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. (paper)