Investigation of fiber laser-induced porous graphene electrodes in controlled atmospheres for ZnO nanorod-based NO2 gas sensors

This study aims to develop fiber laser-induced graphene (LIG) on polyimide films fabricated under a chamber with air, vacuum, or nitrogen atmospheres. Moreover, ZnO nanorods with a large specific surface area were synthesized by a facile and low-cost hydrothermal method. The ZnO nanorod sensing solution was drop-cast on the LIG surface with porous structures as a sensing layer for the NO2 gas sensor. The characteristics of the LIGs and ZnO nanorods including the surface morphology, elemental content, crystal structure, elemental composi-tion, and chemical bond were investigated. The ZnO gas sensor with LIG electrodes fabricated in air has outstanding sensing performance in a high response (251.71 %), fast response and recovery times (9.5 s and 8.3 s, respectively), and response stability at a NO2 concentration of 1000 ppb. In addition, the ZnO gas sensor with LIG electrodes fabricated in vacuum has an excellent sensitivity. Based on the ZnO nanorod/LIG-based NO2 gas sensor with a high response and sensitivity, the proposed gas sensors can be combined with the Internet of Things and widely used in real-time detecting harmful gases.

Automated summary

This study focuses on developing fiber laser-induced graphene (LIG) on polyimide films under different atmospheres. ZnO nanorods with a large specific surface area were synthesized via a cost-effective hydrothermal method. LIG surface with porous structures was used as a sensing layer for NO2 gas sensor by drop-casting ZnO nanorod sensing solution. The gas sensor fabricated in air showed outstanding sensing performance with high response (251.71%), fast response and recovery times (9.5 s and 8.3 s, respectively), and response stability at 1000 ppb NO2 concentration. The vacuum-fabricated ZnO gas sensor exhibited excellent sensitivity. These ZnO nanorod/LIG-based gas sensors can be combined with the Internet of Things for real-time detection of harmful gases.