H2o2 sensitized amorphous ti o2 photocatalytic active material and preparation method thereof

Abstract

The application discloses a hydrogen peroxide (H2O2) sensitized amorphous titanium dioxide (TiO2) photocatalytic active material and a preparation method thereof. The method comprises the following steps: firstly, cleaning and pretreating a substrate; secondly, depositing an amorphous TiO2 layer on the surface of the clean substrate by using a room temperature physical vapor deposition method; thirdly, immersing the substrate into a H2O2 solution for one-step sensitization and activation at room temperature; and fourthly, in-situ generating a peroxotitanium active complex on the surface of the amorphous TiO2 to obtain the target photocatalytic active material. The material can effectively activate the intrinsic photocatalytic activity of the amorphous TiO2 through the peroxotitanium active complex, and can be applied to the fields of water organic pollutant degradation, air purification, photocatalytic micro-nano devices and the like. The application does not need high-temperature crystallization treatment above 400 DEG C, and does not need complex modification steps such as noble metal loading and element doping, and has the advantages of simple and efficient process, low energy consumption, low cost, compatibility with various rigid and flexible substrates, and easy realization of large-area and large-scale preparation.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic functional materials technology, and specifically relates to an amorphous titanium dioxide (TiO2) photocatalytic active material that can be prepared at room temperature and sensitized by hydrogen peroxide (H2O2) and its general preparation method. Background Technology

[0002] Photocatalytic active materials have irreplaceable application value in the degradation of organic pollutants in water, air purification, photocatalytic hydrogen production, and photocatalytic micro / nano devices, and are one of the core materials for solving current environmental pollution and energy shortage problems. Titanium dioxide (TiO2) has become the most widely used photocatalytic active material globally due to its excellent chemical stability, wide availability of raw materials, low cost, and non-toxicity. Currently, most TiO2 photocatalytic active materials commonly used in commercial and research fields are anatase or rutile phase crystalline structures, and their photocatalytic activity strictly depends on high-temperature crystallization treatment above 400℃. This high-temperature annealing step not only significantly increases the complexity and time cost of the preparation process, but also greatly increases the energy consumption of industrial production, and is incompatible with flexible substrates such as polymers that are not heat-resistant, limiting its integrated application in flexible photocatalytic devices.

[0003] In recent years, amorphous TiO2 has attracted widespread attention due to its advantage of not requiring high-temperature crystallization. However, unmodified pure amorphous TiO2 has inherent defects such as extremely fast intrinsic carrier recombination rate and ineffective activation of surface active sites, which cannot directly meet the needs of practical applications. Existing modification methods mainly include noble metal loading and element doping. For example, CN202111060502.X discloses an amorphous TiO2 / Ag composite nanoparticle, which improves the photoelectrocatalytic performance of amorphous TiO2 by loading and modifying it with silver nanoparticles. However, this method requires the separate preparation of TiO2 precursor solution and silver nanoparticle solution, followed by a 5-15 hour ultraviolet light irradiation recombination reaction. The process steps are cumbersome and rely on the noble metal silver as the modifying component, which significantly increases the preparation cost. At the same time, the product is in powder form, making it difficult to directly prepare large-area uniform films. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a hydrogen peroxide (H2O2)-sensitized amorphous TiO2 photocatalytic active material and its preparation method. This method involves directly depositing amorphous TiO2 at room temperature via radio frequency magnetron sputtering, followed by one-step sensitization and activation with H2O2 solution. This sensitization and activation generates an in-situ titanium peroxide active complex on the surface of the amorphous TiO2, effectively activating its intrinsic photocatalytic activity. This preparation process is simple and efficient, requiring no high-temperature crystallization treatment above 400℃, nor complex modification steps such as noble metal loading or elemental doping. It features low energy consumption, low cost, compatibility with various substrates, and ease of large-scale preparation.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: In a first aspect, the present invention provides an H2O2-sensitized amorphous TiO2 photocatalytic active material, characterized in that it includes a substrate and an amorphous TiO2 layer deposited on the surface of the substrate; the amorphous TiO2 layer is a completely amorphous structure and does not require high-temperature crystallization treatment above 400°C; the surface of the amorphous TiO2 layer contains an in-situ generated titanium peroxide active complex, which has photocatalytic activity under ultraviolet light irradiation.

