阅读说明：本技术 一种三氧化钨-二氧化钛电致变色薄膜及其制备方法 (Tungsten trioxide-titanium dioxide electrochromic film and preparation method thereof ) 是由 王立坤 刘涌 莫建良 韩高荣 于 2021-09-14 设计创作，主要内容包括：本发明公开了一种WO-(3)-TiO-(2)电致变色薄膜的制备方法,以导电玻璃为基板,采用水热法制备一层TiO-(2)阵列薄膜；再进行二次水热反应在TiO-(2)阵列上生长WO-(3),制备得到所述的WO-(3)-TiO-(2)电致变色薄膜。该制备方法简单、成本低廉、能耗低,制得的WO-(3)-TiO-(2)电致变色薄膜具有纳米级的TiO-(2)阵列结构,TiO-(2)阵列的间隙和表面覆盖有WO-(3)纳米棒和纳米晶,增大了薄膜的比表面积,缩短了离子的扩散路径；此外,WO-(3)主要为单斜相插层水结构,可以显著降低中离子扩散的能垒,增加离子通量；使得该WO-(3)-TiO-(2)电致变色薄膜具有可见-近红外波段双频调控功能,响应时间快、着色效率高、电化学性能优异。(The invention discloses a WO 3 ‑TiO 2 The preparation method of the electrochromic film comprises the steps of preparing a layer of TiO by using a hydrothermal method by using conductive glass as a substrate 2 An array film; then carrying out a secondary hydrothermal reaction on the TiO 2 Growth of WO on arrays 3 Preparation of the WO 3 ‑TiO 2 An electrochromic film. The preparation method is simple, low in cost and low in energy consumption, and the prepared WO 3 ‑TiO 2 Electrochromic film with nano-grade TiO 2 Array structure, TiO 2 The array is covered with WO on the gaps and surfaces 3 The nano-rods and the nano-crystals increase the specific surface area of the film and shorten the diffusion path of ions; furthermore, WO 3 The material is mainly of a monoclinic phase intercalation water structure, so that the energy barrier of ion diffusion in the process can be remarkably reduced, and the ion flux is increased; so that the WO 3 ‑TiO 2 The electrochromic film has visible-near infraredThe wave band dual-frequency regulation function, the response time is fast, the coloring efficiency is high, and the electrochemical performance is excellent.)

1. WO (WO)₃-TiO₂The preparation method of the electrochromic film is characterized by comprising the following steps of:

(1) TiO is prepared by taking concentrated hydrochloric acid, deionized water and butyl titanate as raw materials₂Precursor solution, putting conductive glass into TiO₂In the precursor solution, the precursor solution is subjected to hydrothermal reaction to prepare the precursor solution with TiO₂Conductive glass of the array;

(2) mixing a sodium tungstate dihydrate solution with a hydrochloric acid solution to obtain a precipitate, removing supernatant, washing the precipitate with deionized water until the pH value of a washing solution is 2.0-3.0, and adding H₂O₂The solution is used to dissolve the precipitate completely to obtain WO₃A precursor solution;

(3) will carry TiO₂Conductive glass of the array is put into WO₃Adding urea into the precursor solution to perform a secondary hydrothermal reaction to obtain the WO₃-TiO₂An electrochromic film.

2. WO according to claim 1₃-TiO₂The preparation method of the electrochromic film is characterized in that in the step (1), the volume ratio of concentrated hydrochloric acid to deionized water to butyl titanate is 1: 1: 0.03 to 0.10.

3. WO according to claim 1₃-TiO₂The preparation method of the electrochromic film is characterized in that the conductive glass is ITO conductive glass or FTO conductive glass.

4. WO according to claim 1₃-TiO₂The preparation method of the electrochromic film is characterized in that in the step (1), the hydrothermal reaction condition is 120-150 ℃ and 1.5-3 h.

