Titanium dioxide film as well as preparation method and application thereof
By controlling the preferential growth of titanium dioxide thin films using electron beam evaporation deposition and pre-melting treatment, the problems of high cost and low adhesion in existing technologies have been solved, and the preparation of titanium dioxide thin films with high photocatalytic performance has been realized.
Patent Information
- Application Number
- CN202511148897.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-15
- Publication Date
- 2025-12-02
AI Technical Summary
Existing methods for preparing titanium dioxide thin films are costly, have low adhesion, poor adaptability, and are difficult to achieve optimal crystal plane growth, thus affecting photoelectric performance and photocatalytic efficiency.
The electron beam evaporation deposition method was used to introduce oxygen into a vacuum environment to convert titanium pentoxide into titanium dioxide. The titanium dioxide was then preferentially grown along the (004) crystal plane on the substrate surface through pre-melting treatment and plasma-assisted deposition technology. Annealing treatment was then used to improve adhesion and adaptability.
A low-cost, high-adhesion, and highly adaptable titanium dioxide film preparation method has been achieved, which improves photocatalytic efficiency and adhesion to the substrate, and is suitable for photocatalytic degradation of dyeing and printing wastewater.
Smart Images
Figure CN121046779A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thin film preparation methods, and in particular to a titanium dioxide thin film, its preparation method, and its application. Background Technology
[0002] Preferred growth of titanium dioxide (TiO2) films refers to the preferential orientation of crystal growth along a specific crystal direction. Due to the exposure of specific crystal planes with high energy, the performance of TiO2 films can be significantly improved, such as enhancing photoelectric properties, improving charge transport, and increasing photocatalytic efficiency.
[0003] Traditional processes use hydrothermal synthesis or magnetron sputtering to prepare titanium dioxide thin films with preferred crystal planes. However, hydrothermal synthesis requires specific precursors, which are very complex and costly to synthesize, and the resulting titanium dioxide thin films have low adhesion and poor adaptability to the shape and pattern of the substrate. Magnetron sputtering is also costly. Summary of the Invention
[0004] Based on this, this application provides a titanium dioxide thin film, its preparation method and application. The preparation method is simple and low in cost, and the prepared titanium dioxide thin film has strong adhesion and strong adaptability to substrates.
[0005] The first aspect of this application provides a method for preparing a titanium dioxide thin film, comprising the following steps: providing a substrate; using electron beam evaporation deposition to deposit a thin film on the surface of the substrate using an evaporation source material; wherein, in the electron beam evaporation deposition method: the reaction gas includes oxygen, and the oxygen flow rate is 40 sccm to 80 sccm; annealing the deposited film to prepare a titanium dioxide thin film; the titanium dioxide in the titanium dioxide thin film preferentially grows along the (004) crystal plane; the evaporation source material includes titanium pentoxide.
[0006] In some implementations, plasma-assisted deposition is combined with electron beam evaporation deposition.
[0007] In some embodiments, the evaporation source material is a pre-melted evaporation source raw material; the D50 particle size of the evaporation source material is 2mm~5mm; the pre-melting treatment includes three pre-melting processes, with an interval of 5min~15min between adjacent pre-melting processes, and the pre-melting temperature of each of the three pre-melting processes is independently 1700℃~1900℃, the heating rate of each is independently 5℃ / min~10℃ / min, and the vacuum degree of each is independently 1×10 -5 Torr~5×10 -5 Torr; The pre-melting process also includes the following steps: cooling the pre-melted evaporation source material to room temperature, with a vacuum degree of 1×10. -5 Torr~5×10 -5Torr.
[0008] In some embodiments, the process parameters for forming a deposited thin film on the substrate surface using electron beam evaporation deposition include at least one of the following features (1)-(4):
[0009] (1) The temperature of the substrate is 60℃~100℃.
[0010] (2) The evaporation rate is 1 Å / s to 5 Å / s.
[0011] (3) The thickness of the deposited film is 50nm~1000nm.
[0012] (4) The vacuum degree is 1×10 -5 Torr~6×10 -5 Torr.
[0013] In some embodiments, the substrate comprises quartz glass and / or borosilicate glass.
[0014] In some implementations, the step of providing the substrate is followed by the following steps:
[0015] The substrate was subjected to plasma bombardment cleaning.
