A kind of monoclinic vanadium dioxide nanowire and its preparation method and application

Abstract

The invention discloses a method for preparing a monoclinic phase vanadium dioxide nanowire. The method comprises the following steps: mixing a vanadium source, stearic acid and water, carrying out a hydrothermal reaction on the obtained mixed solution, sequentially centrifuging, washing and drying the obtained product after the hydrothermal reaction is completed, thereby obtaining the monoclinic phase vanadium dioxide nanowire. By utilizing the dual effects of inducing anisotropic growth of crystals through a reducing agent and a surfactant in the stearic acid, the monoclinic phase vanadium dioxide nanowire with thermal induced phase transition property can be prepared in a one-step process, the preparation process is simple, complicated equipment is not needed, the production cost is low, the reaction conditions are easy to control, and large-scale industrial production is easily realized; and moreover, the monoclinic phase vanadium dioxide nanowire is uniform in distribution and high in crystallinity and can be applied to the fields of smart windows, photoelectric switches, camouflage and stealth, infrared detection devices and the like.

Description

technical field [0001] The invention belongs to the field of inorganic functional materials, and in particular relates to a vanadium dioxide nanowire and a preparation method and application thereof. Background technique [0002] Since the first discovery of vanadium dioxide (VO 2 ) has excellent metal-insulator phase transition properties, VO 2 The sudden changes in optical, electrical and magnetic properties before and after the phase transition have become a hot spot for researchers. The phase transition temperature of vanadium dioxide is around 68°C. When the temperature is lower than 68°C, VO 2 It is an M-phase monoclinic crystal structure, showing the characteristics of an insulator; when the temperature is higher than 68 ° C, VO 2 Transformed into R-phase rutile structure, exhibiting metallic properties. VO 2 The sudden change of resistivity before and after the phase change can reach 4 orders of magnitude, and the sudden change of emissivity in the infrared band...

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Problems solved by technology

Wu Xingcai et al. (see Wu X, Tao Y, Dong L, etal. Materials Research Bulletin, 2005, 40(2): 315-321) synthesized VO by two-step hydrothermal method 2 nanowires, first synthesized (NH 4 ) 0.5 V 2 o 5 nanowire precursors, then annealed at 570 °C in vacuum to obtain VO 2 Nanowires, the method needs two steps to realize, the method is complicated, and consumes a lot of energy; CN101830510B Chinese patent document discloses a preparation method and application of rutile phase vanadium dioxide nanowires, the method first prepares vanadium ion solution or suspension , synthesized by hydrothermal reaction, then take out the hydrothermal kettle and put it into a water bath for rapid cooling, and naturally cool to room temperature to obtain VO 2 Nanowires, although this method adopts a one-step hydrothermal method, but this method requires rapid cooling, the process is complicated, and the safety factor is low

CN104192904A Chinese patent document discloses a super-long vanadium dioxide nanowire film and its preparation method, using vanadium pentoxide as a vanadium source, mixing vanadium pentoxide with a certain amount of hydrogen peroxide and oxalic acid and then putting it into hydrothermal In the kettle, react at a temperature of 80-200°C for 6-96 hours to obtain a vanadium dioxide ultra-long nanowire film. The vanadium dioxide nanowires prepared by this method are evenly distributed, with high yield and controllable length. However, the obtained product is B Phase vanadium dioxide, not suitable for applications in photoelectric switches, laser protection, etc.

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