5. WO according to claim 1₃-TiO₂The preparation method of the electrochromic film is characterized in that in the step (2), the molar ratio of sodium tungstate dihydrate to hydrochloric acid is 1: 2-3.

6. WO according to claim 1₃-TiO₂The preparation method of the electrochromic film is characterized in that in the step (3), the WO is₃The ratio of the precursor solution to the urea is 20 mL: 0.008-0.014 g.

7. WO according to claim 1₃-TiO₂Electrochromic filmThe preparation method of the membrane is characterized in that in the step (3), the secondary hydrothermal reaction conditions are as follows: 140-180 ℃ for 2-4 h.

8. WO according to any of claims 1 to 7₃-TiO₂WO prepared by preparation method of electrochromic film₃-TiO₂An electrochromic film.

9. WO according to claim 8₃-TiO₂Electrochromic film, characterized in that said WO₃-TiO₂In electrochromic films, TiO₂The thickness of the array is 50-300 nm.

10. WO according to claim 8₃-TiO₂Electrochromic film, characterized in that said WO₃-TiO₂In electrochromic films, WO₃-TiO₂The thickness of the layer is 300 to 600 nm.

Technical Field

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

The electrochromic technology is characterized in that under the action of an external voltage, the color or optical properties (reflectivity, transmittance, absorptivity and the like) of a material are stably and reversibly changed, and the essence of the electrochromic technology is an electrochemical reaction of double injection and double extraction of ions and electrons. The electrochromic film is used as the most important core functional part in the electrochromic device, and obtains a great deal of attention and extensive research of scholars at home and abroad.

The traditional electrochromic material mainly aims at the spectrum modulation of a visible light region (0.38-0.78 mu m), and in the total energy of solar radiation, a near infrared region (0.78-3.5 mu m) accounts for about 55%. The realization of the double-frequency electrochromic effect by independently modulating visible light and near infrared light is a research hotspot and difficulty of electrochromic materials in recent years.

WO₃As a preferred material of the cathode electrochromic layer with excellent performance, the modulation can be realized in a visible light region and a near infrared light region due to polaron absorption and plasma resonance effects. However, at present, WO with near infrared modulation capability₃Much of the research in (1) has focused on monoclinic non-stoichiometric tungsten oxide (WO)_3-x) Chemically unstable and slowly oxidized even when exposed to air at room temperature, directly prepared stoichiometric WO₃The research on the 'double-frequency' regulation effect of the film is not reported.

TiO₂The material has the characteristics of good electrochemical stability, light modulation property, reversibility and expandability, low-cost preparation and the like, and is one of important candidate materials for the application of the electrochromic intelligent window. However, TiO₂The film has the defects of low color development efficiency, high color development voltage requirement, slow switching dynamics and the like in an electrochromic device, and the performance requirement of an electrochromic material can not be met.

To increase WO₃And TiO₂The electrochromic effect of (A), known from the literature (T. Dhangayuthapani, R. Sivakumar, D. Zheng, et al. WO₃/TiO₂ hierarchical nanostructures for electrochromic applications[J]Mat.Sci.Semicon.Proc.2020,123: 105515)Combines chemical bath deposition and spray deposition technology, adopts two-step process to prepare WO at low temperature₃/TiO₂Composite films that can accommodate more charge due to interconnected bundles of nanoplates, facilitating faster charge transport, in particular, WO₃-TiO₂The complementarity between the layers results in more efficient electrochromic properties.

There is also literature (K.R.Reyes-Gil, Z.D.Stephens, V.Stavila, et al.composite WO₃/TiO₂nanostructures for high electrochromic activity.[J]Acs appl. Mater. Interf.2013,7(4):2202.) A titanium foil anodizing method was used to prepare TiO₂Nanotube array (TiO)₂NT), adding TiO₂The NT is peeled off from the titanium substrate, attached to FTO glass, and then electrodeposited with a layer of WO₃Construction of WO₃/TiO₂A composite membrane.

