Tracking the thermal dynamics of Ti3C2Tx MXene with XPS and two-dimensional correlation spectroscopy

MXenes are a class of two-dimensional materials with potential applications in the fields such as thermal management and high-temperature materials. In this study, the transitions of Ti3C2Tx MXene are investigated during thermal annealing via x-ray photoelectron spectroscopy and two-dimensional correlation spectroscopy. The thermal evolution of MXene samples occurs as two distinct processes in different temperature regions: process I (from 25 to 500 ?) and process II (from 500 to 777 ?). In process I, the terminal groups of MXene are reduced, and fluorine (-F) terminal groups are released. Four different pathways are identified with C-Ti-O and C-C as probable final products. In process II, the reaction resulting in the removal of -F species and decomposition of the Ti3C2 region in the MXene is observed. These results provide insight into the thermal decomposition behavior of Ti3C2Tx MXene, which can assist in the design of MXene-based materials with specific functionalities.