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 degrees 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.