Nano-Silicate from Paddy Waste as Natural Corrosion Inhibitor

Abstract

The highly advance usage of an agricultural waste of rice husk ash (RHA) from Oryza sativa L. was developed by extracting the nanosilicate contained in RHA as a corrosion inhibitor for carbon steel in 0.5 M NaCl media. The corrosion measurement was studied using weight loss, potentiodynamic polarization, electrochemical impedance spectros- copy (EIS), surface analysis, and adsorption isotherm study. The extracted nanosilicate powder from RHAwas analyzed using Fourier Transform Infrared Spectroscopy (FTIR) to identify the presence of functional groups (SiO2), whereas X-ray diffraction (XRD) to identify the phase of silica from RHA. The particle size of nanosilicate was confirmed by transmission electron microscopy (TEM) and Zetasizer analysis, and the results show particle size of nanosilicate in the range of 5–10 nm. The maximum inhibition efficiency (IE%) is up to 88% in NaCl media. On the other hand, the inhibitor adsorption proper- ties follow Temkin isotherm with mixed type of inhibition properties. Surface analysis on specimen that was treated with nanosilicate was smoother with fewer pits and pores than untreated specimen. In future perspectives, nanosilicate from RHA has a promising advantages and imminent applications for industries revolving with composites, bio- medicine, and many more.