Synthesis of self-assembled 3D hollow microspheres of SnO2 with an enhanced gas sensing performance

In this paper, three-dimensional (3D) SnO2 hollow microspheres composed of numerous subunits of nanorods are prepared through a facile one-pot hydrothermal method. These SnO2 microspheres are structurally characterized by X-ray diffraction, field-emission scanning electron microscope, and high resolution transmission electron microscope, respectively. It is shown that the hierarchical SnO2 microspheres ranged from 600 to 900 nm in diameter are constructed from self-assembled one-dimensional tetragonal prism SnO2 nanorods. Most importantly, the gas sensor based on these hierarchical SnO2 microspheres exhibits excellent selectivity and fast response–recovery capability to ethanol. The response and recovery times are 2.6 s and 11 s, respectively, if the sensor is exposed to 50 ppm ethanol at the optimal operating temperature of 280 °C. The present study could offer potential applications in gas sensors.