A kind of tungsten trioxide-titanium dioxide electrochromic film and preparation method thereof

Abstract

The invention discloses a WO 3 ‑TiO 2 The preparation method of electrochromic thin film, using conductive glass as substrate, prepares a layer of TiO by hydrothermal method 2 array thin films; then perform a secondary hydrothermal reaction on TiO 2 WO grown on an array 3 , to prepare the described WO 3 ‑TiO 2 Electrochromic film. The preparation method is simple, low in cost and low in energy consumption, and the prepared WO 3 ‑TiO 2 Electrochromic thin films with nanoscale TiO 2 Array structure, TiO 2 The gaps and surfaces of the array are covered with WO 3 Nanorods and nanocrystals increase the specific surface area of ​​the film and shorten the diffusion path of ions; in addition, WO 3 It is mainly a monoclinic intercalated water structure, which can significantly reduce the energy barrier of ion diffusion and increase ion flux; making the WO 3 ‑TiO 2 The electrochromic film has dual-frequency regulation in the visible-near-infrared band, fast response time, high coloring efficiency, and excellent electrochemical performance.

Description

technical field [0001] The invention relates to the field of electrochromic films, in particular to a tungsten trioxide-titanium dioxide electrochromic film and a preparation method thereof. Background technique [0002] Electrochromic technology refers to a stable and reversible change in the color or optical properties (reflectivity, transmittance, absorption, etc.) of a material under the action of an external voltage. Its essence is the double injection and double extraction of ions and electrons. electrochemical reaction. As the most important core functional part of electrochromic devices, electrochromic thin films have received a lot of attention and extensive research by scholars at home and abroad. [0003] Traditional electrochromic materials are mainly aimed at spectral modulation in the visible light region (0.38-0.78 μm), while the near-infrared light region (0.78-3.5 μm) accounts for about 55% of the total energy of solar radiation. While independently modula...

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Problems solved by technology

However, the preparation process of the above studies is complicated, and all of them only investigated the light modulation and electrochemical performance of the composite film in the visible light region, and did not involve the modulation of near-infrared light and the "dual-frequency" electrochromic effect.

[0009] There are also studies (Cai G F, Zhou D, Xiong Q Q, et al. Efficient electrochromic materials based on TiO 2 @WO 3 core / shell nanorod arrays[J].Solar Energy Materials & Solar Cells, 2013,117:231-238.) TiO was prepared by combining hydrothermal and electrodeposition methods 2 @WO 3 Core / shell nanorod array electrochromic material, the composite thin film with porous structure and pure WO 3 and TiO 2 Compared with the thin film, it has significantly enhanced electrochromic properties, with modulation amplitudes of 57.2%, 70.3% and 38.4% at 750nm, 1800nm ​​and 10μm, respectively, but the coloring efficiency of the thin film in this study is relatively low (only at 750nm 67.5cm 2 C -1 ) and failed to achieve selective regulation of visible light bands and near-infrared light bands

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