[0016] In some embodiments, the plasma bombardment cleaning process includes: placing the substrate on a coating holder, closing the furnace door, evacuating the furnace, turning on the ion source filament, and setting the operating parameters; the operating parameters include at least one of the following features (1) to (7):
[0017] (1) The argon flow rate is 10 sccm~50 sccm.
[0018] (2) The vacuum degree is 2×10 -5 Torr~8×10 -5 Torr.
[0019] (3) The cleaning time is 5 min to 30 min.
[0020] (4) The filament current is 15A~30A.
[0021] (5) The filament voltage is 15V~30V.
[0022] (6) The discharge current is 5A~10A.
[0023] (7) The discharge voltage is 100V~150V.
[0024] In some embodiments, the annealing temperature is 300°C to 650°C.
[0025] The second aspect of this application provides a titanium dioxide thin film prepared using the titanium dioxide thin film preparation method provided in the first aspect of this application.
[0026] The third aspect of this application provides the application of titanium dioxide films prepared using the method for preparing titanium dioxide films as provided in the first aspect of this application in the photocatalytic degradation of dyeing and printing wastewater.
[0027] Compared with the prior art, this application has the following beneficial effects:
[0028] This application utilizes electron beam evaporation deposition to introduce oxygen into a vacuum environment, thereby converting titanium pentoxide into titanium dioxide and allowing it to preferentially grow along the (004) crystal plane on the substrate surface, thus achieving the control of the preferential growth of titanium dioxide material in the thin film.
[0029] The preparation method of this application is simple and low in cost, and the prepared titanium dioxide film has strong adhesion and strong adaptability to substrates. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a schematic diagram of a method for preparing a titanium dioxide thin film according to one embodiment of this application.
[0032] Figure 2 This is the X-ray diffraction pattern of the titanium dioxide material in the titanium dioxide thin film in Example 1 of this application.
[0033] Figure 3 This is the X-ray diffraction pattern of the titanium dioxide material in the titanium dioxide thin film in Example 2 of this application.
[0034] Figure 4 The X-ray diffraction patterns of titanium dioxide materials in titanium dioxide thin films in Examples 3 and 2 of this application are shown.
[0035] Figure 5 This is the X-ray diffraction pattern of the titanium dioxide material in the titanium dioxide thin film in Example 4 of this application.
[0036] Figure 6 This is the X-ray diffraction pattern of the titanium dioxide material in the titanium dioxide thin film in Example 5 of this application.
[0037] Figure 7The X-ray diffraction pattern of the titanium dioxide material in the titanium dioxide thin film in Comparative Example 1 of this application is shown.
[0038] Figure 8 The X-ray diffraction patterns of titanium dioxide materials in titanium dioxide thin films in Examples 6 and 3 of this application are shown. Detailed Implementation
[0039] A detailed reference is now provided to embodiments of this application, one or more of which are described below. Each embodiment is provided for explanation and not for limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to this application without departing from its scope or spirit. For example, features described or illustrated as part of one embodiment may be used in another embodiment to produce further embodiments.
[0040] Therefore, this application is intended to cover such modifications and variations falling within the scope of the appended claims and their equivalents. Other objects, features, and aspects of this application are disclosed in or will be apparent from the following detailed description. It will be understood by those skilled in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of this application.
[0041] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.
[0042] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.
[0043] In this article, when referring to units of data ranges, if a unit is only followed by the right endpoint, it means that the units of the left and right endpoints are the same.
[0044] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.
[0045] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.
[0046] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.
[0047] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.
[0048] like Figure 1 As shown, the first aspect of this application provides a method for preparing a titanium dioxide (TiO2) thin film, comprising the following steps: S1, providing a substrate.
[0049] S2. Electron beam evaporation deposition is used to form a thin film on the substrate surface from the evaporation source material. In electron beam evaporation deposition, the reaction gas includes oxygen, and the oxygen flow rate is 40 sccm to 80 sccm.
[0050] S3. Anneal the deposited film to prepare a titanium dioxide film.
[0051] Titanium dioxide in the titanium dioxide thin film preferentially grows along the (004) crystal plane.
[0052] The evaporation source material includes titanium pentoxide.
