Combretum bracteosum extracts as eco-friendly corrosion inhibitor for mild steel in acidic medium

Purpose: The purpose of this paper is to investigate the corrosion inhibitive properties of extracts from mature leaves of Combretum bracteosum for the corrosion of mild steel in H2SO4. Design/methodology/approach: Acid extracts from mature leaves of Combretum bracteosum are used as mild steel corrosion inhibitors in various tests at 30-60°C. The gravimetric and hydrogen evolution (via the gasometric assembly) measurements are conducted. Findings: The mature leaves of Combretum bracteosum extracts inhibit the corrosion of mild steel in H2SO 4 to reasonable extent. Inhibition efficiency increases with the plant extracts concentration and decreases with temperature. Phenomenon of physical adsorption is proposed as the mechanism of inhibition and the Frumkin adsorption isotherm obeyed. Kinetic parameters for the dissolution of mild steel in H2SO4 solutions are calculated. Practical implications: Mature leaves extract from Combretum bracteosum can be used in chemical cleaning and pickling processes. Originality/value: The research provides new information on the possible use of the leaves of Combretum bracteosum as an eco-friendly corrosion inhibitor of mild steel in H 2SO4. © Emerald Group Publishing Limited.