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.