[0053] In this application, "preferred crystal facet growth" refers to the phenomenon that certain specific crystal faces grow preferentially during the crystal growth process due to their lower energy or more favorable growth conditions.
[0054] This application utilizes electron beam evaporation deposition to convert titanium pentoxide into titanium dioxide under vacuum conditions by introducing oxygen. The titanium dioxide is then preferentially and directionally grown along the (004) crystal plane on the substrate surface, thus achieving the control of the preferential growth of titanium dioxide material in the thin film. The preferential growth of titanium dioxide along the (004) crystal plane improves the photocatalytic efficiency of the titanium dioxide thin film.
[0055] The preparation method of this application is simple and low in cost, and the prepared titanium dioxide film has strong adhesion and strong adaptability to substrates.
[0056] The deposition process of the thin film in this application is as follows: In a vacuum evaporation coating machine, electron evaporation deposition technology is used. Under vacuum conditions, titanium pentoxide is heated by an electron gun evaporator, causing titanium pentoxide to undergo gaseous sublimation. The gaseous titanium pentoxide reacts with oxygen introduced into the chamber to generate titanium dioxide gaseous molecules. The titanium dioxide gaseous molecules diffuse to the substrate surface to form a deposited thin film.
[0057] It is understandable that the oxygen flow rate is 40 sccm to 80 sccm, including but not limited to 40 sccm, 50 sccm, 60 sccm, 70 sccm, and 80 sccm.
[0058] Understandably, the oxygen flow rate can be controlled by a flow controller, allowing oxygen to be introduced into the chamber simultaneously during the electron evaporation process to prevent oxygen deficiency during titanium pentoxide evaporation and ensure that titanium pentoxide can be completely converted into titanium dioxide.
[0059] In some embodiments, in the step of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the temperature of the substrate is 60°C to 100°C, including but not limited to 60°C, 70°C, 80°C, 85°C, 90°C, and 100°C.
[0060] In some embodiments, in the step of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the evaporation rate is 1 Å / s to 5 Å / s, including but not limited to 1 Å / s, 2 Å / s, 3 Å / s, 4 Å / s, and 5 Å / s.
[0061] In some embodiments, in the step of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the thickness of the deposited thin film is 50nm~1000nm, including but not limited to 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, and 1000nm.
[0062] In some embodiments, in the step of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the vacuum level is 1×10⁻⁶. -5 Torr~6×10 -5 Torr, including but not limited to 1×10 -5 Torr, 2×10 -5 Torr, 3×10 -5 Torr, 4×10 -5 Torr, 5×10 -5 Torr, 6×10 -5 Torr.
[0063] In some implementations, plasma-assisted deposition is combined with electron beam evaporation deposition.
[0064] In some embodiments, the vacuum level in plasma-assisted deposition is 1×10⁻⁶. -4 Torr~4×10 -4 Torr, including but not limited to 1×10 -4 Torr, 2×10 -4 Torr, 3×10 -4 Torr, 4×10 -4 Torr. By controlling the vacuum level within a suitable range to avoid energy dispersion caused by excessive collisions of gas molecules, the directional bombardment energy of ions is guaranteed.
[0065] In some implementations, the plasma gas used in plasma-assisted deposition is argon (Ar).
[0066] This application employs plasma-assisted deposition technology during electron beam evaporation deposition, using ions of a certain energy to bombard the film being deposited. This causes the deposited molecules or atoms to be continuously bombarded by ions from the ion source, thereby gaining greater momentum to increase the compactness of the film and improve its performance stability.
[0067] In some implementations, the evaporation source material is a pre-melted evaporation source raw material.
[0068] In some embodiments, the D50 particle size of the evaporation source material is 2mm to 5mm, including but not limited to 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.
[0069] If the D50 particle size of the evaporation source material is too small, the material is prone to splashing under the bombardment of the electron beam, causing fluctuations in the evaporation rate. If the D50 particle size of the evaporation source material is too large, heat transfer is uneven, and the surface of the material may melt while the center remains unmelted, resulting in low evaporation efficiency. Therefore, this application sets the D50 particle size of the evaporation source material to 2mm~5mm to avoid material splashing and improve evaporation stability and efficiency.
