Preparation of Flower-like SnO₂ Nanostructures and Their Applications in Gas-Sensing and Lithium Storage

Hierarchical flower-like SnO 2 nanospheres have been prepared by one step hydrothermal reaction with surfactant-free. A possible growth mechanism is proposed. The application of this nanostructure in gas sensor for detecting ethanol reveals that the as-prepared SnO 2 nanospheres exhibit a high sensitivity and short response/recovery time. The flower-like SnO 2 nanostructures were also used as anode materials for Li-ion battery, whose cyclic voltammetry, charge–discharge galvanstatic behavior and cycle performance were examined. For the sample with 6 h hydrothermal time, a highly stable capacity about 570 mA g –1 after 100 cycles is achieved. The gas sensing properties are mainly determined by the specific surface area, and the 3D nanostructured films composed of flower-like SnO 2 nanospheres are favorable for the diffusion of gas molecules. At the same time, the high specific surface area of the flower-like SnO 2 nanospheres can provide more electrochemical active sites for Li storage, and the 3D nanostructured films composed of this nanostructure facilitate the diffusion of electrolyte. Furthermore, the short rods on the nanospheres may provide a buffer to alleviate volume change during the alloying and dealloying reactions between Sn and Li. The superior properties achieved here suggest that the as-prepared hierarchical flower-like SnO 2 nanostructures have potential application in Li-ion battery and gas sensor.