Hydrothermally synthesized SnO2-graphene composites for H2 sensing at low operating temperature

The flower-like SnO2 and a series of SnO2-graphene (S-G) composites have been synthesized through a simple one-pot hydrothermal method. The as-prepared products were characterized by XRD, FESEM, TEM, BET, XPS, and Raman spectroscopy. The results clearly revealed that the three-dimensional flower-like SnO2 hierarchical structure was destroyed by graphene nanosheets. The possible growth models for flower-like SnO2 and S-G composites were proposed based on the microstructure characterizations. Furthermore, the H-2 sensing responses of all samples were investigated at low operating temperatures (OT) between 30 and 180 degrees C. The results indicate that the S-G-2-based sensor exhibits the excellent H2 sensing response of 87.2 at a relatively low OT of 150 degrees C, which is about 70 times higher than that of pure SnO2. Mechanism of H-2 sensing of S-G composite has been discussed in terms of resistance change, which is influenced by the Schottky barrier at the interface of S-G composites. (C) 2015 Elsevier B.V. All rights reserved.