Regular Article

Controlled reduction of graphene oxide via hydrogen plasma for tuning sensitivity and recovery time of rGo based oxygen gas sensor

College of Science, Wasit University, Al Kut, Wasit, Iraq

^* e-mail: alialzubeidy@uowasit.edu.iq

Received: 15 May 2021
Accepted: 9 July 2021
Published online: 23 August 2021

Abstract

Graphene with high electronic transport, large surface-to-volume ratio and nanometer thickness is excellent for gas sensing applications. However, its sensitivity and recovery face serious limitations in practical considerations. In this study, graphene oxide (Go) sheets were synthesized and exposed to hydrogen (H₂) plasma to reduced it into a reduced graphene oxide (rGo) in a controlled procedure. In this regard, Go sheets were irradiated with plasma at different times and their electrical properties were evaluated. The results showed that with increasing bombardment time from 2 to 8 min, the conductivity of the sheets increased but for a longer time no significant increase was observed compared to 8 min. Raman spectroscopy also showed that the increase in plasma radiation led to an increase in defects within the sheets. The appearance of defects in rGo improved its sensitivity to oxygen (O₂) gas, but nevertheless reduced its recovery time. Therefore, by introducing the plasma bombardment process in a completely controlled way, we showed that the sensitivity and recovery time of rGo can be effectively tuned.