Investigation of gas-sensitive properties of N-confused porphyrin-like graphene composites: A viewpoint of first principle

Abstract

The adsorptions of H₂S and HF molecules on N-confused porphyrin-like graphene composites G-CoN_xC_4-x (x = 2, 3, and 4) are investigated by first-principles calculations. Herein, the effective physisorption between G-CoN_xC_4-x substrates and H₂S/HF toxic gases is revealed by no significant charge transfer and large adsorption spacing. Meanwhile, the exothermic adsorption effect and the thermodynamic stability of G-CoN_xC_4-x substrate are explained by the negative adsorption energies and ab initio molecular dynamics, respectively. Evidently, the G-CoN₄ shows a remarkable enhancement in the HF sensing performance while G-CoN₃C₁ and G-CoN₂C₂ systems act as sharp responsive adsorbing H₂S samples, which is confirmed by the demonstrable changes in electronic and magnetic properties, as well as reasonable short recovery time. Our comprehensive work suggests that fabricating N-confounding is an effective strategy for engineering porphyrin-like graphene-based gas sensitivity features and developing on-demand sensor.