A Ti2CT x / W 18 O 49 Application of a photoelectrochemical photodetector of heterojunction

Abstract

This invention relates to a Ti2CT-based x / W 18 O 49 Applications of heterojunction photoelectrochemical photodetectors. The fabrication process of this material utilizes Ti2CT. x The surface has an electronegativity characteristic, which makes it compatible with W 18 O 49 The positively charged W in the precursor 6+ After thorough integration, a novel heterojunction material, Ti2CT, was grown in situ using a simple one-pot hydrothermal method. x / W 18 O 49 By constructing heterojunctions to prevent Ti2CT x Nanosheets are re-stacking, and the optimized band structure promotes photogenerated carrier separation, thereby effectively improving the photoresponse performance of the material. This invention is the first synthesis of Ti2CT. x / W 18 O 49 Heterojunction materials were developed and applied to the field of photoelectric detection. The photoelectric detection performance of this material was superior to that of Ti2CT alone. x or W 18 O 49 It shows significant improvement, and the preparation process is simple and low-cost, which can be used for large-scale preparation, further expanding the application prospects of MXene materials and photodetectors.

Description

Technical Field

[0001] This invention belongs to the field of photoelectrochemical detection, specifically relating to a method based on Ti2CT. x / W 18 O 49 Applications of heterojunction photoelectrochemical photodetectors. Background Technology

[0002] Photodetectors, as sensors that convert light signals into receivable and processable electrical signals, are widely used in fields such as solar power generation, biomedicine, environmental monitoring, and remote control. Photoelectrochemical photodetectors are a novel type of photodetector whose working principle is based on the semiconductor-liquid contact mechanism. When a semiconductor comes into contact with a liquid, electrons and holes separate under the influence of the built-in electric field formed at the interface. Therefore, photoelectrochemical photodetectors can generate high current response and fast response speed without an external power supply, and can even operate stably in emergency situations such as power outages, greatly expanding their applications in real-world scenarios.

[0003] As a core component of photodetectors, the material properties of the working electrode have a crucial impact on the detector's detection capability. Therefore, researching and improving suitable working electrode materials is of great significance to the advancement of photodetector research. Ti2CT x As a novel two-dimensional layered semiconductor material, Ti2CT has broad application prospects in the field of photoelectric detection. However, Ti2CT... x Problems such as nanosheet recombination and photogenerated carrier recombination still exist. This invention addresses these issues through Ti2CT... x Surface in-situ growth W 18 O 49 Nanospheres can effectively inhibit Ti2CT x The stacking of nanosheets and the optimized band structure promote efficient separation of photogenerated electron-hole pairs, thereby improving the photoelectric detection performance of the material. This invention features a simple fabrication process, allowing for the preparation of materials via a simple one-pot hydrothermal method, and significantly improves the photoresponse performance of the material, further expanding the applications of Ti2CT. x The application prospects of other MXene materials in the field of photoelectric detection. Summary of the Invention

[0004] The purpose of this invention is to provide a Ti2CT-based... x / W 18 O 49 Heterojunction photoelectrochemical photodetector.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a novel heterojunction material, Ti2CT. x / W 18 O 49 The photodetector, wherein the photodetector is a photoelectrochemical photodetector with titanium carbide / tungsten oxide as the working electrode, includes the following steps:

[0007] 1) The aluminum titanium carbide powder was dissolved in hydrochloric acid mixed with lithium fluoride for etching treatment. It was then washed with dilute hydrochloric acid and deionized water. The titanium carbide product was dissolved in N-methyl-2-pyrrolidone solution for ultrasonic treatment. It was then washed twice each with acetone, anhydrous ethanol and deionized water. After drying, the exfoliated two-dimensional titanium carbide nanosheet sample was obtained.

[0008] 2) The sample obtained in step 1) and tungsten hexachloride were added to anhydrous ethanol solution, stirred and hydrothermally treated, and then washed twice with anhydrous ethanol and twice with deionized water. After drying, a two-dimensional titanium carbide / tungsten oxide heterostructure (Ti2CT) was obtained. x / W 18 O 49 )sample;

[0009] 3) Dissolve the sample obtained in step 2) in deionized water and sonicate to obtain uniformly dispersed titanium carbide / tungsten oxide (Ti2CT) x / W 18 O 49 Dispersion;

[0010] 4) The substrate ITO conductive glass was cleaned with acetone and anhydrous ethanol and dried to obtain a pure sample.

[0011] 5) Spin-coat the dispersion obtained in step 3) onto a sample sheet obtained in step 4), and dry it to obtain the working electrode of the photodetector;

[0012] 6) The working electrode obtained in step 5) is subjected to photoelectric performance testing in an electrochemical workstation system to obtain the photodetector performance.

[0013] According to a preferred embodiment of the present invention, in the etching process of step 1), the mass of aluminum titanium carbide is 500 mg, the mass of lithium fluoride is 800 mg, the etching temperature and time are 40°C and 48 h, respectively; in the ultrasonic treatment, the mass of titanium carbide powder is 200 mg, the volume of N-methyl-2-pyrrolidone solution is 80 mL, the ultrasonic treatment time is 24 h, the cleaning time of acetone, anhydrous ethanol and deionized water is 30 min each, the drying temperature is -60°C and the drying time is 36 h.

