Nitrogen-Containing Gas Sensing Properties of 2-D Ti(2)N and Its Derivative Nanosheets: Electronic Structures Insight

In this work, the potentials of two-dimensional Ti(2)N and its derivative nanosheets Ti(2)NT(2)(T=O, F, OH) for some harmful nitrogen-containing gas (NCG) adsorption and sensing applications have been unveiled based on the quantum-mechanical Density Functional Theory calculations. It is found that the interactions between pure Ti(2)N and NCGs (including NO, NO(2), and NH(3) in this study) are very strong, in which NO and NO(2) can even be dissociated, and this would poison the substrate of Ti(2)N monolayer and affect the stability of the sensing material. For the monolayer of Ti(2)NT(2)(T=O, F, OH) that is terminated by functional groups on surface, the adsorption energies of NCGs are greatly reduced, and a large amount of charges are transferred to the functional group, which is beneficial to the reversibility of the sensing material. The significant changes in work function imply the good sensitivity of the above mentioned materials. In addition, the fast response time further consolidates the prospect of two-dimensional Ti(2)NT(2) as efficient NCGs’ sensing materials. This theoretical study would supply physical insight into the NCGs’ sensing mechanism of Ti(2)N based nanosheets and help experimentalists to design better 2-D materials for gas adsorption or sensing applications.