[0006] Furthermore, the substrate is selected from any one of glass, quartz, monocrystalline silicon, polystyrene (PS), polylactic acid (PLA), and polyethylene terephthalate (PET); the thickness of the amorphous TiO2 layer is 10 nm to 500 nm.

[0007] In a second aspect, the present invention provides a method for preparing H2O2-sensitized amorphous TiO2 photocatalytic active material as described in the first aspect, characterized by comprising the following steps: S1, substrate preparation; S2, deposition of amorphous TiO2 on the substrate; S3, sensitization treatment of the amorphous TiO2.

[0008] As a preferred embodiment, the substrate preparation in step S1 specifically involves: selecting a suitable cleaning solvent based on the substrate material; for substrates resistant to organic solvents such as glass, quartz, and monocrystalline silicon, ultrasonically cleaning with acetone, anhydrous ethanol, and deionized water for 10 to 20 minutes each in sequence; for polymer substrates not resistant to organic solvents such as polyethylene terephthalate (PET), ultrasonically cleaning with deionized water for 15 to 30 minutes; and then drying with high-purity nitrogen to obtain a clean pretreated substrate.

[0009] As a preferred embodiment, the amorphous TiO2 deposition in step S2 specifically involves: placing the pretreated substrate into the cavity of an RF magnetron sputtering instrument, using a TiO2 ceramic target with a purity ≥ 99.99% as the target material, and evacuating to a base vacuum level ≤ 3×10⁻⁶. -3 Argon gas with a purity ≥ 99.99% is introduced to a working pressure of 0.5 Pa to 1.5 Pa. The sputtering power is set to 50 W to 150 W and the sputtering time is 1 h to 10 h to deposit an amorphous TiO2 layer on the substrate surface.

[0010] As a preferred embodiment, the H2O2 sensitization treatment in step S3 specifically involves immersing the substrate with the deposited amorphous TiO2 layer into an H2O2 solution with a volume fraction of 1% to 10%, and allowing it to stand at room temperature for 1 to 20 minutes for sensitization and activation, thereby obtaining the H2O2-sensitized amorphous TiO2 photocatalytic active material.

[0011] The beneficial effects of the present invention are: (1) The preparation process is simple, energy consumption is low, and it is easy to scale up production: the high temperature heat treatment step of 400°C or above required for traditional crystalline TiO2 is completely eliminated, which greatly reduces the energy consumption and time cost of preparation; at the same time, the damage to the substrate material caused by high temperature treatment is avoided.

[0012] (2) One-step sensitization with H2O2 without complex modification: Due to the one-step sensitization process of immersing in H2O2 solution at room temperature, abundant active titanium peroxide complexes can be generated in situ on the surface of amorphous TiO2, which fully activates its intrinsic catalytic activity. There is no need for complex modification steps such as noble metal loading and element doping, which greatly simplifies the preparation process.

[0013] (3) Strong substrate compatibility and wide range of applications: Due to the use of room temperature deposition process, it is compatible with a variety of rigid and flexible substrates such as glass, quartz, single crystal silicon, polystyrene (PS), polylactic acid (PLA), and polyethylene terephthalate (PET), and can prepare large-area photocatalytic active films. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a SEM image of the amorphous TiO2 thin film in Example 1 of the present invention.

[0016] Figure 2 This is an XRD image of the amorphous TiO2 thin film in Example 1 of the present invention.

[0017] Figure 3 This is a schematic diagram of the preparation method in this invention.

[0018] Figure 4 This is a schematic diagram illustrating the principle of H2O2 sensitization in this invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0020] Example 1 This embodiment provides a glass-based H2O2-sensitized amorphous TiO2 photocatalytic active material, the structure of which includes a glass substrate and an amorphous TiO2 layer with a thickness of about 10 nm deposited on the surface of the glass substrate. The preparation steps of the material include: S1, substrate pretreatment; S2, amorphous TiO2 deposition; S3, H2O2 sensitization and activation.

[0021] Further, the substrate pretreatment in step S1 specifically involves: ultrasonically cleaning a 2cm×2cm ordinary glass slide with acetone, anhydrous ethanol, and deionized water for 15 minutes each, and then drying it with nitrogen gas for later use.

