Enhancement of corrosion inhibition of mild steel in acidic media by green-synthesized nano-manganese oxide

In this study, extracts of withered flower petals such as rose petal (RP) and lotus petal (LP) were used as sources for natural antioxidants, namely anthocyanins, flavonols, phenolic compounds, and pectin to prepare nano-manganese oxide through the ultrasonic wave assisted green synthesis method, which is cost-effective and eco-friendly. The prepared nano-manganese oxides were used for enhancement of corrosion inhibition behavior of mild steel (MS) in acid medium (1 M HCl). The structural properties of the prepared nano samples were studied using X-ray powder diffraction studies (XRD). Functional groups and thermal behaviour of the prepared metal oxides were tested through Fourier transform infrared spectra (FTIR) and thermogravimetric (TG) analysis. Transmission electron microscope (TEM) showed the nanosized structure of the prepared manganese oxide. The specific surface areas were found to be 27.914 and 39.438 m(2)g(-1) for the sample prepared from the RP and LPs extract, respectively by BET surface area analysis. Improved electrochemical properties were observed for LPM and the corrosion inhibition efficiency of LPM (72.63%) and RPM (51.50%) was higher compared to the bare MS plate under 1 M HCl medium. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, extracts of withered flower petals were used to prepare nano-manganese oxide, which showed improved corrosion inhibition efficiency in 1 M HCl medium. Various structural and performance tests were conducted to study the prepared nano samples, demonstrating the potential for effective corrosion protection.