An exploration of the ultrasonication effect on interlayer spacing and mass transfer in Ti3C2 MXene for enhanced CO2 adsorption

MXenes, particularly Ti 3 C 2 , are promising materials for CO 2 adsorption due to their high surface area, tunable interlayer spacing, and surface functionalization potential. This study investigates the effect of ultrasound-assisted synthesis of Ti 3 C 2 MXene on CO 2 adsorption, which is enhanced through increased interlayer separation and improved mass transfer coefficients. Ultrasonication promotes defect formation and delamination, improving the material’s adsorption efficiency. The adsorption process was analyzed using five isotherm models; among them, the Sips model provided the best fitting R 2 of 0.9925, indicating a combination of monolayer and multilayer adsorption. Adsorption kinetics were evaluated using four models, with the Elovich model showing the highest correlation R 2 of 0.9936, suggesting that physisorption plays a dominant role. Thermodynamic analysis for MXene Ti 3 C 2 treated by ultrasonic confirmed that the CO 2 adsorption process is exothermic and spontaneous with a ΔH of − 8.986 kJ/mol with a negative entropy of − 0.003 kJ/mol·K and ∆G of − 8.241 kJ/mol, indicating structured CO 2 binding and enhanced adsorption stability. Ultrasonication significantly improved adsorption performance by increasing surface area and active site availability, leading to a maximum CO 2 adsorption capacity of 9.990 mmol/g at 25 °C and 9 bar. Additionally, mass transfer analysis revealed rapid initial CO 2 uptake, stabilizing at equilibrium. The enhanced CO 2 uptake and the stability and recyclability of Ti 3 C 2 MXene demonstrate its potential for scalable CO 2 capture applications. Further optimization of synthesis conditions and functionalization strategies could enhance performance, selectivity, and long-term applicability in industrial CO 2 separation and storage systems.