Holey reduced graphene oxide nanosheets for high performance room temperature gas sensing

Abstract

Holey reduced graphene oxide (RGO) sheets were formed by one-pot hydrothermal treatment of graphene oxide (GO) at a dilute concentration (0.25 mg ml⁻¹). The holes were generated through a carbon gasification reaction with the steam created in the hydrothermal system. The perforated structure provides not only sufficient active sites for molecule adsorption, but also provides channels for gas diffusion. Thus, the sensor based on the networks, which were constructed from the perforated RGO nanosheets, exhibited an enhanced sensitivity to toxic NO₂ gas at ppb level, surpassing the performance of the annealed RGO. Interestingly, the polarity of the holey RGO transformed from p-mode to n-mode after exposure to NH₃ and a repeatable sensing to NH₃ within-mode nanoporous RGO was observed. The results demonstrate that structure modification of RGO through perforation is a promising approach for improving the sensing performance. Furthermore, the perforated RGO obtained through a one-pot hydrothermal process can be used for high performance gas sensing at room temperature, demonstrating its practical application in flexible and wearable gas sensors based on the good mechanical flexibility of RGO.