Room temperature DMMP gas sensing based on cobalt phthalocyanine derivative/graphene quantum dot hybrid materials

Abstract

In this study, two kinds of cobalt phthalocyanine (CoPc) derivatives containing hexafluoroisopropanol (HFIP) and hexafluorbisphenol A (6FBPA) substituents have been obtained. Graphene quantum dots (GQDs) were anchored to CoPc derivatives by π–π bonding, forming hybrid materials. They were employed to detect dimethyl methylphosphonate (DMMP) gas, an ideal simulant gas for sarin nerve gas, and achieved good gas response performance at room temperature. There are strong hydrogen bonds between the two functional group molecules (HFIP and 6FBPA) and the DMMP molecule, leading to their excellent response performance to DMMP molecules. GQDs can effectively increase the electrical conductivity of hybrid materials by π–π bonding with CoPc derivatives. Therefore, the response speed of the hybrid materials to DMMP gas has been significantly improved, and the minimum detection limit is 500 ppb, while maintaining excellent repeatability, stability and selectivity. Laser-assisted irradiation was used to solve the problem of the slow recovery of CoPc derivatives. This result demonstrates that these CoPc derivative/GQD hybrid materials are expected to be the raw materials of the sarin gas sensor.