This study investigates the sorption properties of Ti3C2Tx MXenes functionalized with –O– and ‒(O/F) groups for the adsorption of oxygen (O2) and water vapor (H2O). The adsorption behavior of these gases on the MXenes surfaces was analyzed by studying the impact of different gas molecule in 4 different positions and calculating the adsorption energy for each configuration. The interaction mechanisms between the gas molecules and the MXenes surface were a key focus. The findings show that –(O/F) functionalization significantly enhances the sorption of H2O and O2, outperforming –O–functionalized MXenes. In particular, the adsorption of H2O on –O– functionalized MXenes is governed by interactions between the oxygen atoms in H2O and the O-p orbitals on the MXenes surface with adsorption energies of –8.45 eV. For –(O/F) functionalized MXenes, both H2O and O2 exhibit stronger interactions with adsorption energies of – 900 and – 880.65 eV due to the oxygen atoms of the gas molecules interacting with the Ti-d orbitals and the O-p orbitals on the Ti3C2(O/F)2 surface. These results provide valuable insights into the adsorption mechanisms of MXenes and demonstrate that functionalisation with –(O/F) groups improves the interaction strength and gas adsorption capacity, making these MXenes promising for gas separation, storage and sensing applications. The detailed analysis of adsorption energies and molecular interactions carried out in the study highlights the potential of MXenes with selected functional groups to achieve improved gas sorption properties. This could lead to the development of more efficient materials for various applications in environmental monitoring and gas management technologies.
Niaz et al. (Mon,) studied this question.