▎ 摘　　要

SnO2@ reduced graphene oxide (SnO2@ rGO) nanocomposites are prepared using a freeze-drying method followed by heat treatment. The structure and morphology of the nanocomposites are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy. A large number of small uniform SnO2 nanorods are successfully anchored on the surface of the rGO nanosheet, and a p-n junction is formed at their interface. In addition, the gas-sensing properties of SnO2@ rGO are tested using different concentrations of H-2 at a low operating temperature of 80 degrees C. The SnO2@ rGO sensor exhibits outstanding gas-sensing properties towards H-2, such as fast response and recovery, high sensitivity, selectivity, and stability. The sensor response to 1% H-2 at 80 degrees C was approximately 1.58, and the response and recover times were 15 s and 61 s, respectively. The satisfactory gas-sensing performance can be attributed to the large specific surface area, high electrical conductivity and width of the electron depletion layer. A possible gas-sensing mechanism is also proposed.