[0070] In some embodiments, the pre-melting process includes three pre-melting steps: a first pre-melting, a second pre-melting, and a third pre-melting, to melt the particles into a homogeneous liquid. The interval between any two adjacent pre-melting steps is 5 to 15 minutes. By controlling the interval between any two adjacent pre-melting steps within a suitable range, on the one hand, oxygen is completely removed to prevent excessive oxidation of titanium pentoxide; on the other hand, surface stress is released, and phase transformation stress is conducted to the center of the material, preventing microcracks or spattering.
[0071] The process parameters for the first pre-melting include: pre-melting temperature of 1700℃~1900℃, heating rate of 5℃ / min~10℃ / min, and vacuum degree of 1×10⁻⁶. -5 Torr~5×10 -5 Torr. The process parameters for the second and third pre-melting are independent and include: pre-melting temperature of 1700℃~1900℃, heating rate of 5℃ / min~10℃ / min, and vacuum degree of 1×10. - 5 Torr~5×10 -5 Torr.
[0072] Furthermore, the process parameters for the first pre-melting, the second pre-melting, and the third pre-melting are the same.
[0073] If the pre-melting temperature is too low, titanium heptoxide may remain, leading to abnormal conductivity of the thin film. If the pre-melting temperature is too high, titanium atoms may sublimate directly, resulting in metal doping within the thin film and affecting its performance. Therefore, this application controls the pre-melting temperature to be 1700℃~1900℃ to avoid titanium heptoxide residue, prevent metal doping in the film layer, and improve the film performance.
[0074] This application eliminates residual gases and impurities in the titanium pentoxide film material through three pre-melting processes, reduces residual bubbles, improves the purity of the titanium pentoxide film material, and enhances the stability of the evaporation source.
[0075] In some implementations, the pre-melting process also includes a cooling step.
[0076] The cooling process includes: after turning off the heating, the titanium pentoxide raw material obtained by pre-melting treatment is naturally cooled to room temperature to ensure that the surface of the titanium pentoxide material is smooth and free of bubbles.
[0077] In some embodiments, the vacuum level during the cooling process is 1×10⁻⁶. -5 Torr~5×10 -5 Torr, including but not limited to 1×10 -5 Torr, 2×10 -5 Torr, 3×10 -5 Torr, 4×10 -5 Torr, 5×10 -5 Torr.
[0078] It should be noted that the room temperature in this application refers to 15℃~35℃.
[0079] In some embodiments, the step of forming a deposited thin film on the substrate surface using electron beam evaporation deposition includes fixing the substrate to the workpiece umbrella, wherein the rotation speed of the umbrella during the coating process is 10 rpm to 30 rpm, including but not limited to 10 rpm, 15 rpm, 20 rpm, 25 rpm, and 30 rpm.
[0080] In some embodiments, the substrate comprises quartz glass and / or borosilicate glass.
[0081] In some embodiments, the substrate provided is a substrate that has undergone ultrasonic cleaning.
[0082] In some implementations, the step of providing the substrate is followed by the following steps:
[0083] The substrate was subjected to plasma bombardment cleaning.
[0084] In some implementations, the Ar flow rate in the plasma bombardment cleaning process is 10 sccm to 50 sccm, including but not limited to 10 sccm, 20 sccm, 30 sccm, 40 sccm, and 50 sccm.
[0085] In some embodiments, the vacuum level in the plasma bombardment cleaning process is 2 × 10⁻⁶. -5 Torr~8×10 -5 Torr, including but not limited to 2×10 -5 Torr, 3×10 -5 Torr, 4×10 -5 Torr, 5×10 -5 Torr, 6×10 -5 Torr, 7×10 -5 Torr, 8×10 -5 Torr.
[0086] In some embodiments, the cleaning time in plasma bombardment cleaning is 5 min to 30 min, including but not limited to 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min.
[0087] In some embodiments, the filament current in the plasma bombardment cleaning process is 15A to 30A, including but not limited to 15A, 20A, 25A, and 35A.
[0088] In some embodiments, the filament voltage in the plasma bombardment cleaning process is 15V~30V, including but not limited to 15V, 20V, 25V, and 35V.
[0089] In some embodiments, the discharge current in the plasma bombardment cleaning process is 5A to 10A, including but not limited to 5A, 7A, 9A, and 10A.
