Anticorrosion properties of ionic liquid functionalized graphene oxide epoxy composite coating on the carbon steel for CCUS environment

The adoption of CO ₂ capture, utilization, and storage (CCUS) technology is increasingly prevalent, driven by the global initiative to conserve energy and reduce emissions. Nevertheless, CCUS has the potential to induce corrosion in equipment, particularly in high-pressure environments containing CO ₂ . Therefore, anti-corrosion protection is necessary for the metal utilized for CO ₂ production and storage equipment. Herein, an ionic liquid (Triethylsulfonium bis-trifluoromethylsulfonyl-imide) was used to functionalize graphene oxide (prepared via improved Hummers method). FESEM, TEM, and XPS confirmed ionic liquids (IL) were successfully attached to the GO lattice. Afterwards, 0.5 wt% and 1 wt% IL-GO composites were separately incorporated into the epoxy and coated on the carbon steel substrate with a thickness of 50 ± 2 µm. The surface examinations demonstrated a consistent distribution of the ILGO composite in the epoxy matrix and achieved a uniform surface. Anti-corrosive property of 0.5 wt% and 1 wt% IL-GO/epoxy coatings was evaluated using electrochemical tests such as potentiodynamic polarisation, and electrochemical impedance spectroscopy (EIS) after immersion in the CO ₂ (1.5 MPa) and 3.5 wt% NaCl system. After 48 h of immersion in a corrosion environment (CO ₂ -NaCl), the protection efficiency of 0.5 wt% and 1 wt% IL-GO/epoxy coatings are 86.41 ± 0.55 and 92.59 ± 0.83%, respectively. The findings of this study demonstrated that the ILGO composite reinforced epoxy coating exhibited exceptional corrosion resistance when exposed to CO ₂ .