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 <tex-math notation="LaTeX">BC-C </tex-math> 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 <tex-math notation="LaTeX">Ead </tex-math> of −2.25 and −1.99 eV, and <tex-math notation="LaTeX">QT </tex-math> 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.