[0022] Further, the amorphous TiO2 deposition in step S2 specifically involves: placing the pretreated glass slide into the cavity of an RF magnetron sputtering instrument, using a TiO2 ceramic target with a purity of 99.99% as the target material, and evacuating to a base vacuum level of 3 × 10⁻⁶. -3 At 0.5 Pa, 99.99% pure argon gas was introduced to the working pressure. The sputtering power was set to 50 W and the sputtering time was 1 h. An amorphous TiO2 layer was deposited on the glass slide surface at room temperature.

[0023] Further, the H2O2 sensitization and activation in step S3 specifically involves immersing a glass slide with deposited amorphous TiO2 into a 2% (v / v) H2O2 solution and allowing it to stand at room temperature for 10 minutes to obtain the H2O2-sensitized amorphous TiO2 photocatalytic active material.

[0024] Example 2 This embodiment provides a silicon wafer substrate H2O2-sensitized amorphous TiO2 photocatalytic active material, the structure of which includes a silicon wafer substrate and an amorphous TiO2 layer with a thickness of approximately 110 nm deposited on the surface of the silicon wafer substrate. The preparation steps of the material include: S1, substrate pretreatment; S2, amorphous TiO2 deposition; S3, H2O2 sensitization and activation.

[0025] Further, the substrate pretreatment in step S1 specifically involves: ultrasonically cleaning a 2cm×2cm silicon wafer with acetone, anhydrous ethanol, and deionized water for 15 minutes each, and then drying it with nitrogen gas for later use.

[0026] Further, the amorphous TiO2 deposition in step S2 specifically involves: placing the pretreated silicon wafer into the cavity of an RF magnetron sputtering instrument, using a TiO2 ceramic target with a purity of 99.99% as the target material, and evacuating to a base vacuum level of 2.5 × 10⁻⁶. -3 At 1.0 Pa, 99.99% pure argon gas was introduced to the working pressure, sputtering power was set to 120 W, sputtering time was 3 h, and an amorphous TiO2 layer was deposited on the silicon wafer surface at room temperature.

[0027] Further, the H2O2 sensitization and activation in step S3 specifically involves immersing a silicon wafer with deposited amorphous TiO2 in a 3% (v / v) H2O2 solution and allowing it to stand at room temperature for 15 minutes to obtain the silicon wafer substrate H2O2-sensitized amorphous TiO2 photocatalytic active material.

[0028] Example 3: This embodiment provides a flexible PET substrate H2O2-sensitized amorphous TiO2 photocatalytic active material, the structure of which includes a 0.1 mm thick flexible PET substrate and an approximately 500 nm thick amorphous TiO2 layer deposited on the surface of the PET substrate. The preparation steps of the material include: S1, substrate pretreatment; S2, amorphous TiO2 deposition; S3, H2O2 sensitization and activation.

[0029] Further, the substrate pretreatment in step S1 specifically involves ultrasonically cleaning a 2cm×2cm PET substrate with deionized water for 20 minutes and then drying it with nitrogen gas for later use.

[0030] Further, the amorphous TiO2 deposition in step S2 specifically involves: placing the pretreated PET substrate into the cavity of an RF magnetron sputtering instrument, using a TiO2 ceramic target with a purity of 99.99% as the target material, and evacuating to a base vacuum level of 2.0 × 10⁻⁶. -3 At 1.5 Pa, 99.99% pure argon gas was introduced to the working pressure, the sputtering power was set to 150 W, the sputtering time was 8 h, and an amorphous TiO2 layer was deposited on the PET substrate surface at room temperature.

[0031] Further, the H2O2 sensitization and activation in step S3 specifically involves immersing a PET substrate with deposited amorphous TiO2 into a 10% (v / v) H2O2 solution and allowing it to stand at room temperature for 1 minute to obtain the PET substrate H2O2-sensitized amorphous TiO2 photocatalytic active material.

[0032] Example 4: This embodiment provides a biodegradable PLA substrate H2O2-sensitized amorphous TiO2 photocatalytic active material, the structure of which includes a PLA biodegradable substrate with a thickness of 0.15 mm and an amorphous TiO2 layer with a thickness of approximately 90 nm deposited on the surface of the PLA substrate. The preparation steps of the material include: S1, substrate pretreatment; S2, amorphous TiO2 deposition; S3, H2O2 sensitization and activation.

[0033] Further, the substrate pretreatment in step S1 specifically involves: ultrasonically cleaning a 2cm×2cm PLA substrate with deionized water for 10 minutes and then drying it with nitrogen gas for later use.

