Synergistic mixture of Capsicum annuum fruit extract/KI as an efficient inhibitor for the corrosion of P110 steel in 15 % HCl solution under hydrodynamic condition

The primary goal of this study is to discover a sustainable, renewable, and ecologically friendly anticorrosive inhibitor. Anticorrosion analysis of Capsicum annuum fruit extract (CAFE) was examined under hydrodynamic solution at 1500 rpm in 15 % on P110 steel. Results of the assessment showed that CAFE inhibits the corrosion of P110 steel and the rate of corrosion is significantly reduced on increasing its dosing amount. CAFE exhibits the maximum anticorrosive efficiency to 89.5 % (CAFE/800 mg/L) and 92.2 % (CAFE + KI/600 mg/L). The CAFE shows the chemical nature of inhibition effect. The maximum and minimum charge transfer resistance (R_ct) and double layer capacitance (C_dl) are 239.5 Ω cm⁻¹ and 27 μF/cm² with the addition of CAFE indicate the corrosion inhibition mitigation. The corrosion mitigation is caused by the adsorption of CAFE molecules on P110 steel surface via Temkin isotherm with chemical mechanism adsorption. The metal surface appearance was visualized via scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photo-electron spectroscopy (XPS). The interaction among the most active constituent i.e., Capsaicin (RCM) sulfate reducing bacteria (SRB) protein was examined by molecular docking. Additionally, an atomic level study of RCM was performed using DFT and MD.