With pure WO₃And TiO₂Material comparison, composite WO₃/TiO₂The nanostructures have higher ion storage capacity, better stability, enhanced color change contrast and longer memory time. However, the research and preparation processes are complex, and only the light modulation effect and the electrochemical performance of the composite film in a visible light region are examined, and the modulation of near infrared light and the double-frequency electrochromic effect are not involved.

There is also a study (Cai G F, Zhou D, Xiong Q, et al. effective electrochemical materials based on TiO₂@WO₃ core/shell nanorod arrays[J].Solar Energy Materials&Solar Cells,2013,117:231-238.) preparation of TiO by a method combining hydrothermal and electrodeposition₂@WO₃Core/shell nanorod array electrochromic material, composite film with porous structure and pure WO₃And TiO₂The films had significantly enhanced electrochromic properties compared to the films, with modulation amplitudes of 57.2%, 70.3% and 38.4% at 750nm, 1800nm and 10 μm, respectively, but the film coloration efficiency in this study was relatively low (only 67.5cm at 750 nm)² C^-1) And selective regulation of visible light wave band and near infrared light wave band can not be realized.

Chinese patent publication No. CN102168247ATherein discloses a TiO₂/WO₃The preparation method of the composite film comprises the following steps: sputtering of TiO on a substrate by magnetron sputtering₂Film, re-sputtering WO₃Film, finally annealing to obtain TiO₂/WO₃Compounding a film; chinese patent publication No. CN109468674B discloses a TiO compound₂/WO₃The preparation method of the nano composite film comprises the following steps: TiO prepared on titanium foil surface by anode oxidation method₂Based on the nanotube array film, adopting the electrodeposition technology on TiO₂WO with electronic storage function coated on surface of nanowire₃Nano particles to obtain energy-storage TiO₂/WO₃A nanocomposite film.

Disclosure of Invention

The invention provides a WO₃-TiO₂The preparation method of the electrochromic film is simple to operate and strong in controllability, and the prepared WO is₃-TiO₂The electrochromic film can realize selective modulation of near-infrared light wave bands and visible light wave bands, and has the advantages of fast response time, high coloring efficiency and excellent electrochemical performance.

The technical scheme is as follows:

WO (WO)₃-TiO₂The preparation method of the electrochromic film comprises the following steps:

(1) TiO is prepared by taking concentrated hydrochloric acid, deionized water and butyl titanate as raw materials₂Precursor solution, putting conductive glass into TiO₂In the precursor solution, the precursor solution is subjected to hydrothermal reaction to prepare the precursor solution with TiO₂Conductive glass of the array;

(2) mixing a sodium tungstate dihydrate solution with a hydrochloric acid solution to obtain a precipitate, removing supernatant, washing the precipitate with deionized water until the pH value of a washing solution is 2.0-3.0, and adding H₂O₂The solution is used to dissolve the precipitate completely to obtain WO₃A precursor solution;

(3) will carry TiO₂Conductive glass of the array is put into WO₃Adding urea into the precursor solution to perform a secondary hydrothermal reaction to obtain the WO₃-TiO₂An electrochromic film.

Hair brushThe two-step hydrothermal method is adopted, and rutile-structured TiO is deposited on a conductive glass substrate in sequence₂WO of mixed array and monoclinic system of hexagonal system and intercalated water structure₃Obtaining WO with visible-near infrared band double-frequency regulation function₃-TiO₂An electrochromic film.

Preferably, in the step (1), the volume ratio of concentrated hydrochloric acid, deionized water and butyl titanate is 1: 1: 0.03 to 0.10.

Preferably, the conductive glass is ITO conductive glass or FTO conductive glass.

Preferably, in the step (1), the conductive glass is ultrasonically cleaned by deionized water and alcohol and then put into TiO₂Hydrothermal reaction occurs in the precursor solution.

