Morphology and phase controlled synthesis of Cs_xWO₃ powders by solvothermal method and their optical properties

In this work, the effects of processing parameters such as reaction solvent, autoclave rotating and Cs source on the morphology and microstructure of Cs_xWO₃ products were investigated. The as-synthesized Cs_xWO₃ samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and spectrophotometer. The results indicate that using ethanol as solvent is favorable for obtaining pure hexagonal Cs_0.20WO₃ or Cs_0.30WO₃ crystals. With the increase of water content in the reaction solution, some impurities such as WO₃ and WO₃(H₂O)_0.333 easily form due to the decrease of reducing atmosphere. The autoclave rotating during the reaction is very helpful for decreasing the particle size, but is not very favorable for forming rod-like hexagonal Cs_xWO₃ to some extent. In addition, the reaction solvent, autoclave rotating and Cs source have great effects on the optical absorption of Cs_xWO₃ products.