Synthesis of double-shelled SnO2 hollow cubes for superior isopropanol sensing performance

Multi-shelled hollow structures have attracted extensive attention due to their promising performance in many areas. To date, however, the synthesis of non-spherical hollow multilayer porous structures remains a huge challenge. In this work, we present a straightforward synthesis route for the preparation of double-shelled SnO2 cubes without any additional templates. The sensor based on as-obtained double-shelled SnO2 hollow cubes shows high sensitivity and a fast response time (1 s) to isopropanol at a low operating temperature of 180 °C. The excellent gas sensing performance of the sensor to isopropanol can be attributed to the particular construction with multilayer hollow and mesoporous shells. Significantly, the extraction strategy also provides a new way for preparing non-spherical SnO2 hollow multilayer porous structures.