MXene-based aqueous ethanolamine nanosuspension as new class of CO2 absorption media

Abstract

In this study, for the first time, MXene-monoethanolamine (MEA) nanofluid was employed to enhance carbon dioxide (CO₂) absorption capacity. MXene's 2D structure provides a large surface area and tunable surface chemistry, facilitating CO₂ adsorption and improving its overall absorption efficiency. The MXene nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The nanoparticles were then dispersed in an aqueous MEA solution at specified concentrations using ultrasonication. The density and viscosity of the nanofluids were also measured. The effects of MXene incorporation on CO₂ loading were systematically evaluated. Experiments were conducted at 25 °C and 50–150 psi to assess CO₂ absorption under elevated pressure conditions. CO₂ absorption increased with MXene concentration until an optimum of 0.1 vol% was reached. The highest enhancement of approximately 23 % was observed at 150 psi. This improvement is attributed to MXene’s ability to disrupt the gas-liquid interface, reduce bubble coalescence, and increase the effective contact area, thereby enhancing mass transfer efficiency. These findings suggest that MXene-MEA nanofluids could improve industrial CO₂ capture efficiency, paving the way for more effective carbon mitigation strategies.