Facile synthesis and enhanced gas sensing properties of In2O3 nanoparticle-decorated ZnO hierarchical architectures

In2O3 nanoparticle-decorated flowerlike ZnO hierarchical architectures are fabricated by a simple and facile two-step approach, including the room temperature synthesis of flowerlike ZnO and the subsequent decoration with In2O3 nanoparticles, and developed for HCHO gas detection. The SEM, TEM and HRTEM images indicate that the In2O3 nanoparticles have successfully grown and are closely attached to the surface of the ZnO. The special 3D hierarchical architectures, the appropriate decoration amount of In2O3 nanoparticles and the incorporation of interfaces between ZnO nanosheets and the In2O3 nanoparticles endow In2O3-decorated ZnO nanostructured sensors with enhanced HCHO gas sensing performances. A multistage reaction formation mechanism of flowerlike hierarchical nanostructures and a morphology-dependent sensing mechanism are proposed.