Synthesis of hierarchical SnO2 nanoflowers and their high gas-sensing properties

• We used glycol and de-ionized water jointly as solvent, not only de-ionized water.
• Our sample has highly selectivity and sensitivity to 200 ppm acetone at 260 °C.
• The gas sensor with rapidly response time (12 s) and recovery time (10 s).

The hierarchical SnO2 flower-like nanostructure was successfully synthesized by a low-cost and simple hydrothermal method at 160 °C for 22 h. These uniform SnO2 nanoflowers were composed of nanosheets. The polyvinyl pyrrolidone (PVP), sodium citrate (Na3C6H5O7·2H2O) and ammonia (NH3·H2O) played a pivotal role in the growth of nanoflowers, and the possible formation mechanism was also proposed according to the results. Moreover, the gas sensor based on this structure showed a response about 160 and a response time around 12 s to 200 ppm acetone at the optimum operating temperature of 260 °C. It indicated that our sample has high response, fast response time and good selectivity to acetone. Thus, the peculiar structure of our sample endowed acetone detection with widely application prospects.