Simultaneous Synthesis of WO_3-x Quantum Dots and Bundle-Like Nanowires Using a One-Pot Template-Free Solvothermal...

Tungsten oxide (WO_3-x ), a new alternative to conventional semiconductor material, has attracted numerous attentions owning to its widespread potential applications. Various methods have been reported for the synthesis of WO_3-x nanostructures such as nanowires or nanodots. However, templates or surfactants are often required for the synthesis, which significantly complicate the process and hinder the broad applications. Herein, one-pot template/surfactant-free solvothermal method is proposed to synthesize the WO_3-x nanostructures including fluorescent quantum dots (QDs) and bundle-like nanowires simultaneously. The as-prepared WO_3-x QDs can be well dispersed in aqueous medium, exhibit excellent photoluminescent properties, and show an average size of 3.25 ± 0.25 nm as evidenced by transmission electron microscopy. Meanwhile, the diameter of the WO_3-x nanowires is found to be about 27.5 nm as manifested by the scanning electron microscope images. The generation mechanism for these two WO_3-x nanostructures are systematically studied and proposed. The WO_3-x QDs have been successfully applied in efficient fluorescent staining and specific ferric ion detection. Moreover, the WO_3-x nanowires can be utilized as effective dielectric materials for electromagnetic wave absorption.