Method for reducing phase transition temperature of vanadium dioxide through W<6+> doping

Abstract

The invention discloses a method for reducing a phase transition temperature of vanadium dioxide through W<6+> doping. The method is characterized by comprising the steps: weighing 0.3 g of V2O5 and 0.4 g of oxalic acid according to a molar ratio of about 1:2, adding a certain amount of tungstic acid, then adding 40 ml of distilled water, stirring at the room temperature to completely dissolve, and then transferring to a vessel with a polytetrafluoroethylene liner, and sealing with a stainless steel shell; keeping a hydrothermal treatment temperature of 240 DEG C for 3 days; after hydrothermal treatment, naturally cooling to the room temperature; filtering the obtained experimental precipitate, and then respectively washing with distilled water and alcohol for a plurality of times; followed by keeping the sample at the temperature of 80 DEG C for 10 h in a baking oven; and then annealing the obtained sample in a nitrogen atmosphere to obtain the product. The method has the advantages that: through the hydrothermal method, a certain amount of tungstic acid is added, and a doped VO2 powder is prepared at the relatively low temperature of 240 DEG C; and the method has simple process, good reproducibility and high degree of controllability, and enables the phase transition temperature of the VO2 (M / R) nanopowder to be decreased from 67 DEG C to 42 DEG C through W<6+> doping.

Description

technical field [0001] The present invention relates to a kind of through W 6+ The invention discloses a method for lowering the phase transition temperature of vanadium dioxide by doping, which belongs to the field of nanometer material and nanotechnology. Background technique [0002] In traditional thermochromic materials VO 2 Has excellent performance. Vanadium dioxide exists in various forms of stable and metastable polymorphs, which in this system include orthodox rutile VO 2 (R) phase and monoclinic structure of VO 2 VO of the (M) phase and at least three metastable phases 2 (B), VO 2 (A) including the recently discovered VO 2 (C). VO 2 (M) The phase transition temperature is about 68 °C, most notably accompanied by a phase transition from a semiconductor to a metallic state, with a sudden change in electrical resistance and a change in optical properties. However, this temperature is a bit high compared with the ambient temperature, and some industries requi...

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Problems solved by technology

But the preparation of VO 2 There are few reports on doped powder materials

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