[0014] According to a preferred embodiment of the present invention, in step 2), the sample mass is 40 mg, the tungsten hexachloride mass is 35 mg, the anhydrous ethanol volume is 6 mL, the hydrothermal temperature and time are 200°C and 10 h respectively, the washing time with anhydrous ethanol and deionized water is 30 min each, the drying temperature is -60°C, and the drying time is 36 h.

[0015] According to a preferred embodiment of the present invention, in step 3), the solid-liquid mass-volume ratio of the sample to deionized water is 10 mg:10 mL, and the ultrasonic treatment time is 30 min.

[0016] According to a preferred embodiment of the present invention, in step 4), the soaking and cleaning time for acetone and anhydrous ethanol is 15 min each.

[0017] According to a preferred embodiment of the present invention, in step 5), the volume of the dispersion liquid for spin coating is 1 mL, the drying temperature is 60°C, and the drying time is 12 h.

[0018] According to a preferred embodiment of the present invention, in step 6), the applied voltage during the test is 0.4 V, and the light intensity is 40, 80, 120, and 160 mW / cm². 2 The photodetector uses 0.1, 0.2, 0.5 and 1.0 M Na2SO4 solutions as electrolytes, and the excitation light source has a wavelength range of 390-780 nm.

[0019] All equipment and raw materials used in the method of this invention are commercially available products.

[0020] Based on the above technical solution, the present invention has the following advantages:

[0021] (1) This invention discovers through research that, through the use of MXene material Ti2CT x Upper in situ growth W 18 O 49 This allows for the acquisition of a heterojunction material, Ti2CT, with significant photoresponse properties. x / W 18 O 49 Its band structure can promote the transfer of photogenerated electrons and holes in the photoelectrochemical process, thereby achieving significant photoelectric detection performance.

[0022] (2) Through research, the present invention has found that the prepared photoelectrochemical photodetector is inexpensive, has a simple manufacturing process, can effectively respond to light of different intensities, and can improve its photodetection performance by adjusting the electrolyte concentration. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below:

[0024] Figure 1 The heterojunction material Ti2CT prepared in this invention x / W 18 O 49 SEM image.

[0025] Figure 2 The heterojunction material Ti2CT prepared in this invention x / W 18 O 49 Raman spectrum.

[0026] Figure 3 This is a physical image of the working electrode of the photodetector prepared according to the present invention.

[0027] Figure 4 The heterojunction material Ti2CT prepared in this invention x / W 18 O 49 Homogeneous Ti2CT x W 18 O 49 A comparison chart of optical detection performance.

[0028] Figure 5 The Ti2CT-based material prepared in this invention x / W 18 O 49 The photodetector operates at 40, 80, 120, and 160 mW / cm². 2 Light response curves under different light intensities.

[0029] Figure 6 The Ti2CT-based material prepared in this invention x / W 18 O 49 Photoresponse curves of the photodetector at electrolyte concentrations of 0.1, 0.2, 0.5, and 1.0 M. Detailed Implementation

[0030] The present invention will be further described in detail below through specific embodiments, wherein the raw materials are all industrially produced products. These embodiments are for illustrative purposes only and should not be construed as limiting the invention. Modifications or alterations of equivalent forms of the invention by those skilled in the art also fall within the scope defined by the appended claims.

[0031] Example 1:

[0032] The prepared Ti2CT-coated materials were spin-coated separately. x W 18 O 49 Ti2CT x / W 18 O 49 ITO conductive glass was used as the working electrode in a standard three-electrode electrochemical system for photoelectrochemical testing. The counter electrode was a platinum sheet electrode, and the reference electrode was a silver chloride electrode. A 350W xenon lamp was used as the illumination source, with light intensities of 80 and 120 mW / cm². 2 The test was conducted under the conditions of 0.5 M Na2SO4 solution as electrolyte and 0.4 V applied bias voltage, with alternating light and dark exposures at a period of 10 s. Figure 4 As shown, at 80 and 120 mW / cm 2 Ti2CT under two illumination intensities x / W 18 O 49 The light response intensity is higher than that of Ti2CT x and W 18 O 49 At a light intensity of 80 mW / cm 2 At that time, Ti2CT x / W 18 O 49 The light response intensity is respectively higher than that of Ti2CT x and W 18 O 49 The increases were 65.2% and 111.1% higher; at a light intensity of 120 mW / cm². 2 At that time, Ti2CT x / W 18 O 49 The light response intensity is respectively higher than that of Ti2CT x and W 18 O 49 The increases of 62.2% and 114.3% demonstrate the superiority of MXene materials in Ti2CT. x Upper in situ growth W 18 O 49 The obtained heterojunction material has a significant performance improvement compared to the single material.