The better TiO with the proper thickness on the surface of the conductive glass can be prepared by adopting the hydrothermal reaction₂The array structure can increase the specific surface area of the film, shorten the diffusion path of ions and is beneficial to improving the response time and the coloring efficiency of electrochromism.

Preferably, in the step (1), the hydrothermal reaction condition is 120-150 ℃ and 1.5-3 h.

Preferably, in the step (2), the molar ratio of the sodium tungstate dihydrate to the hydrochloric acid is 1: 2-3.

Preferably, in step (3), said WO₃The ratio of the precursor solution to the urea is 20 mL: 0.008-0.014 g.

Preferably, in the step (3), the secondary hydrothermal reaction conditions are as follows: 140-180 ℃ for 2-4 h. Under corresponding reaction conditions, the method is favorable for generating the WO with moderate thickness, good crystallization quality and mixed hexagonal crystal system and intercalated water structure monoclinic crystal system₃The structure ensures that the obtained electrochromic film has proper initial transmittance and good electrochromic performance.

The invention also provides said WO₃-TiO₂WO prepared by preparation method of electrochromic film₃-TiO₂An electrochromic film.

Preferably, said WO₃-TiO₂Electrochromic displayIn the film, TiO₂The thickness of the array is 50-300 nm.

Preferably, said WO₃-TiO₂In electrochromic films, WO₃-TiO₂The thickness of the layer is 300 to 600 nm.

Said WO₃-TiO₂The electrochromic film grows nano-grade TiO on the surface of the conductive glass₂Array film, TiO₂The gaps and surfaces of the array film are covered with WO₃Nanorods and nanocrystals to form WO₃-TiO₂A layer; the TiO being₂TiO with rutile structure in array film₂，WO₃WO with nanorod and nanocrystal intercalated water structure mainly in monoclinic phase₃The state exists and also contains a small amount of hexagonal phase WO₃。

Said WO₃-TiO₂In electrochromic films, TiO₂And WO₃The nano structure increases the specific surface area of the film, shortens the diffusion path of ions and is beneficial to the rapid embedding and releasing of the ions in the film; the monoclinic phase intercalation water structure can obviously reduce WO₃The energy barrier of medium ion diffusion increases the ion flux, and improves the WO₃-TiO₂Electrochemical properties of the electrochromic film.

Compared with the prior art, the invention has the beneficial effects that:

(1) WO of the invention₃-TiO₂The electrochromic film has high light modulation amplitude (the light modulation amplitude of 633nm and 1600nm respectively reaches 66% and 60%) in a visible light region and a near infrared light region, has obvious selectively modulated double-frequency electrochromic effect, and can be changed among three optical states when an external voltage is changed: the glass has bright state (visible light and near infrared are transmitted), cold state (visible light is transmitted and near infrared is blocked) and dark state (visible light and near infrared are blocked), and has wide application prospect in the fields of building energy-saving glass and the like.

(2) The invention adopts a hydrothermal method to grow nano-scale TiO on conductive glass₂Array film due to TiO₂Has the advantages ofHydrophilicity and special array structure, facilitate WO₃In TiO₂WO of crystallization and growth on arrayed thin films and favoring intercalated water structure₃Forming; TiO 2₂Array Structure and WO₃The nano structure increases the specific surface area of the film, can shorten the diffusion path of ions and is beneficial to the rapid embedding and releasing of the ions in the material; the monoclinic phase intercalation water structure can obviously reduce WO₃The energy barrier of the medium ion diffusion increases the ion flux, thereby improving the coloring efficiency.

(3) The preparation method is simple, low in equipment requirement, low in cost, low in energy consumption, pollution-free, controllable in product and easy to realize on-line large-area film coating.

Drawings

FIG. 1 is an XRD pattern of the products of example 1, comparative example 1 and comparative example 2, wherein h-WO₃Denotes hexagonal phase WO₃，o-WO_3`H₂O represents monoclinic phase intercalation water structure WO₃And FTO represents FTO conductive glass.

