The synthesis and fast ethanol sensing properties of core–shell SnO2@ZnO composite nanospheres using carbon spheres as templates

Abstract

Core–shell SnO₂@ZnO composite nanospheres were successfully prepared by using carbon spheres as sacrificial templates via a facile three-step procedure including a hydrothermal method. In contrast, pristine SnO₂ nanospheres and ZnO nanoparticles were obtained through a similar method with different steps, respectively. The composition and structures of the as-synthesized samples were confirmed by a series of characterization procedures. The obtained composite materials exhibited the special core-in-hollow-shell structure at the nanometer level. And as potential sensing materials, the obtained core–shell SnO₂@ZnO composite nanomaterials demonstrated better gas sensing properties to ethanol including higher response, better selectivity, faster response and favorable repeatability, which may be related to the special core-in-hollow-shell structure with a porous surface and the hetero-contact between two different metal oxide semiconductors.