impedance Spectroscopy (EIS), and Potentiodynamic Polarization (PDP) were used to study corrosion inhibition, Fourier Transform Infrared Spectroscopy (FTIR) was used to analyze functional groups in the presence and absence of corrosion inhibitors. Contact angle or wettability studies (CA / WS) have been conducted to assess the hydrophobicity or hydrophilicity of the surface. Scanning Electron Microscopy (SEM) and computational studies were employed to gain a deeper understanding of the surface morphology and interactions between the A. phylicoides plant extracts and the metal surface. LC-MS chromatograph shows that the extract undergoes geometric isomerization. The GA, EIS, and PDP tests showed that the extracts were able to reduce the amount of corrosion that occurred on the metal surface. FTIR tests confirmed that the extracts were able to form a protective layer on the metal surfaces, which inhibited the corrosion process. The SEM and computational studies provided additional evidence that the extracts were able to reduce the corrosion rate by forming a protective layer on the metal surfaces. The results of the study showed that the extracts had a strong adhesive capacity and were able to form a stable protective layer on the metal surfaces. This layer was able to resist the corrosive action of the environment and prevent further corrosion. The study also showed that the extracts had good stability and were able to remain intact on the metal surface for a long time.