Arabian Journal of Chemical and Environmental Research Vol. 08 Issue 2 (2021) 336–354 ISSN : 2458-6544 © 2021 ; www.mocedes.org. All rights reserved. Performance of 5-amino-1,3,4-thiadiazole-2-thiol as corrosion inhibitor for aluminium in dilute hydrochloric acid medium U. Yunusa 1* , A. I. Kubo 2 , G. N. Bello 3 , and A. Shehu 4 1 Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, Bayero University, Kano, Nigeria. 2 Department of Pure and Applied Chemistry, Adamawa State University, Mubi, Nigeria. 3 Chemical Division, Industrial Development Department, FMITI, PMB 88, Garki 1, Abuja, Nigeria. 4 Department of General Studies, Federal College of Agricultural Produce Technology, Kano, Nigeria. Received 10 June 2021, Revised 23 Oct 2021, Accepted 23 Oct 2021 Abstract The inhibition performance of 5-amino-1,3,4-thiadiazole-2-thiol (5-ATT) on aluminium corrosion in acidic medium was investigated using experimental and theoretical approach. The weight loss measurements demonstrated that the inhibition efficiency increased with an increase in concentration of 5-ATT but decreased at elevated temperatures. The inhibitor molecule exhibited the highest inhibition efficiency of 94.28 % at 2.0 mM for T = 308 K. The adsorption of the 5-ATT on aluminium surface in acid solution was found to obey the Langmuir isotherm and the value of ∆G #$% & suggest a combination of both physisorption and chemisorption mechanisms. Scanning electron microscopy analysis demonstrated the adsorption of 5-ATT on the aluminium surface which justified the observed anticorrosion activity. Besides, the correlation between inhibition performance and the electronic structure parameters of the inhibitor was theoretically elucidated via quantum chemical calculations. Molecular dynamics simulations were engaged to provide insights into the mechanism of interaction between the inhibitor and the aluminium surface. The theoretical outcomes highlighted the ability of the 5-ATT to adsorbed favourably on the Al (1 1 0) surface in parallel orientation. Keywords: 1,3,4-thiadiazole, Aluminium, Corrosion inhibition, Quantum chemical calculations, MD simulations. *Corresponding author. E-mail address: umaryunusa93@gmail.com