Direct formation of single crystal VO2(R) nanorods by one-step hydrothermal treatment

Pure phase VO2(R) nanorods were directly synthesized via the reduction of V2O5 by oxalic acid during one-step hydrothermal treatment. The products were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, FT-IR and UV–vis spectroscopy. By adding a proper amount of H2SO4 as morphology control agent, monodispersed single crystal VO2(R) nanorods were obtained from the hydrothermal solution for the first time at relatively lower temperature (260 °C) and even shorter time (4 h). The prepared nanorods showed very excellent thermochromic property with narrower hysteresis and lower phase transformation temperature compared with bulk materials.