FIG. 2 is an SEM image of the products of example 1, comparative example 1 and comparative example 2, wherein A is TiO in comparative example 1₂SEM image of array, B is WO of comparative example 2₃SEM picture of (B), C is WO obtained in example 1₃-TiO₂Surface topography of electrochromic film, D is WO prepared in example 1₃-TiO₂And (3) a profile topography of the electrochromic film.

FIG. 3 is a graph showing the transmittance change at different voltages for the products of example 1, example 2, comparative example 1 and comparative example 2; wherein A is comparative example 1, B is comparative example 2, C is example 1, and D is example 2.

FIG. 4 shows WO obtained in example 1₃-TiO₂The electrochromic film is an optical picture under different electrochemical states, wherein A is a bright state (visible light and near infrared are transmitted), B is a cold state (visible light is transmitted and near infrared is blocked), and C is a dark state (visible light and near infrared are blocked).

FIG. 5 is a plot of cyclic voltammograms of the products of example 1, comparative example 1 and comparative example 2.

FIG. 6 is a drawing showingWO obtained in example 1₃-TiO₂Graph of in-situ transmittance change of the electrochromic film during electrochemical cycling.

FIG. 7 shows WO obtained in example 1₃-TiO₂The coloring efficiency of the electrochromic film is shown in the graph, wherein A is the coloring efficiency at 633nm, B is the coloring efficiency at 1600nm, and CE represents the coloring efficiency.

Detailed Description

The invention is further elucidated with reference to the figures and the examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Example 1

(1) Mixing 30mL of concentrated hydrochloric acid, 30mL of deionized water and 1.2mL of butyl titanate, and uniformly mixing by magnetic stirring for 1h to prepare a titanium dioxide precursor solution; FTO conductive glass (30mm multiplied by 1mm) is ultrasonically cleaned by deionized water and alcohol and then is placed into a 50mL high-pressure reaction kettle lining, 20mL titanium dioxide precursor liquid is added into the FTO conductive glass to carry out hydrothermal reaction, and the hydrothermal reaction conditions are as follows: at 130 ℃ for 2 h; preparation of the product with TiO₂Conductive glass of the array;

(2) dissolving 3.3g of sodium tungstate dihydrate in 120mL of deionized water, heating and stirring at 70 ℃ for 30min, placing in cold water for cooling, and adding 100mL of 0.25mol/L HCl solution until no precipitate is generated; the supernatant was removed, the precipitate was washed with deionized water until the pH of the wash was 2.4 for a total volume of 120mL, followed by 3mL of 30 wt.% H₂O₂Stirring the solution at 70 deg.C for 1h to dissolve precipitate completely to obtain clear WO₃A precursor solution;

(3) will carry TiO₂The conductive glass of the array is placed into a 50mL high-pressure reaction kettle lining, and then 20mL WO is added₃Adding 0.01g of urea into the precursor solution to perform secondary hydrothermal reaction at the temperature of 160 ℃ for 3 hours to prepare the WO₃-TiO₂An electrochromic film.

Example 2

(1) Mixing 30mL of concentrated hydrochloric acid, 30mL of deionized water and 0.9mL of butyl titanate, magnetically stirring for 1h, and mixing uniformly to prepare the titanium dioxideDraining; FTO conductive glass (30mm multiplied by 1mm) is ultrasonically cleaned by deionized water and alcohol and then is placed into a 50mL high-pressure reaction kettle lining, 20mL titanium dioxide precursor liquid is added into the FTO conductive glass to carry out hydrothermal reaction, and the hydrothermal reaction conditions are as follows: at 130 ℃ for 2 h; preparation of the product with TiO₂Conductive glass of the array;

