Synthesis of SnO2 nano-dodecahedrons with high-energy facets and their sensing properties to SO2 at low temperature

Dodecahedron-like SnO2 nanomaterial was synthesized via a solvothermal method under mild reaction condition. The morphological and structural characterization results indicated that the as-prepare dodecahedral SnO2 nanocrystallines with the average length of 130 nm and width of 45 nm were partially surrounded by high surface-energy {221} facets. The gas-sensing performance of the sample was investigated and the experiment results showed that the sensor had a good sensitivity to sulfur dioxide (SO2) at 183 °C. To 800 ppb SO2, the response could reach 1.32 and the response time was about 10 s. The good SO2-sensing performance of SnO2 nanocrystallines was closely related to the high surface-energy {221} facets whose surface possessed more dangling bonds and the corresponding SO2-sensing mechanism was discussed.