Experimental, DFT and MD evaluation of Nandina domestica Thunb. extract as green inhibitor for carbon steel corrosion in acidic medium

Abstract

Plant extracts with the advantages of environment–friendly, renewable and rich resources, can be used as promising corrosion inhibitors in pickling or descaling processes. In this study, the inhibition performance and inhibition mechanism of Nandina domestica Thunb. extract (NDTE) for carbon steel in HCl solution was evaluated by electrochemical experiments, component analysis, surface characterization and theoretical calculations. The results show that NDTE can significantly inhibit the corrosion of carbon steel in HCl solution, and its maximum corrosion inhibition efficiency can reach 96.0% at 298 K. In addition, NDTE still exhibited excellent corrosion inhibition performance at 328 K, with a 93.5% corrosion inhibition efficiency. The Tafel results indicate that NDTE is a mixed–type inhibitor, and its adsorption on the surface of carbon steel conforms to the Langmuir isotherm model. Surface characterization shows that NDTE has attractive inhibition performance for carbon steel over a wide temperature range. In addition, the inhibition mechanism of NDTE were studied by quantum chemical calculations and molecular dynamics simulation. This work provides a useful insight into the anti–corrosion of carbon steel during industrial pickling or descaling processes.