Pt nanoparticles functionalized 3D SnO2 nanoflowers for gas sensor application

3D SnO2 nanoflowers (NFs) assembled by rod-like nanostructures were synthesized by a facile hydrothermal method only using simple and inexpensive SnCl4·5H2O and NaOH as the starting materials, without using any surfactants or templates. The as-synthesized 3D SnO2 NFs were further functionalized by Pt nanoparticles (NPs) by a simple ammonia precipitate method, and the derived Pt NP-functionalized 3D SnO2 NFs were further investigated for gas sensor application using ethanol as a probe gas. Obtained results showed that the Pt NP-functionalized 3D SnO2 NF sensor exhibited much higher response in comparison with pure SnO2 sensor, altogether with short response/recovery times and good reproducibility. The enhanced gas sensing performances could be attributed to spill-over effect of Pt NPs for promoting gas sensing reactions, the synergic electronic interaction between Pt NPs and SnO2 support, the high surface-to-volume ratio and good electron mobility of the 1D SnO2 nanorod units, and unique 3D hierarchical flower-like nanostructures. It is also expected that the as-prepared 3D SnO2 NFs and Pt NP-functionalized product can be used in other fields such as optoelectronic devices, Li-ion battery and dye sensitized solar cells.