Improving the sensitivity of graphyne nanosensor by transition metal doping

The concern with air quality and safety urges for design and development of new gas sensors. Graphyne presents comparable electronic mobility and mechanical properties to graphene, with the advantage of naturally allowing single-atom dispersion into acetylenic pores. Therefore, we investigate the detection ability of transition metal (TM: Fe and Ni) doped graphyne (Gy) toward CO, NO, NO2, and CO2 gas molecules. Our aim is to engineer the electronic characteristics and further improve the sensing properties. We model the sensing device using TM-doped Gy nanoribbons (TM-GyNR) using density functional theory combined with non-equilibrium Green's functions. Most of the gases presented chemical adsorption on the TM-GyNR, with slightly weaker interaction for gas/NiGyNR systems than gas/FeGyNR. These differences produced recovery times compatible with room temperature detectors for CO and NO (NiGyNR) and CO2 (FeGyNR) gases. We obtain gas sensitivity as high as 117% for CO/FeGyNR and 300% for NO2/NiGyNR. Due to mutual differences in binding energies and sensitivity among the gases, NiGyNR and FeGyNR also present high selectivity to distinguish the target molecules. Finally, our findings suggest that TM functionalization of graphynes is a promising strategy for engineering the sensitivity of gas nanosensors.

Automated summary

The concern for air quality and safety has led to the need for new gas sensors. Graphyne, which has similar electronic and mechanical properties as graphene, allows for single-atom dispersion into acetylenic pores. This study investigates the detection ability of transition metal-doped graphyne towards different gas molecules and suggests that TM functionalization of graphynes is a promising strategy for engineering the sensitivity and selectivity of gas nanosensors.