A study of tetrazoles derivatives as corrosion inhibitors of copper in nitric acid

Purpose – To evaluate the effect of some tetrazole compounds as corrosion inhibitors of copper in HNO3 at various temperatures.Design/methodology/approach – 1‐phenyl‐5‐mercapto‐1,2,3,4‐tetrazole (PMT) was selected as the best inhibitor among the tetrazole compounds tested. Gravimetric and electrochemical techniques were conducted.Findings – PMT was an excellent inhibitor for copper in acid. Its efficiency attained 97.5 per cent and decreased slightly with temperature.Research limitations/implications – The inhibition efficiency increased with the concentration of PMT to reach 97.5 per cent at 10−3 M. Good agreement between the various methods explored was observed. Polarisation measurements also showed that PMT acted as a mixed inhibitor.Practical implications – The efficiency of PMT increased with the concentration but decreased with rise of temperature in the 298‐333 K range. As such, PMT could be used in chemical cleaning and pickling processes.Originality/value – The originality of this work was the f...