Geometric, Electronic and Optical Properties of Pt-Doped C3N Monolayer Upon NOxAdsorption: A DFT Study

C
₃
N monolayer is reported with comparable and even more desirable sensing behavior upon small gas molecules in comparison to graphene. In this work, we proposed Pt-doped C
₃
N monolayer as a desirable 2D sensing nanomaterials for NO
_x
detection by DFT method. The Pt atom tends to be doped on the
$\text{B}_{C-C}$
site of C
₃
N surface, making little effect on the bandgap but changing the indirect semiconducting property on the other hand. Pt-C
₃
N monolayer behaves more admirable performance upon NO
₂
adsorption than NO, but both systems are identified as chemisorption with
$E_{ad}$
of −2.25 and −1.99 eV, and
$Q_{T}$
of −0.344 and −0.083 e, respectively. The metallic property is determined in both systems given the calculated zero bandgap, which will increase the electrical conductivity of Pt-C
₃
N monolayer largely after adsorption of NO
_x
gases. This is the basic sensing mechanism for Pt-C
₃
N monolayer upon NO
_x
detection. In the meanwhile, the desirable changes of WF and dielectric function in NO
_x
systems verify the potential of Pt-C
₃
N monolayer for NO
_x
detection through field effect transit or optical devices. Our calculations could be meaningful to exploit novel 2D nanomaterial for sensing NO
_x
in order to monitor toxic gases in our environment.