Fabrication and characterization of WO3 flocky microspheres induced by ethanol

The novel tungsten trioxide flocky microspheres induced by ethanol were successfully obtained via a simple and convenient hydrothermal route. The as-prepared products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, BET surface area measurement and UV–Vis diffuse reflectance spectroscopy. WO3 powder prepared with volume ratio (vethanol/vwater) of 40% revealed a complete flocky microsphere structure with particle size of 3.0–4.0 μm and exhibited good photochromic property. The possible formation mechanism of the flocky microspheres was proposed and the improved photochromic properties were also investigated.

Graphical AbstractWO3 flocky microspheres with diameter of 3.0–4.0 μm induced by ethanol were obtained via a hydrothermal route. With the addition of ethanol, the state of the particles agglomeration decreased remarkably; the particle sizes and the aspect ratio of needles on the surface of particles increased. The volume ratio (vethanol/vwater) of 40% was the optimization. The enhanced photochromic properties are mainly due to the increased specific surface area.Figure optionsDownload as PowerPoint slideHighlights
► The microspherical WO3 induced by ethanol was successfully obtained.
► The formation process of WO3 microsphere was proposed.
► The enhanced photochromic property of WO3 was investigated.