[0090] In some embodiments, the discharge voltage in the plasma bombardment cleaning process is 100V~150V, including but not limited to 100V, 110V, 120V, 130V, 140V, and 150V.
[0091] Prior to forming a deposited thin film on the substrate surface using electron beam evaporation deposition, this application performs plasma bombardment cleaning on the substrate to increase the surface energy of the substrate and enhance the adhesion between the substrate and the deposited thin film.
[0092] In one specific embodiment, the ultrasonically cleaned quartz glass substrate is placed on the coating fixture, the furnace door is closed, and the chamber vacuum pressure is evacuated to 5 × 10⁻⁶. -5 Toor, turn on the ion source filament and set the operating parameters as follows: filament current 22A, filament voltage 22V, discharge current 7A, discharge voltage 125V; ion bombardment time 15min, argon (Ar) flow rate 30sccm.
[0093] In some embodiments, the annealing temperature is 300°C to 650°C, including but not limited to 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, and 650°C. Annealing increases the crystallinity of the deposited film.
[0094] The second aspect of this application provides a titanium dioxide thin film prepared using the titanium dioxide thin film preparation method provided in the first aspect of this application.
[0095] The third aspect of this application provides the application of titanium dioxide films prepared using the method for preparing titanium dioxide films as provided in the first aspect of this application in the photocatalytic degradation of dyeing and printing wastewater.
[0096] Furthermore, this application provides the following specific embodiments and comparative examples to further illustrate the specific implementation of this application and its advantages.
[0097] Example 1
[0098] The borosilicate glass substrate was subjected to ultrasonic cleaning.
[0099] Next, the borosilicate glass substrate undergoes plasma bombardment cleaning. Specifically, the ultrasonically cleaned borosilicate glass is placed on a coating holder, the furnace door is closed, and the chamber vacuum pressure is evacuated to 5 × 10⁻⁶. -5Toor, turn on the ion source filament and set the parameters as follows: filament current 22A, filament voltage 22V, discharge current 7A, discharge voltage 125V; set the ion bombardment working time to 15min and the Ar flow rate to 30sccm.
[0100] Titanium pentoxide (Ti3O5, D50 3 mm) was placed in a crucible and pre-melted. Specifically, the titanium pentoxide underwent a first pre-melting treatment at 1800℃ with a heating rate of 8℃ / min. After a 10-min interval, a second pre-melting treatment was performed at 1800℃ with a heating rate of 8℃ / min. After a 10-min interval, a third pre-melting treatment was performed at 1800℃ with a heating rate of 8℃ / min. After all three pre-melting treatments, the heating was turned off, and the mixture was allowed to cool naturally to room temperature to prepare the coating.
[0101] Using a vacuum coating machine, the substrate is fixed to the workpiece umbrella. Under vacuum conditions, the coating material (Ti3O5) is heated through an electron gun evaporator, causing the Ti3O5 to become a gaseous phase. During the heating and evaporation process, oxygen is introduced into the chamber. The gaseous Ti3O5 reacts with the oxygen to generate gaseous TiO2, which diffuses to the substrate surface to form a deposited thin film. The rotation speed of the workpiece umbrella is 20 rpm, the substrate temperature is 80℃, and the vacuum degree is 3 × 10⁻⁶. -5 The oxygen flow rate was 60 sccm, the deposition rate was 3 Å / s, and the thickness of the deposited film was 500 nm. Plasma-assisted deposition was used during the film formation process, and the working vacuum level after Ar gas priming was controlled at 2.5 × 10⁻⁶. -4 Toor.
[0102] Titanium dioxide thin films were prepared by annealing the deposited thin films at 500℃.
