Reduced graphene oxide based hybrid functionalized films for hydrogen detection: Theoretical and experimental studies

Abstract

In this work, hydrogen sensing characteristics of reduced graphene oxide (rGO) based functional nanomaterials are investigated with first principle calculations and experimental analysis. rGO doped with zinc oxide nanomaterial (i.e. rGO-ZnO), rGO-ZnO with silver nanoparticles (rGO-ZnO-Ag), rGO-ZnO with zirconium oxide (rGO-ZnO-ZrO2), rGO-ZnO doped with silver and palladium (rGO-ZnO-Ag-Pd) are investigated for their sensing capabilities. The influence of gas adsorption on the electronic features of the functional nanostructures are analyzed using the first principles density functional theory. The results of the computation reveal a considerable improvement of graphene oxide sensitivity in the hydrogen gas molecules following hybridization by ZnO, ZnO–Ag, ZnO–Ag–Pd and ZrO2. Fabrication and characterization of aforementioned functional materials and their hydrogen sensing performances are performed and essential sensing characteristics viz., sensitivity, response time, recovery time, reproducibility are also investigated. Out of the fabricated films, rGO-ZnO-Ag-Pd film is found to have the highest sensitivity towards hydrogen. It showed the sensitivity of ∼60% and highest performance factor (evaluated as the ratio of sensitivity to cycle time) among all films, including response time as 10 s and recovery time as 14 s. While performing sensing investigation, the distinct p-type behavior was observed for all the fabricated film. Obtained outcomes relate the promising future of rGO doped ZnO–Ag, ZnO–Ag–Pd and ZrO2 hybrid nano sensor in the advancement of sensitive gas sensors.

Keywords

• Reduced graphene oxide
• ZnO
• Hydrogen sensing
• Hybrid sensing films
• Density functional theory