One-step hydrothermal synthesis of V1−xWxO2(M/R) nanorods with superior doping efficiency and thermochromic properties

Abstract

Pure phase V_1−xW_xO₂(M/R) nanorods with superb metal–insulator transition properties were obtained in tungsten (W)-doped level ranges from 0.5 to 2.0 at% using a one-step hydrothermal treatment without additional annealing steps. The assured level of W doping greatly promotes the grain growth of pure phase vanadium oxide (VO₂)(M/R) and simultaneously the phase transition temperature (T_c) is depressed as much as 103 °C per at% W for the V_1−xW_xO₂ nanorods when x = 1.0–2.0 at%. After mixing the pure phase VO₂(M) (W-doped 0.5 at%, phase transition at 47 °C) nanorods with acrylic resin, the integrated visible transmission of the VO₂ composite coating on glass is up to 60.6% and the integrated solar modulation efficiency is up to 10.3%. These results mean that the superior thermochromic property will greatly favor the practical application of VO₂-based smart windows.