Flower-like In2O3 hierarchical nanostructures: synthesis, characterization, and gas sensing properties

Abstract

Hierarchical In₂O₃ nanostructures with flower-like morphology were synthesized by annealing In(OH)₃ precursors prepared via a one-step hydrothermal method using the mixed solution of N,N-dimethylformamide (DMF) and deionized water as solvent. The crystal structure and morphology of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ adsorption–desorption analyses. The results revealed that the synthesized flower-like In₂O₃ hierarchical nanostructures were constructed from In₂O₃ nanoplates which connected with each other to form flower-like architecture. On the basis of experimental results, a possible mechanism for the formation of flower-like In₂O₃ hierarchical nanostructures was considered. Moreover, gas sensing investigation showed that the sensor based on flower-like In₂O₃ hierarchical nanostructures exhibited a superior response, good selectivity and stability to ethanol gas. The enhancement in gas sensing properties was attributed to their unique structure, large surface areas, and more surface active sites.