Au Nanoparticle-Functionalized 3D SnO 2 Microstructures for High Performance Gas Sensor

Three-dimensional (3D) nanostructures of metal oxides have been widely used for gas sensor devices. In this work, 3D porous SnO2 microstructures constructed by two-dimensional (2D) nanosheets were prepared via a simple hydrothermal process combined with subsequent annealing. Gold (Au) nanoparticles were successfully immobilized onto the surface of SnO2 nanosheets to serve as a sensitizer by a facile solution reduction process. This novel 3D Au/SnO2 microstructure has been investigated for gas senor and exhibits remarkably enhanced sensing performances to ethanol, e.g. high response, fast recovery time and good stability. The possible sensing mechanism is also discussed in terms of the special effect of Au functionalization.