[0103] Example 2
[0104] The preparation method of this embodiment is basically the same as that of Example 1. The main difference is that in Example 2, during the process of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the oxygen flow rate is 40 sccm. Specifically:
[0105] Using a vacuum coating machine, the substrate is fixed to the workpiece umbrella. Under vacuum conditions, the coating material (Ti3O5) is heated through an electron gun evaporator, causing the Ti3O5 to become a gaseous phase. During the heating and evaporation process, oxygen is introduced into the chamber. The gaseous Ti3O5 reacts with the oxygen to generate gaseous TiO2, which diffuses to the substrate surface to form a deposited thin film. The rotation speed of the workpiece umbrella is 20 rpm, the substrate temperature is 80℃, and the vacuum degree is 3 × 10⁻⁶. -5The oxygen flow rate was 40 sccm, the deposition rate was 3 Å / s, and the thickness of the deposited film was 500 nm. Plasma-assisted deposition was used during the film formation process, and the working vacuum level after Ar gas priming was controlled at 2.5 × 10⁻⁶. -4 Toor.
[0106] Example 3
[0107] The preparation method of this embodiment is basically the same as that of Example 1. The main difference is that in Example 3, during the process of forming a deposited thin film on the substrate surface using electron beam evaporation deposition, the oxygen flow rate is 80 sccm. Specifically:
[0108] Using a vacuum coating machine, the substrate is fixed to the workpiece umbrella. Under vacuum conditions, the coating material (Ti3O5) is heated through an electron gun evaporator, causing the Ti3O5 to become a gaseous phase. During the heating and evaporation process, oxygen is introduced into the chamber. The gaseous Ti3O5 reacts with the oxygen to generate gaseous TiO2, which diffuses to the substrate surface to form a deposited thin film. The rotation speed of the workpiece umbrella is 20 rpm, the substrate temperature is 80℃, and the vacuum degree is 3 × 10⁻⁶. -5 The oxygen flow rate was 80 sccm, the deposition rate was 3 Å / s, and the thickness of the deposited film was 500 nm. Plasma-assisted deposition was used during the film formation process, and the working vacuum level after Ar gas priming was controlled at 2.5 × 10⁻⁶. -4 Toor.
[0109] Example 4
[0110] The preparation methods of this embodiment and Example 1 are basically the same. The main difference is that the annealing temperature in Example 4 is 300°C. Specifically, the deposited film is annealed at 300°C to prepare a titanium dioxide film.
[0111] Example 5
[0112] The preparation methods of this embodiment and Example 1 are basically the same. The main difference is that the annealing temperature in Example 5 is 650°C. Specifically, the deposited film is annealed at 650°C to prepare a titanium dioxide film.
[0113] Example 6
[0114] The preparation methods of this embodiment and Example 1 are basically the same. The main difference is that the annealing temperature in Example 6 is 250°C. Specifically, the deposited film is annealed at 250°C to prepare a titanium dioxide film.
[0115] Comparative Example 1
[0116] The preparation methods of this comparative example and Example 1 are basically the same, the main difference being that in Comparative Example 1, the oxygen flow rate during the formation of the deposited thin film on the substrate surface using electron beam evaporation deposition is 30 sccm. Specifically:
[0117] Using a vacuum coating machine, the substrate is fixed to the workpiece umbrella. Under vacuum conditions, the coating material (Ti3O5) is heated through an electron gun evaporator, causing the Ti3O5 to become a gaseous phase. During the heating and evaporation process, oxygen is introduced into the chamber. The gaseous Ti3O5 reacts with the oxygen to generate gaseous TiO2, which diffuses to the substrate surface to form a deposited thin film. The rotation speed of the workpiece umbrella is 20 rpm, the substrate temperature is 80℃, and the vacuum degree is 3 × 10⁻⁶. -5 The oxygen flow rate was 30 sccm, the deposition rate was 3 Å / s, and the thickness of the deposited film was 500 nm. Plasma-assisted deposition was used during the film formation process, and the working vacuum level after Ar gas priming was controlled at 2.5 × 10⁻⁶. -4 Toor.
[0118] Comparative Example 2
[0119] The preparation methods of this comparative example and Example 1 are basically the same, the main difference being that in Comparative Example 2, during the formation of the deposited thin film on the substrate surface using electron beam evaporation deposition, the oxygen flow rate is 90 sccm. Specifically:
[0120] Using a vacuum coating machine, the substrate is fixed to the workpiece umbrella. Under vacuum conditions, the coating material (Ti3O5) is heated through an electron gun evaporator, causing the Ti3O5 to become a gaseous phase. During the heating and evaporation process, oxygen is introduced into the chamber. The gaseous Ti3O5 reacts with the oxygen to generate gaseous TiO2, which diffuses to the substrate surface to form a deposited thin film. The rotation speed of the workpiece umbrella is 20 rpm, the substrate temperature is 80℃, and the vacuum degree is 3 × 10⁻⁶. -5 The oxygen flow rate was 90 sccm, the deposition rate was 3 Å / s, and the thickness of the deposited film was 500 nm. Plasma-assisted deposition was used during the film formation process, and the working vacuum level after Ar gas priming was controlled at 2.5 × 10⁻⁶. -4 Toor.
