Leaf-like tungsten oxide nanoplatelets induced by laser ablation in liquid and subsequent aging

A facile and chemically clean method, pulsed laser ablation in liquid medium (LAL), was utilized to produce precursor solutions, and leaf-like tungsten oxide (WO ₃) nanoplatelets were synthesized after sequential aging treatment of precursors. In this work, the effects of aging temperature, aging time, and pH value of precursor solutions have been investigated. The well-defined leaf-like WO ₃ nanoplatelets can only be achieved by aging the pristine precursor solutions at room temperature (25 °C) for 48 h. In particular, when the pH value of precursor solutions was decreased lower than 1.0, the obtained products were hierarchical quasi-spheres composed of several nanoplates. The preparation method reported here shows a novel synthetic approach to control and adjust the morphology and crystallite size of the prepared WO ₃ nanomaterials, which has potential applications in gas sensing, electrochromic devices, and photocatalysis.