Facile synthesis of hierarchical W18O49 microspheres by solvothermal method and their optical absorption properties

Abstract

In this study, a simple route for the synthesis of hierarchical W₁₈O₄₉ assembled by nanowires is reported. The morphologies and formation of W₁₈O₄₉ single-crystal could be controlled by changing the concentration of WCl₆-ethanol solution. This synthesis strategy has the advantages that the hierarchical W₁₈O₄₉ microspheres could be economic synthesized at 180 °C without adding additives. Furthermore, efficient optical absorption properties in ultraviolet, visible and near-infrared region were obtained for the hierarchical W₁₈O₄₉ microspheres comparing with nanowires. These results will further promote the research of tungsten-based oxide nanomaterials.

Graphical abstract

The hierarchical W₁₈O₄₉ microspheres assembled by nanowires were solvothermally synthesized at 180 ºC via using tungsten chloride and ethanol as reactants and without adding morphology control agent or using expensive alcohol, such as isopropanol or acetic acid.

The W₁₈O₄₉ nanowires tend to form hierarchical microspheres with the increase of WCl₆-ethanol solution concentration.

The absorbance (300–2400 nm) of hierarchical W₁₈O₄₉ microspheres synthesized at 180 ºC were stronger than W₁₈O₄₉ nanowires synthesized at 200 ºC.