A method for preparing VO2(m) nano powders and films by spray pyrolysis

Abstract

The invention relates to a preparation method of VO2(M) nano powder and film through spray pyrolysis. The preparation method comprises the following steps: adding ammonium meta-vanadate into a glycol solvent, heating and stirring to form a transparent and uniform precursor solution with a concentration of 0.02 to 1 mol / L finally, then atomizing the precursor into droplets by an atomizer, spraying the droplets to a heated substrate by carrier gas, decomposing precursors on the substrate, after the products deposit for a while, and collecting the products namely VO2(M) nano powder or film; wherein a doping agent is added during the preparation process of precursor so as to reduce the phase change temperature of vanadium dioxide to room temperature. The operation of the preparation method is simple, the cost is largely reduced, the synthesis period of vanadium dioxide (M) is effectively shortened, and the preparation method can be applied to large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of inorganic functional materials, in particular to a spray pyrolysis method for preparing VO 2 (M) The method of nanopowder and thin film. Background technique [0002] Vanadium dioxide is a functional material with a variety of crystal structures, and the M-phase structure of vanadium dioxide has been studied the most in recent years because it has completely reversible metal-insulator phase transition characteristics at 68 °C. At low temperature, the M phase has a monoclinic crystal structure with high transmittance to infrared light; however, at high temperature, it transforms into an R phase with a tetragonal crystal structure, which has a high reflection effect on infrared light. At the same time, the resistivity before and after the phase transition will also change by 4-5 orders of magnitude. [0003] Therefore, VO 2 The (M) phase has a good application prospect in energy-saving windows and electronic devic...

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Problems solved by technology

[0004] At present, pyrolysis method (Chinese patent CN 1321067C) prepares VO 2 (M) Nanopowder: After the precursor is pulverized, it needs to be pyrolyzed at 350-500°C under vacuum conditions, and finally the product vanadium dioxide is obtained; the spray pyrolysis method (US Patent US5427763) requires H 2 Only by restoring the atmosphere can we get VO 2 (M), the above method requires stricter experimental atmosphere; patent CN 101391814A which discloses one-step hydrothermal synthesis of vanadium dioxide M phase, but the synthesis cycle is longer; recently, Zou et al. (J.Mater.Chem.A, 20 13,1,4250) and patent CN 102795968A which disclose that the vanadyl glycol precursor is thermally decomposed in the air to prepare M-phase vanadium dioxide. Although no special atmosphere is required, an oil bath or other methods are still required for synthesis Vanadyl glycolate, then pyrolyzed to give the product VO 2 (M), greatly increasing production costs

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