[0121] Comparative Example 3
[0122] The preparation methods of this comparative example and Example 1 are basically the same, the main difference being that the deposited film was not annealed in Comparative Example 3.
[0123] Test case
[0124] (1) X-ray diffraction pattern (XRD) test
[0125] The crystal structure of the sample was characterized using an X-ray diffractometer (XRD, D8-ADVANCE type, Panalytical, Netherlands). Based on the crystal structure analysis, preferential growth of crystal planes was determined. The method for determining this was: if the intensity of the (004) crystal plane was higher than that of the (101) crystal plane, it indicated that the film underwent directional growth during deposition, with the growth direction being the c-axis. Among these, the (004) crystal plane was the highly photocatalytically active crystal plane.
[0126] like Figure 2 As shown, Figure 2 The X-ray diffraction pattern of titanium dioxide material in the titanium dioxide thin film in Example 1 of this application shows that the (004) crystal plane is the strongest characteristic peak, and titanium dioxide grows preferentially along the (004) crystal plane.
[0127] like Figure 3 As shown, Figure 3 The X-ray diffraction pattern of titanium dioxide material in the titanium dioxide thin film in Example 2 of this application shows that the (004) crystal plane is the strongest characteristic peak, and titanium dioxide grows preferentially along the (004) crystal plane.
[0128] like Figure 4 As shown, Figure 4 The X-ray diffraction patterns of titanium dioxide materials in titanium dioxide thin films in Examples 3 and 2 of this application are shown. The patterns show that the (004) crystal plane is the strongest characteristic peak, and titanium dioxide grows preferentially along the (004) crystal plane.
[0129] like Figure 5 As shown, Figure 5 The X-ray diffraction pattern of titanium dioxide material in the titanium dioxide thin film in Example 4 of this application shows that the (004) crystal plane is the strongest characteristic peak, and titanium dioxide grows preferentially along the (004) crystal plane.
[0130] like Figure 6 As shown, Figure 6 The X-ray diffraction pattern of titanium dioxide material in the titanium dioxide thin film in Example 5 of this application shows that the (004) crystal plane is the strongest characteristic peak, and titanium dioxide grows preferentially along the (004) crystal plane.
[0131] like Figure 7 As shown, Figure 7 The X-ray diffraction pattern of titanium dioxide material in the titanium dioxide thin film in Comparative Example 1 of this application shows that the (101) crystal plane is the characteristic peak and there is no preferential growth.
[0132] like Figure 8 As shown, Figure 8 The X-ray diffraction patterns of titanium dioxide materials in titanium dioxide films in Examples 6 and 3 of this application are shown. The patterns are basically diffuse peaks, with no preferred growth.
[0133] according to Figure 2 (Example 1) and Figure 7 The XRD patterns of (Comparative Example 1) show that when the oxygen flow rate is insufficient during the formation of the deposited thin film, it is not conducive to the preferential growth of titanium dioxide material.
[0134] according to Figure 2 (Example 1) and Figure 8 The XRD patterns of Example 6 and Comparative Example 3 show that when the deposited film is not annealed or the annealing temperature is insufficient, it is not conducive to the preferential growth of titanium dioxide material.
[0135] according to Figure 4 (Example 3 and Comparative Example 2) The oxygen content of Comparative Example 2 is 90%. At this time, the XRD pattern is the same as that of Example 3. The preferential growth intensity remains unchanged and reaches the limit value. At this time, due to the excessive oxygen content, the oxygen vacancy defect is reduced, which will lead to a sharp drop in photocatalytic efficiency. Specific data are shown in Table 1.
