Biosynthesis of nickel oxide nanocomposite: Experimental and molecular modelling of its carbon steel corrosion protection in acidizing environment and synergistic effect of NaI

The deployment of plant extracts as inhibitors in corrosion protection of carbon steel is widely praised considering their biodegradability, availability and nontoxic attributes. However, their performance as corrosion inhibitors for a wellbore in an unmodified state is limited due to solubility-related issues and thermal degradation in the environments obtainable during oil well acidizing. The present study synthesized a Dillenia suffruticosa leave extract (DSLE)-mediated NiO nanocomposite for a matrix acidizing oil well environment using biosynthesis technique. The biosynthesized DSLE-NiO nanocomposite was intensively characterized using UV–vis, XRD, TEM and SEM/EDX techniques. The corrosion inhibition performance of the synthesized nanocomposite studied by gravimetric and electrochemical characterization (PDP and EIS) revealed that this nanocomposite could moderately inhibit corrosion of C-steel in an oil well acidizing environment up to an average inhibition efficiency (IE) of 65.4 % at an optimum concentration of 1000 ppm. This efficiency was significantly increased by modifying the DSLE-NiO nanocomposite with sodium iodide (NaI) to 95.2 % at the same concentration. The surface assessment using SEM/EDX affirmed that iodide species significantly enhanced the inhibition performance of the DSLE-NiO nanocomposite in corrosion protection of C-steel in the acidizing solution. This investigation promotes the application of carbon steel-made well casing for matrix acidizing oil well operations in the oil and gas industry. •Corrosion inhibition of C-steel in 5 wt% HCl by DSLE-NiO nanocomposite was studied.•The synergistic effect of NaI effect on the nanocomposite was evaluated.•The nanocomposite offered corrosion inhibition efficiency of 63.1 % at 1000 ppm.•NaI synergistically increased the performance of DSLE-NiO nanocomposite to 95.2 %.•This additive reduced corrosion rate from 1.718 mm/yr to 0.083 mm/yr after 24 h