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 (WO3) 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 WO3 nanoplatelets can only be achieved by aging the pristine precursor solutions at room temperature (25 degrees 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 WO3 nanomaterials, which has potential applications in gas sensing, electrochromic devices, and photocatalysis.