Preparation and gas sensing properties of flower-like WO3 hierarchical architecture

•Hierarchical flower-like WO3 assembled with ultrathin nanosheets has been synthesized through simple method.•The thickness of the nanosheets is only about 8.7 nm.•The response and recovery times of the sample sensor to ethanol are only 5–7 s and 6–9 s.•A possible formation mechanism has been proposed.

Flower-like WO3 hierarchical architecture has been successfully synthesized through a facile hydrothermal method. The morphology and structure were investigated via X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. The results indicated that the flower-like WO3 were self-assembled by many ultrathin petal-like nanosheets with thickness of several nanometers. A possible formation mechanism of 3D hierarchical architecture was proposed on basis of time dependent experiments. In addition, the well-defined WO3 hierarchical architectures exhibited high response and good selectivity to ethanol at 300 °C with fast response (5–7 s) and recovery (6–9 s) properties, which might substantially benefit from their layer-by-layer ultrathin petal structure.