[0034] Further, the amorphous TiO2 deposition in step S2 specifically involves: placing the pretreated PLA substrate into the cavity of an RF magnetron sputtering instrument, using a TiO2 ceramic target with a purity of 99.99% as the target material, and evacuating to a base vacuum level of 1.5 × 10⁻⁶. -3 At a working pressure of 1.2 Pa, 99.99% pure argon gas was introduced and the sputtering power was set to 50 W. The sputtering time was 10 h. An amorphous TiO2 layer was deposited on the PLA substrate at room temperature.

[0035] Further, the H2O2 sensitization activation in step S3 specifically involves immersing a PLA substrate with deposited amorphous TiO2 in a 1% (v / v) H2O2 solution and allowing it to stand at room temperature for 20 minutes to obtain the PLA substrate H2O2-sensitized amorphous TiO2 photocatalytic active material.

[0036] In addition to the specific embodiments disclosed above, the present invention can also be modified as follows: 1. The polymer substrate may also be made of other commonly used polymer materials such as polycarbonate (PC), polypropylene (PP), and polyethylene (PE); 2. The deposition process of amorphous TiO2 can also employ other room-temperature physical vapor deposition methods such as electron beam deposition and pulsed laser deposition; 3. The volume fraction of H2O2 sensitization treatment can be adjusted within the range of 1% to 10%, and the treatment time can be adjusted within the range of 1 to 20 minutes.

[0037] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A hydrogen peroxide (H2O2)-sensitized amorphous titanium dioxide (TiO2) photocatalytic active material, characterized in that, It includes a substrate and an amorphous TiO2 layer deposited on the surface of the substrate; the amorphous TiO2 layer has a completely amorphous structure and its surface contains in-situ generated titanium peroxide active complexes.

2. The H2O2-sensitized amorphous TiO2 photocatalytic active material according to claim 1, characterized in that, The substrate is selected from any one of glass, quartz, monocrystalline silicon, polystyrene, polylactic acid, polyethylene terephthalate, polycarbonate, polypropylene, and polyethylene.

3. The H2O2-sensitized amorphous TiO2 photocatalytic active material according to claim 1, characterized in that, The thickness of the amorphous TiO2 layer is 10 nm to 500 nm.

4. A method for preparing the H2O2-sensitized amorphous TiO2 photocatalytic active material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Clean the substrate to obtain a clean substrate; S2. An amorphous TiO2 layer is deposited on the surface of the clean substrate using room temperature physical vapor deposition. S3. Immerse the substrate with the deposited amorphous TiO2 layer in H2O2 solution and perform sensitization and activation treatment at room temperature to obtain the H2O2-sensitized amorphous TiO2 photocatalytic active material.

5. The preparation method according to claim 4, characterized in that, The cleaning pretreatment described in step S1 is as follows: For substrates resistant to organic solvents, ultrasonically clean them sequentially with acetone, anhydrous ethanol, and deionized water for 10 to 20 minutes each; for polymer substrates not resistant to organic solvents, ultrasonically clean them with deionized water for 15 to 30 minutes; after cleaning, dry them with high-purity nitrogen.

6. The preparation method according to claim 4, characterized in that, The room temperature physical vapor deposition method described in step S2 is selected from any one of radio frequency magnetron sputtering, electron beam deposition, and pulsed laser deposition.

7. The preparation method according to claim 6, characterized in that, Step S2 involves depositing an amorphous TiO2 layer using radio frequency magnetron sputtering. Specifically, a TiO2 ceramic target with a purity ≥ 99.99% is used as the target material. The vacuum level is evacuated to a base vacuum of ≤ 3×10⁻³Pa. Argon gas with a purity ≥ 99.99% is introduced to a working pressure of 0.5 Pa to 1.5 Pa. The sputtering power is set to 50 W to 150 W, and the sputtering time is 1 h to 10 h. An amorphous TiO2 layer is deposited on the substrate surface at room temperature.

8. The preparation method according to claim 4, characterized in that, The volume fraction of the H2O2 solution in step S3 is 1% to 10%.

9. The preparation method according to claim 4, characterized in that, The sensitization and activation treatment in step S3 takes 1 to 20 minutes.

10. The preparation method according to claim 4, characterized in that, The sensitization and activation treatment in step S3 is a static soaking treatment, and no external light, heating or stirring is required during the sensitization process.

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