[0033] Example 2:

[0034] The prepared spin-coated Ti2CT x / W 18 O 49 ITO conductive glass was used as the working electrode in a standard three-electrode electrochemical system for photoelectrochemical testing. The counter electrode was a platinum sheet electrode, and the reference electrode was a silver chloride electrode. A 350W xenon lamp was used as the illumination source, with illumination intensities of 40, 80, 120, and 160 mW / cm². 2 Under conditions of 0.5 M Na₂SO₄ solution as electrolyte and 0.4 V applied bias voltage, tests were conducted with alternating periods of light and darkness, each lasting 10 seconds. Figure 5 As shown, with the light intensity increasing from 40 to 160 mW / cm 2 Continuously enhanced, based on heterojunction Ti2CT x / W 18 O 49 The photocurrent of the photodetector increased from 0.35 µA / cm² to 0.65 µA / cm². 2 This proves that it can effectively respond to light of different intensities.

[0035] Example 3:

[0036] The prepared spin-coated Ti2CT x / W 18 O 49 ITO conductive glass was used as the working electrode in a standard three-electrode electrochemical system for photoelectrochemical testing. The counter electrode was a platinum sheet electrode, and the reference electrode was a silver chloride electrode. A 350W xenon lamp was used as the illumination source at a light intensity of 120 mW / cm². 2 Under conditions where the electrolyte is 0.1, 0.2, 0.5, or 1.0 M Na₂SO₄ solution, and the applied bias voltage is 0.4 V, tests were conducted with alternating periods of light and darkness, each lasting 10 seconds. Figure 6 As shown, with the solution concentration increasing from 0.1 to 1.0 M, the heterojunction-based Ti2CT... x / W 18 O 49 The photocurrent of the photodetector increased from 0.2 to 0.68 µA / cm. 2 This demonstrates that the photodetector performance can be improved by adjusting the electrolyte concentration.

Claims

1. A Ti2CT-based x / W 18 O 49 The fabrication method of a heterojunction photoelectrochemical photodetector includes the following steps: 1) The aluminum titanium carbide powder was dissolved in hydrochloric acid mixed with lithium fluoride for etching treatment. It was then washed with dilute hydrochloric acid and deionized water. The titanium carbide product was dissolved in N-methyl-2-pyrrolidone solution for ultrasonic treatment. It was then washed twice each with acetone, anhydrous ethanol and deionized water. After drying, the exfoliated two-dimensional titanium carbide nanosheet sample was obtained. 2) The sample obtained in step 1) and tungsten hexachloride were added to anhydrous ethanol solution, stirred and hydrothermally treated, and then washed twice with anhydrous ethanol and twice with deionized water. After drying, two-dimensional titanium carbide / tungsten oxide Ti2CT was obtained. x / W 18 O 49 Heterojunction samples; 3) Dissolve the sample obtained in step 2) in deionized water and sonicate to obtain uniformly dispersed titanium carbide / tungsten oxide Ti2CT. x / W 18 O 49 Dispersion; 4) The substrate ITO conductive glass was cleaned with acetone and anhydrous ethanol and dried to obtain a pure sample. 5) Spin-coat the dispersion obtained in step 3) onto a sample sheet obtained in step 4), and dry it to obtain the working electrode of the photodetector; 6) The working electrode obtained in step 5) is subjected to photoelectrochemical performance testing in an electrochemical workstation system to obtain the photodetector performance.

2. The preparation method according to claim 1, characterized in that, In step 1), the etching process used 500 mg of aluminum titanium carbide and 800 mg of lithium fluoride. The etching temperature and time were 40°C and 48 h, respectively. In the ultrasonic treatment, the titanium carbide powder used 200 mg of titanium carbide and the N-methyl-2-pyrrolidone solution was 80 mL. The ultrasonic treatment time was 24 h. The cleaning time with acetone, anhydrous ethanol, and deionized water was 30 min each. The drying time was 36 h.

3. The preparation method according to claim 1, characterized in that, In step 2), the sample mass was 40 mg, the tungsten hexachloride mass was 35 mg, the anhydrous ethanol volume was 6 mL, the hydrothermal temperature and time were 200°C and 10 h, the washing time with anhydrous ethanol and deionized water was 30 min each, and the drying time was 36 h.

4. The preparation method according to claim 1, characterized in that, In step 3), the solid-liquid mass-volume ratio of the sample to deionized water is 10 mg:10 mL, and the ultrasonic treatment time is 30 min.

5. The preparation method according to claim 1, characterized in that, In step 4), the soaking and cleaning time for acetone and anhydrous ethanol is 15 min each.

6. The preparation method according to claim 1, characterized in that, In step 5), the volume of the dispersion for spin coating is 1 mL, the drying temperature is 60℃, and the drying time is 12 h.

7. The preparation method according to claim 1, characterized in that, In step 6), a voltage of 0.4 V was applied during the test, and the light intensity was 40, 80, 120, and 160 mW / cm². 2 The photodetector uses 0.1, 0.2, 0.5 and 1.0 M Na2SO4 solutions as electrolytes, and the excitation light source has a wavelength range of 390-780 nm.

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