Hydrothermal Fabrication of WO₃ Hierarchical Architectures: Structure, Growth and Response

Recently hierarchical architectures, consisting of two-dimensional (2D) nanostructures, are of great interest for potential applications in energy and environmental. Here, novel rose-like WO₃ hierarchical architectures were successfully synthesized via a facile hydrothermal method. The as-prepared WO₃ hierarchical architectures were in fact assembled by numerous nanosheets with an average thickness of ~30 nm. We found that the oxalic acid played a significant role in governing morphologies of WO₃ during hydrothermal process. Based on comparative studies, a possible formation mechanism was also proposed in detail. Furthermore, gas-sensing measurement showed that the well-defined 3D WO₃ hierarchical architectures exhibited the excellent gas sensing properties towards CO.