Evaluation of Antioxidant and Anticorrosive Activities of <i>Ceriops tagal</i> Plant Extract

Mangroves are plants known for their various medicinal and economical values, and therefore are widely investigated for their phytochemical, antioxidant, antidiarrheal, and antimicrobial activities. In the present study, we analyze the antioxidant and anticorrosive properties of Ceriops tagal (C. tagal), a tropical and subtropical mangrove plant of the Rhizophoraceae family. The total phenolic content (TPC) and total flavonoid content (TFC) were found to be 101.52 and 35.71 mg/g, respectively. The extract (100 µg/mL) exhibited 83.88, 85, and 87% antioxidant property against 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide, and hydrogen peroxide free radicals. In addition, 600 ppm of C. tagal extract showed 95% corrosion inhibition against 1 M HCl attack on mild steel at 303 ± 1 K, which declined over other concentrations and temperatures, where AAS produced 82% inhibition at 600 ppm. UV-visible spectroscopy analysis revealed the formation of an inhibitor metal complex. The elemental analysis provided the presence of 84.21, 9.01, and 6.37% of Fe, O, and C, respectively, in inhibited mild steel, whereas the same were 71.54, 22.1, and 4.34%, respectively, in uninhibited specimen, stressing the presence of protective film on the metal surface. Scanning electron microscopy (SEM) also showed some noteworthy changes in both uninhibited and inhibited mild steel, making C. tagal plant a better alternative than any other synthetic inhibitors. Further, the atomic force microscopy (AFM) surface topography analysis showed that 600 ppm of C. tagal extract significantly diminished corrosion on the surface of mild steel