2025-03-06http://itsupport.cu.edu.ng:4000/handle/123456789/29802The corrosion inhibition effect of extracts of kola plant (cola acuminata) and green tea (camellia sinensis) in mixed form on the protection of mild steel specimens immersed in sulphuric acid solution was studied at ambient temperature by gravimetric and potential monitoring methods. The electrode potential monitoring was performed using a digital voltmeter and a saturated calomel electrode (SCE) as the reference electrode. Extracts of kola plant and green tea in different concentrations and combinations were used as ‘green’ inhibitors. There was significant reduction in the weight loss and in the corrosion rate of the test samples, particularly at the added extracts concentration of 100% and also at the concentrations of 50 and 25%. Some very good inhibitor efficiency values were obtained which suggested good corrosion inhibition performance of the added extracts at the concentrations used. Potential measurement values recorded showed a reduction in active corrosion reactions for all the combinations of the extracts. This behavior was attributed to the protective film provided on the steel’s surface by the complex chemical constituents of the plants extracts. The best corrosion inhibition performance for mild steel was obtained using the combined extracts of kola leaf and green tea at100% concentration. The combination of kola leaf, kola nut and green tea at the same concentration was also effective in corrosion inhibition performanceapplication/pdfTJ Mechanical engineering and machineryArticle