Low temperature hydrogen sensing using reduced graphene oxide and tin oxide nanoflowers based hybrid structure

In this paper, we have demonstrated a low temperature hydrogen (H2) sensor based on reduced graphene oxide (rGO) and tin oxide nanoflowers (SnO2 NFs) hybrid composite film. The addition of SnO2 NFs into rGO solution inhibits irreversible restacking and agglomeration of rGO and increases the active surface area for interaction with H2. This rGO-SnO2 NFs hybrid film sensor showed an excellent response to H2 at 60 °C at 200 ppm with an improvement of 126% compared to pure rGO which was used as a control sample. The sensor also showed good response and recovery time in comparison to pure rGO film. The highly improved H2 sensing characteristics of rGO-SnO2 NFs hybrid are due to its (a) unique structural geometry that increased the surface area for H2 adsorption, and (b) change in the width of depletion layer at the interface due to H2 interaction.