(2) dissolving 3.3g of sodium tungstate dihydrate in 120mL of deionized water, heating and stirring at 70 ℃ for 30min, placing in cold water for cooling, and adding 100mL of 0.25mol/L HCl solution until no precipitate is generated; the supernatant was removed, the precipitate was washed with deionized water until the pH of the wash was 2.4 for a total volume of 120mL, followed by 3mL of 30 wt.% H₂O₂Stirring the solution at 70 deg.C for 1h to dissolve precipitate completely to obtain clear WO₃A precursor solution;

(3) will carry TiO₂The conductive glass of the array is placed into a 50mL high-pressure reaction kettle lining, and then 20mL WO is added₃Adding 0.01g of urea into the precursor solution to perform secondary hydrothermal reaction at the temperature of 160 ℃ for 2.5 hours to prepare the WO₃-TiO₂An electrochromic film.

Comparative example 1

Mixing 30mL of concentrated hydrochloric acid, 30mL of deionized water and 1.2mL of butyl titanate, and uniformly mixing by magnetic stirring for 1h to prepare a titanium dioxide precursor solution; FTO conductive glass (30mm multiplied by 1mm) is ultrasonically cleaned by deionized water and alcohol and then is placed into a 50mL high-pressure reaction kettle lining, 20mL titanium dioxide precursor liquid is added into the FTO conductive glass to carry out hydrothermal reaction, and the hydrothermal reaction conditions are as follows: at 130 ℃ for 2 h; preparation of the product with TiO₂Conductive glass of the array.

Comparative example 2

Dissolving 3.3g of sodium tungstate dihydrate in 120mL of deionized water, heating and stirring at 70 ℃ for 30min, placing in cold water for cooling, and adding 100mL of 0.25mol/L HCl solution until no precipitate is generated; the supernatant was removed, the precipitate was washed with deionized water until the pH of the wash was 2.4 for a total volume of 120mL, followed by 3mL of 30 wt.% H₂O₂Stirring the solution at 70 deg.C for 1h to dissolve precipitate completely to obtain clear WO₃A precursor solution;

FTO conductive glass (30mm multiplied by 1mm) is ultrasonically cleaned by deionized water and alcohol and then is placed into a 50mL high-pressure reaction kettle lining, and then 20mL WO is added₃Adding 0.01g of urea into the precursor solution to perform hydrothermal reaction under the following conditions: 160 ℃ for 3 h; preparation of a compound with WO₃Conductive glass of nanorods.

Sample analysis

FIG. 1 is an XRD pattern of the products of example 1, comparative example 1 and comparative example 2, and comparing them, it can be seen that TiO of rutile structure is only present in comparative example 1₂(r-TiO₂) No other phase of TiO was found₂The peak position of (a); WO in comparative example 2₃Predominantly hexagonal phase WO₃(h-WO₃) While a small amount of monoclinic phase intercalated water structure WO is also present₃(o-WO_{3`</sub>H<sub>2</sub>O); in example 1, however, r-TiO is present at the same time<sub>2</sub>、h-WO<sub>3</sub>And o-WO<sub>3`}H₂Three phases of O, and WO₃Mainly o-WO_{3`</sub>H<sub>2</sub>The state of O being present, h-WO<sub>3</sub>The peak position of (a) is weak. Description of TiO<sub>2</sub>The presence of an array is advantageous for o-WO<sub>3`}H₂And (4) generating O. o-WO_3`H₂The generation of O can be obviously reduced₃The energy barrier of medium ion diffusion increases the ion flux and obviously promotes WO₃-TiO₂The electrochromic property of the electrochromic film is that,

FIG. 2 is an SEM image of the products of example 1, comparative example 1 and comparative example 2, wherein A is TiO in comparative example 1₂SEM image of the array; b is WO in comparative example 2₃SEM picture of (1); c is WO obtained in example 1₃-TiO₂A surface topography map of the electrochromic film; d is WO obtained in example 1₃-TiO₂And (3) a profile topography of the electrochromic film. It can be seen that WO grown directly on FTO conductive glass₃Film made of WO in nano-rod shape₃In the electrochromic film of example 1, TiO was deposited₂WO grown on arrays₃The film is formed by co-stacking of nanocrystals and nanorods, and WO₃The nano-rod and the nano-crystal not only cover the TiO₂Forming a film on the surface of the array, and filling the film in TiO₂In the interstices of the array, TiO₂The thickness of the array is about 150-250 nm; WO₃-TiO₂The thickness of the electrochromic film is about 350-500 nm.

