Effect of doping on the sensitivity of Ti2CO2 toward NO: A DFT study

Detecting harmful gasses is important to the public health, and MXenes are promising candidates as effective sensors. The adsorption stability, electronic and magnetic properties of NO molecule on modified Ti2CO2 was explored using density functional theory (DFT), including perfect, vacancy-defected, transition-metal (TM) doped Ti2CO2 substrates. The results indicated that TM-doping was more effective to improve the activity of Ti2CO2 than the introducing of O-vacancy. The large adsorption energies, short interaction distance, and high charge transfer suggested the adsorption of NO on doped Ti2CO2 were chemisorption. Hybridization between the 3d-orbital of TM-dopants and NO molecule play a key role to enhance the stability of NO molecule. It is hoped that these results could provide novel information to design MXene-based sensors.