Abstract
Experimental weight loss and electrochemical measurements were used at ambient and high tempera-tures to evaluate the corrosion inhibition efficacies of diaminodecane functionalized graphene oxide (DAD-GO) and diaminododecane functionalized graphene oxide (DADD-GO) against carbon steel corro-sion in 15.0 % HCl, mimicking an acidizing environment in an oil/gas well. The GO was made from waste graphite and then grafted with the diaminoalkanes (DAD & DADD). The GO and functionalized GOs were described using FTIR, Raman, TEM, and TGA. Concentration and temperature effects on the inhibitors' performance were also looked into. The inhibition efficiency increased with concentration at room temperature, reaching a maximum of 84 % for DAD-GO and 78 % for DADD-GO at a concentration of 5 ppm for both. At the temperatures studied, the inhibitors performed well at extremely low concen-trations; however, as the temperature rises, the inhibitor's performance decreases. According to the PDP measurement, the inhibitors function primarily as mixed-type inhibitors. The Langmuir adsorption the-ory was found to be followed by the studied compound. AFM, SEM, EDX, and FTIR characterization of the steel surfaces revealed that the functionalized GOs molecules adsorbed on the steel to create a protective layer that insulated the steel from aggressive acid assault after the immersion time (24 h) in the inhibited solutions. DFT calculations were utilized to determine the relative stability of functionalized GOs to GO and to learn more about the inhibitor molecules' interactions with the steel surface. The DFT cal-culations corroborated the experimental findings. This study is important in tackling two significant envi-ronmental concerns: corrosion and waste management because GO is manufactured from waste graphite.(c) 2022 Elsevier Inc. All rights reserved.