Fig. 3 is a graph showing the transmittance change at different voltages for the products of example 1, example 2, comparative example 1 and comparative example 2. Pure TiO, shown as A in FIG. 3₂The transmittance change of the array is very slight when a negative voltage is applied, as shown by B in FIG. 3, pure WO₃The film mainly shows a certain modulation effect in a near infrared region, and the light modulation amplitude in a visible region is smaller, while WO₃-TiO₂Electrochromic film relatively pure TiO₂Arrays and pure WO₃The modulation amplitude of the film is significantly increased and a significant "dual-frequency" modulation effect is exhibited, as shown by C in fig. 3, the modulation amplitudes at 633nm and 1600nm of example 1 are 68.4% and 59.8%, respectively, and the modulation amplitudes at 633nm and 1600nm of example 2 are 54.0% and 59.5%, respectively, as shown by D in fig. 3.

FIG. 4 shows WO of example 1₃-TiO₂Optical pictures of electrochromic films in the "bright state", "cold state" and "dark state", where A is the "bright state", WO₃-TiO₂The electrochromic film appears white; b is "cold", WO₃-TiO₂The electrochromic film appears light blue; c is "dark state", WO₃-TiO₂The electrochromic film exhibited a deep blue color.

FIG. 5 is a cyclic voltammogram of the products of example 1, comparative example 1 and comparative example 2. The shape of the curve is typical of redox reactions, representing the coloration and bleaching processes in electrochromic reactions. Pure WO of comparative example 2₃Film and WO of example 1₃-TiO₂The cyclic voltammograms of the electrochromic films were similar in shape. With pure TiO of comparative example 1₂Array and comparative example 2 pure WO₃Film comparison, WO of example 1₃-TiO₂The area of the electrochromic film cyclic voltammetry scanning is larger, which shows that TiO₂Arrays and WO₃The electrochemical performance of the film is improved by compounding, and the current density of the electrochromic film is higher, namely the density of the exchange charges is higher, which shows thatLi in electrochromic film at given voltage⁺The intercalation and deintercalation reactions of (a) occur more easily.

FIG. 6 shows WO of example 1₃-TiO₂The in-situ transmittance change curve of the electrochromic film in the electrochemical cycle process. The response time is defined as the time required for the sample to reach its 90% light modulation amplitude. By calculation, the response times of coloring and discoloring at 633nm of the electrochromic film of example 1 were 11s and 3.6s, respectively, and the response times of coloring and discoloring at 1600nm were 3s and 9.4s, respectively.

FIG. 7 shows WO obtained in example 1₃-TiO₂The coloring efficiency of the electrochromic film is shown in the graph, wherein A is the coloring efficiency at 633nm, B is the coloring efficiency at 1600nm, and CE represents the coloring efficiency. As can be seen from FIG. 7, WO of example 1₃-TiO₂The electrochromic film has higher coloring efficiency at 633nm and 1600nm, and the coloring efficiency is respectively 180.5cm²C and 639.4cm²and/C. The faster response time and high coloring efficiency are mainly due to TiO₂And WO₃The nano structure increases the specific surface area of the film, shortens the diffusion path of ions and is beneficial to the rapid embedding and releasing of the ions in the film; the monoclinic phase intercalation water structure can obviously reduce WO₃The energy barrier for medium ion diffusion increases the ion flux.

The embodiments described above are intended to illustrate the technical solutions of the present invention in detail, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modification, supplement or similar substitution made within the scope of the principles of the present invention should be included in the protection scope of the present invention.