[0136] (2) Photocatalytic efficiency test
[0137] To prepare a 10 mg / L methyl orange solution, pour 75 cm 2 Borosilicate glass with a deposited titanium dioxide film was immersed in a methyl orange solution. The methyl orange solution was continuously stirred using a stirring device. The surface of the titanium dioxide film was irradiated with a 20W, 365nm ultraviolet lamp, and the absorbance of the methyl orange solution was measured. Since the absorbance of the solution is directly proportional to the concentration, the degradation rate of methyl orange can be calculated from the change in the absorbance of the methyl orange solution. The time required for the methyl orange solution to completely decolorize was recorded, which is the photocatalytic degradation efficiency of the titanium dioxide film, expressed in min / mL, i.e., the time required for complete degradation of 1 mL of methyl orange. The results are shown in Table 1 below.
[0138] Table 1
[0139]
[0140] As shown in Table 1, the photocatalytic efficiency of titanium dioxide thin films is improved by using the preparation method provided in this application to achieve preferential growth of titanium dioxide (004) crystal planes.
[0141] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0142] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method for preparing a titanium dioxide thin film, characterized in that, Includes the following steps: Provide a base; An electron beam evaporation deposition method is used to form a deposited thin film on the surface of the substrate by evaporating the source material; wherein, in the electron beam evaporation deposition method, the reaction gas includes oxygen, and the flow rate of the oxygen is 40 sccm~80 sccm; The deposited film is annealed to prepare a titanium dioxide film; The titanium dioxide in the titanium dioxide film preferentially grows along the (004) crystal plane; The evaporation source material includes titanium pentoxide.
2. The method for preparing titanium dioxide thin film according to claim 1, characterized in that, Plasma-assisted deposition is combined with electron beam evaporation deposition.
3. The method for preparing titanium dioxide thin film according to claim 1, characterized in that, The evaporation source material is a pre-melted evaporation source raw material; the D50 particle size of the evaporation source material is 2mm~5mm. The pre-melting process includes three pre-melting steps, with an interval of 5 to 15 minutes between each step. The pre-melting temperature for each step is independently 1700°C to 1900°C, the heating rate is independently 5°C / min to 10°C / min, and the vacuum degree is independently 1×10⁻⁶. -5 Torr~5×10 -5 Torr; The pre-melting process further includes: cooling the pre-melted evaporation source material to room temperature, with a vacuum degree of 1×10⁻⁶. -5 Torr~5×10 -5 Torr.
4. The method for preparing titanium dioxide thin film according to any one of claims 1-3, characterized in that, The process parameters for forming a deposited thin film on the substrate surface using electron beam evaporation deposition include at least one of the following features (1)-(4): (1) The temperature of the substrate is 60℃~100℃; (2) The evaporation rate is 1 Å / s to 5 Å / s; (3) The thickness of the deposited film is 50 nm to 1000 nm; (4) The vacuum degree is 1×10 -5 Torr~6×10 -5 Torr.
5. The method for preparing titanium dioxide thin film according to any one of claims 1-3, characterized in that, The substrate comprises quartz glass and / or borosilicate glass.
6. The method for preparing titanium dioxide thin film according to claim 5, characterized in that, The steps following the provision of the substrate include: The substrate is subjected to plasma bombardment cleaning.
7. The method for preparing titanium dioxide thin film according to claim 6, characterized in that, The plasma bombardment cleaning process includes: placing the substrate on a coating fixture, closing the furnace door, evacuating the furnace, turning on the ion source filament, and setting the operating parameters; the operating parameters include at least one of the following features (1) to (7): (1) The argon flow rate is 10 sccm to 50 sccm; (2) The vacuum degree is 2×10 -5 Torr~8×10 -5 Torr; (3) The cleaning time is 5 min to 30 min; (4) The filament current is 15A~30A; (5) The filament voltage is 15V~30V; (6) The discharge current is 5A~10A; (7) The discharge voltage is 100V~150V.
8. The method for preparing titanium dioxide thin film according to claim 1, characterized in that, The annealing temperature is 300℃~650℃.
9. A titanium dioxide thin film, characterized in that, The titanium dioxide thin film was prepared using the preparation method described in any one of claims 1-8.
10. The application of the titanium dioxide film prepared by the method of any one of claims 1 to 8 in the photocatalytic degradation of dyeing and printing wastewater.