Synthesis of novel hollow ZnSnO3 cubic nanocages and their HCHO sensing properties.

Designed assembly of hollow nanostructures with well-defined non-spherical shapes is of great scientific and practical value and remains a great challenge. This paper presents a facile and one-pot hydrothermal synthesis of ZnSnO3 nanocages with geometrical cube-shape. The time-dependent hollowing evolution of the ZnSnO3 samples reveals a self-templating organization process, in which solid nanocubes of ZnSnO3 are formed firstly. Then due to the rapid coprecipitation process, the metastable inner part of the solid cubes dissolves and redeposits to the outer surface via Ostwald ripening, and finally the resultant hollowing process is achieved and ZnSnO3 crystallites reorganize into hollow archetectures. Moreover, the gas-sensing performance of these ZnSnO3 nanocages to formaldehyde (HCHO) is investigated. Due to the hollow interiors and good-permeation surfaces, these ZnSnO3 nanocages exhibit higher response, faster response-recovery, and other better sensing characteristics to HCHO compared with the solid ZnSnO3 nanocubes.