Effects of different petal thickness on gas sensing properties of flower-like WO<inf>3</inf>·H<inf>2</inf>O hierarchical architectures

Abstract Hierarchical architectures consisting of two-dimensional (2D) nanostructures are of great interest for potential use in recent year. Here, we report the successful synthesis of four hierarchical tungsten oxide flower-like architectures via a simple yet facile hydrothermal method. The as-prepared WO<inf>3</inf>·H<inf>2</inf>O hierarchical architectures are in fact assembled with numerous nanosheets or nanoplates. Through a comprehensive characterization of microstructures and morphologies of the as-prepared products, we find that petal thickness is a key factor for affecting gas-sensing performances. We further propose a possible growth mechanism for the four flower-like architectures. Moreover, gas-sensing measurements showed that the well-defined sheet-flower WO<inf>3</inf>·H<inf>2</inf>O hierarchical architectures exhibited the excellent gas-sensing properties to ethanol owing to their largest amount of thin petal structures and pores.