A novel reduction–hydrolysis method of preparing VO2 nanopowders

A novel and convenient reduction–hydrolysis method was developed to make high-purity VO2 nanopowders. The products have been studied with XRD, IR, XPS, and DTA. The nanopowders exhibited a strong crystallographic transition to the rutile-type structure around 68–72 °C. The XRD patterns and TEM images of products showed that the average size of samples was in the range of 30–40 nm. The XPS results demonstrated that the vanadium exists as V4+ ions in the products. We also found that the phase transition temperature of products decreased by tungsten doping.