N-doped clay-like Ti3C2Tx MXene/TiO2 spherical composites for methanol sensing in exhaled breath: A theoretical feasibility

It is of great significance to detect methanol in human exhaled breath since it may cause neurological disorders. In this study, N-doped Ti 3 C 2 T x MXene was synthesized by annealing and nitrogen doping in clay-like Ti 3 C 2 T x MXene. Then, TiO 2 nanospheres was generated in situ on the surface of N-doped Ti 3 C 2 T x MXene to provide adsorption and reaction sites for methanol. Based on the synergistic effects of electronic properties and gas adsorption, the N-Ti 3 C 2 T x MXene/TiO 2 exhibits high responsiveness and excellent selectivity to methanol at room temperature. Moreover, the detection limit is 0.1194 ppm. In addition, the adsorption and oxidation process of methanol on the N-Ti 3 C 2 T x MXene/TiO 2 was explored by in situ infrared spectra testing to reveal that the oxygen vacancy on the surface of N-Ti 3 C 2 T x MXene/TiO 2 plays an important role in the selective detection of methanol. This experiment provides a feasible solution for the detection of methanol gas in exhaled breath at room temperature.