Phase-controlled synthesis and gas-sensing properties of zinc stannate (ZnSnO3 and Zn2SnO4) faceted solid and hollow microcrystals

Well-defined faceted zinc stannate, including cubic ZnSnO3 and octahedral Zn2SnO4, microcrystals were synthesized in a large scale by a one-step chemical solution route, in which the phase control was simply accomplished by only changing stannic precursors. These faceted cubic ZnSnO3 and octahedral Zn2SnO4 microcrystals are easily converted to faceted hollow structures with a shape preserved through an acid etching process. Possible growth and etching mechanisms of these faceted microcrystals have been proposed. The hollow structures of zinc stannate were exploited as gas sensors and exhibit improved sensing performances to a series of gases (especially with regard to H2S and C2H5OH); moreover, the sensitivity and recovery time of Zn2SnO4 hollow octahedral structures to H2S and C2H5OH are both higher than those of the cubic structures, which may find potential industrial applications in detecting gases.