Solvothermal fabrication of rubidium tungsten bronze for the absorption of near infrared light

For fabricating the crystal of Rb_xWO₃, the solvothermal process was performed using a mixed medium of water and ethanol as solvent. It has been found that the morphological evolutions of samples were greatly changed as disordered nanoparticles, bundle of nanorods and microfibers with increasing content of water in the starting solution. Among them, sample synthesized with assistance of 3 ml water consisted of the nanorods with a diameter in the range of 80-150 nm, showing suitable size and morphology as near-infrared shielding material. On the merits of this nanostructure, the thin film of the Rb_xWO₃ nanorods realized excellent shielding of near-infrared light, meanwhile, it selectively transmitted the major part of visible light.