Geometric, electronic and optical properties of Pt-doped C3N monolayer upon NOx adsorption: a DFT study

C3N 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 C3N 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 C3N surface, making little effect on the bandgap but changing the indirect semiconducting property on the other hand. Pt-C3N monolayer behaves more admirable performance upon NO2 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-C3N monolayer largely after adsorption of NO x gases. This is the basic sensing mechanism for Pt-C3N 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-C3N 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.