Superior Selectivity and Sensitivity of C3N Sensor in Probing Toxic Gases NO2 and SO2

The adsorption of gas molecules, such as N
₂
, O2, CO
₂
, H2O, CO, NO, NO
₂
, H2S, NH
₃
, and SO
₂
on monolayer C
₃
N has been investigated by means of first-principles and non-equilibrium Green's function calculations. We show that monolayer C
₃
N is preferable for the NO
₂
and SO
₂
molecules with suitable adsorption strength and apparent charge transfers. Moreover, the I-V characteristics of C
₃
N show clear variations after the adsorption of NO
₂
and SO
₂
. Such sensitivity and selectivity to NO
₂
and SO
₂
molecules make C
₃
N a promising candidate for highly sensitive gas sensor.