Perovskite-type ZnSn(OH)6 hollow cubes with controllable shells for enhanced formaldehyde sensing performance at low temperature

Abstract Perovskite-type ZnSn(OH) 6 has attracted a lot of attention due to its exceptive electronic structure. In this work, ZnSn(OH) 6 hollow cubes with different shell numbers have been synthesized by repeated co-precipitation and alkaline etching at room temperature without any additional templates. Gas sensing performance of ZnSn(OH) 6 cubes with different shell numbers is compared, interestingly, gas sensing properties increase with increasing the shell numbers. As is expected, the sensor based on multi-shelled ZnSn(OH) 6 nanocubes not only shows the high response of 56.6–100 ppm formaldehyde and excellent selectivity, but also exhibits rapid response time (1 s) and selective to formaldehyde at its low concentration (100 ppm) at a low operating temperature of 60 °C. These excellent properties are mainly due to multilevel and hollow structure, the cube/cube junction and oxygen vacancies on the surface, which make them a promising material for formaldehyde sensors.